CHEMISTRY I

I I
I
Metallurgy

Metals are used to make parts for gadgets like Smart watches, T\/, fridge
and computers. Paints have powdered graphite in them which is a non-metal.
Carbon atoms arrangement in paint's graphite helps in offering authentic
protection.

Chapter Topics
ii Metals and Non Met als

il Occurence

ii Metallurgy

il Aluminimum
 I TOPIC 1 I
METALS AND NON METALS

M tals ll be drawn into wires, beaten into sheets

e h'ch have either 1, 2 or 3 electrons in valence she 'can ,
The elements w I k n as metals.
lustrous and behave as conductors are now d tides Any metal can lose a minimum of
are . h' h ositively charge par · h
Metals loose electrons to fo rm cations w IC are p r of electrons present in outermost s elQ. They forrn
1 and maxim um of 3 elect rons (which depend on the numbe
basic oxides.

Example 1. Na - e- - Na+ "t will loose 1 electron

Ans. Sodium have 1 electron in valence shell (2, 8, 1). Hence, I

Ex:amp_le 2. Name the first metal to be used by man.

Ans. Copper was the first metal to be used by man.

Non Metals . h ll can't be drawn into wires, and can't be beaten

The elements which have 5, 6, or 7 electrons in valenceds . e ' l tors The oxides of non-metals are acidic or
into sneets are non-metals. These are non-lustrous an insu a ·
neutral in nature. · d f l
Non-metals accepts electrons to form anions which are negatively charge par IC es.
· h It depends one number of electrons present
Non-metals accept minimum one electron and maximum t ree.
in outermost shell
F + e - - F-
[F(g), (2, 7) have 7 electrons in outermost shell. Hence, it requires only 1 electron to complete its octet

~ Important
... Hydrogen is a non-metal which also forms positive ions.

Activity series (Metals)

The arrangement of metals in the decreasing order of their reactivity is called reactivity or activity series of
metals.

Main Features of Activity Series

• Metals lying above in activity series can displace the metals lying below, from their salt solutions.
• Metals lying above hydrogen are more electro positive than the metals lying below hydrogen.
• Metals lying below hydrogen do not displace hydrogen from water and dilute acids.
• It also helps to find that the reaction is feasible (possible) or not.

Example 3. Why Gold, platinum and copper exist in free state?

Ans. Gold, platinum and copper exist in free state because they are unreactive in nature.
Example 4. Why metals placed below hydrogen do not displace hydrgen from acid?
An1. It is because they are less reactive than hydrogen.
Example 5. Which type of oxide is formed by
(A) Metals (B) Non- metals
Ans. (A) Metals form Basic oxides.
(8) No n-metals form acidic oxides.

Example 6. Name the metallic oxides which are amphote • .

ric in nature
Ans. Aluminium (Al20 3) ·
Zinc oxide (ZnO)

3861:8 Edut:;'ort ICSE Chemistry Class X

 ITOPIC 21
Metals 0CCURENCE
Th e earth's crus t is the big ges t sou
h
Most oft e met a ls are reac tive rce of met als M t l ·
so th : e a s can either occur in free stat
sulphides, sulp hate s etc. e or in a com bined stat e.
ey occ ur in combined stat e in form
of their oxides, carbon ate, hali des,
Minerals and Ores
Minerals are the natu rall y occ urin
g com
d rocks etc. The se eart hly imp u y nd
tan , . pou s of met als which are mixed
n ies are call ed gan gue or matrix. with othe r substances such as soil
0 es are thos e min eral s from whi ch met l
r
6'.} Important a s are extr acte d cheaply, profitab
ly and conveniently .
_. All minerals are not ores but all ores
are minerals.

Some commonly use d ores and thei r

che mic al form ulae are:

ore
(1)
Chemical name
Bau xite F6rrriula
(2) Hyd rate d Aluminium oxide
Cry olit e Al203.2H 20
(3) Sodium Aluminimum Fluoride
Hae mat ite Na3AlF6
(4) Ferric oxide
Ma gne tite Fe203
Ferrous oxide
(5) Zinc Ble nde Fe304
Zinc sulphide
(6) Cop per Pyr ite Zns
Chalco pyrite
CuFeS2

METALLURGY
The process of extr acti ng of met al from
its ore by physical or chemical proc
ess is known as met allu rgy.
It involves various pro ces ses. Th e pro
cess es ·1n volved during metallurgy are:
,,
" Ore ,
Hand picking
~~- Crushing and grinding_
Pulverising
Froth floatation
Magnetic separation
~-- ---1 ratio--:: -:-7 --4 ,--_ Gravity sepa ratio
Concent1~- n of Ore n
Chemical method

Roas ting or calcination

Met als

o r
Metallurgy /1!J 387
 lverising.
oc es s is ca lle d pu
h d ball mills •The pr
. .
crus er s an tra tio n o f ores.
. fine powder 1n big fro m or e is ca lle d concen
im pu rit ies
,nto al of ga ng ue . '
• Ores are crushed va en t ra te
,
su lp hi de or es .
Th rocess of re mo is used to co . nc
• eP ~, t tion process
(l) Froth , ,o a a ne tic ores.
n is used for m ag · d. ·t Y
Magnetic separatio f
o ore an rmpurr
m
(3) Gravity separa
tion de pe nd s on de ns ity
uxite.
(4) Chemical m et
ho d is used for Ba tion. •
ed to .re m ov e n, 0 rsture
te d to ei th er "R oasting or 'Calcina·d th " th e y ar e usls d
d ore is subjec B
r es is nv en of f by three
c.
• The concentrate
, O
rts oxrde ,o rm. es e im pu rit ie s ar e a
, ·
co nv er t or e in to til
ar e used to d porour. Th e vo
la
• These processes ll as to make it light an
or es as we
from th e
methods. . .
thl s.
olved m s proces
. The S0 2 gas is ev
~ Im po rt an t
in pres en ce of air and used for su lph ide ores
se nce of air. CO 2 gas is ev olved in this process.
.,. Roasting is do ne ores in ab cing agents).
n is do ne for hy droxide or carbonate ele ctr ol ysis or by smelting (using redu
.,. While Calcina tio r by
ore) is reduced eithe
e m etallic ox ide (R oasted or calcinated
.,. Th
to give m et al .
Exampl_e '?. What is smelting? of ore (ro as te d or ca lc in ated) is re du ce d
in wh ich th e oxide
Ans. It is a process g an d calcination?
oduc ed as th e result of roastin fr om ca lc in at io n.
Exam ple 8. Which
ga s is pr
ile CO (c ar bo n dioxide) re su lts
m roasting wh 2
e (SOi) results fro
Ans. Sulphur dioxid is refined to re m ov e up impurities.
ed m et al or m at rix .
• Afte r reduct ion ,
th e ex tra ct
ci at ed wi th or e is ca lle d "Gangue
purities as so g.
wa nt ed ea rth ly im fo rm of fusible sla
• Gangue: The un ch ar ge to re m ov e ga ng ue in
de d with th e et al s is ca[! d
A ch em ica l su bs ta nc e which is ad ng ue du rin g th e ex tra ct io n of m e
• Flux: n flux re ac tion with ga
w he
product formed
• Slag: The fusible
m~ ula also.
tw o or es of Iro n. Give their form
any
Example 9. Name
Fe 0
Ans. H ae m atite: 2 3
Magnetite: Fe 30 4 als with?
es th e m etallurgy process de re of all oys.
Exam ple 10 . To w
ha t do
ica tio n of m et al s an d m an uf ac tu
uction an d purif
de al s with th e prod
Ans. Metallurgy

ALUMIN IMUM .
crust It is . do es n' t occu r fre e
.. e m os t ab un da nt m et al in th
e ea rth
· a reactive m et al an
d he nc e, it
~ Lum1n1mum is th scovered by "Oersted" in 182 5.
in natu re. It w as di
Symbo l Al
Atom ic no.: 13
Atomic m ass: 27
Val.ency: 3
tion = 2, 8, 3
Electronic co nfigura oup (Ill A) or 13
ta bl e = Period 1/1, Gr
Po sition in pe rio dic

Extraction d th e process of extr f

t, in 18 85, de ve lope ac ron of Aluminim
um
• Ha ll an d Hero ul inim um is . .
ore of Alum 8
te (Al20 3. 2H 20 )
The m os t co m m on th e thau x1
n e concentr arion of ore is done.
he d an d gr ind ed
The ore is fir st crus '
1rri
d d·u
. . by Bayer's pr oces s: In this .
ite is m ·ixed with tra te so
fi~ on of Ba ux ite roc~ss, first Ba ux co nc en
• Pu ri uc tion 0 f Spodu,m Alu .
which result in prod
hydroxide solution, H minate.
Al 20 3.2H20 + 2NaO -- . 2NaAlO + 3H o
2 2
(cone.)

~RR rrrr ICSE Chemistry ass

Cl x
 Now t he sodi um a lumina . .
t e solu tion is dil .
~ ated With wato r It rooultB In productio • ium Hyd roxid e.
N Al ' n of Alum in
a o, + '.2Nao 11- NaOH t Al(OH) 3
The precipit ate of Al(OH) is fi l
(con e)
3 1 tere d Wash d d
' e , rl<.Jci and hooted at lOOO "C to .
2Al(OH) _ ,ooo"c give pure alumina.
• Electrolyt.ic Red uct ion of Alurni " -> Al?O 3 + 3H?O
.
aluminiu m oxid e is calle d Hall H na.l'
.he elec troly
. .
In t his, the inne r-ca rbon lining oferou t s process. tic process fo r the extra ction of pure alum inium from
th ll
serves as a node . e ce serves as cat hode and t he block of
carbon dipp ed in electrolyte
The elect roly te dect roly te is kept at
a •
volta ge is used to avoid deco m 450 •
•
.. C by electrical heating and the voltage
position of the rnolten cryo adJu sted 5- 6 volts . A low
lite.
Reactions
Cryolite: Na3AlP- s ~ 3Na+ + Al+3
+ SP--
Fluorspar: CaF2 ~ Ca+ 2 + 2P--

Alumina: Al2O3 ~ 2Al+ 3 + 30-2

Posit0-2.
ive ions form ed in the solu tion are Na+,
F2, ca+ 2 and Al+ 3 while negative ions form
ed in the solu tion are
Cathode: .Inne r carb on living of the elec
troly te cell.
4Al+ 3 + 12e- -
4Al
Anode: Thick rods of grap hite are susp ende
d into the fluid electrolyte:
so-2 -12 e- -
6lOl
30 + 30 -30 2
Anode is oxidised to carb on monoxid
e, which furth er form s carb on dioxide.
2C+ O2 -2C O
2CO + 0 2 - 2CO2
Further puri ficat ion can be don e by elect
rolysis.

Flow chart of extraction of Aluminium

\ Ore-Bauxite Al2O3. 2H2O \
I
\ Con cent ratio n by NaOH to obta in Al2O
3 _\
I
Al2O3.2H 2O + 2NaOH 4
l o- isooc 2NaAlO2 + 3H2O
500
NaAlO 2 + 2H2O c , NaOH + Al(OHhl-
1000°c
2Al(OHh - - - Al2O3 + 3H20 \
I
Electrolytic Reduction of Alumina
Elec troly te: Alumina cryolite, Fluorspa
r (1 : 3: 1)
Cath ode - 4Al+3 + 12e- - 4Al
Anode - 60- 2 - 12e- - 30 2
C + o2 - CO 2
I --,
Puri fi ca t ion by e lectrolys is
Ca tho de: Ali 'l + 3e - Al
'J
Ano de: Al 3e - Al~

Me tall urgy JrI! 38 9

t::D
 Pure
Aluminu!_I_Jm~JS~::;.;;/,~ :,f;dJrj/,7/i~

Molten

Flu;l/1J
delllrsd~~ =:;:_;-~;.:=~-=:-, ,;:;:,.,~-=~._.-;.=--T-
~½:;;-:.~--:.

Iron Container

Example 11. What is the role of cryolite?

0 C nd enhances conductivity.
Ans. It lowers the fusion temperature from 2050°C to 95 0 a

Example 12. What is the role of powdered coke?

Ans. It is sprinkled over the surface of the electrolytic mixture. It:
0) Reduces heat loss by radiation
(ii) Prevents the bu ring of anode

Example 13. Which impurities are present in Bauxite?

Ans. Sand, Ferric, oxide· and Titanium oxide are present in Bauxite.

Example 14. What is Red mud?

Ans. Bauxite dissolves and forms sodium meta aluminate because of the amphoteric nature of aluminium
leaving behind insoluble impurities called red mud.

01csE Suggestions
- Go through various methods involved in the concentration ores.
- Practice chemical reactions of acids with metals and non metals under different conditions.
- Practice answering observation based questions.
- Ensure all aspects of the syllabus are covered and avoid selective study of topics.

( OBJECTIVE Type Questions )

Multiple Choice Question [ 1 mark] 3. Bauxite is ............... in nature.
(Strictly for ICSE Semester II Exams)
(a) Acidic (b) Basis
1. A chemical substance which is added with (c) Neutral Salt (d) Amphoteric
the charge to remove gangue in form of Ans. (d) Amphoteric
fusbsble slag is called.
Explanation: The oxide of Aluminium behave as
(a) Flux (b) Stag
acid and well as base. Hence it is amphotaric in
(c) Gangue (d) Both (a) & (c) nat11re.
Ans. (a) Flux
Explanation: Flux is added to remove gangue 4. The purification of Bauxite is done by:
beca use f lux is a chemical for cleaning, flowing (a) Calcination (b) Roasting
or purifying. (c) Smelting (d) Hall's Process
Ans. (d) Hall's Process
2. The main ore used for ext raction of iron is:
Explanation: Hall's process is used for refining
(a) Calamine (b) Bauxite
of bauxite to extract the metal. Bauxite contains
(c) Haematite (d) Cryolite
about 60% Al2O3, the rest being sand, ferric
Ans. (c) Haematite
oxide and titanium oxide.
Explanation: The fo rmula of Red Haematite is
Fe 2O3. The ot her ore of iron is brown haematite 5 • Cryolite ............... the
electrical conductivity of
(2Fe2O3.3H2O). electrolyte.

390 EJ!, Fdu r 'art ICSE Chemistry Class X

 (a) Decreas es (b) Increas es
(C) Remains sam e (d) 11\.1
tb) Incre ases ,,on e of th
t,.r,S, \' • • .
ese
e,cplanat1on . Cry ollte is us d {Ma rking Sch eme]
. . h
for bauxite in t e elec trolyt'e as a s l
Aluminium a nd thu s, incr eas ettp rod o ven t
\
uctlon of
' s con duc tion
~ Wh at Examiners say I

6• ............... met al is use d for making foils. ·

.,. Mqjorlty of candldate o wro te the
corre ct optio n but
(a) Carbon som e recalled ic Incorrect ly ao Bauxite.
(b) Aluminium
(c) Zinc (d) Nitroge n 12. Hea ting an ore In a limi ted sup ply
of air or
r,s. (b) Aluminium in the absence of air at a temperatur
e just
below its melting point is know n a$:
: Alum1· rnum
f>.
explanation ' ·
is used to mak e foil (a) Smelting
due to its mal leab le natu re.
(b) Ore dressing
7. By diss olving alum iniu m oxide
in cryo l' (c) Calcination
. .
............... solut1on 1s 1te
pro duc ed. (d) Bessemerisation llCSE 20141
(a) Conducting (b) Non -con duc ting Ans . (c) Calc inat ion
(c) Semi-co ndu ctin g (d) Non e of Explanation: Calcination is the
the se ther mal
t,.ns. (a) Con duc ting trea tme nt in pres enc e of ai r app lied
to met als
to achieve war m dete rior atio n of t he
a. An example of hyd rate d ore is .......
........ . part s. It occurs at the tem pera ture s
unst able
(a) Cryolite below the
(b) Bauxite melting tem pera ture of ores . Thu s,
hea ting a n
(c) Zinc Blen de (d) Gat ina ore in a limited supp ly of air or in the
abs enc e
f,.ns. (b) Bauxite of air at a tem pea rtur e just belo w
its melting
poin t is known as calcination.
Explanation: Bauxite is chie f ore of
Aluminium
having form ula Al203. 2H 0
2
9. The met al whi ch is fou nd abu nda ntly \Marking Scheme1
in the
earth's crus t is ............... .
(a) Sodium (b) Ma gne sium g;J What Examiners say
(c) Aluminium (d) Non e of the se -+ The term referred to was
eith er sme lting or
AAS. (c) Alum iniu m bess eme risat ion.
Explanation: Alu min ium is abu nda ntly
foun d in 13. The reas on for using alum inium in the
earth's crust. It was disc ove red by allo y
Oer sted in duralumin is:
1825 . It is highly reac tive met al,
so doe s not (a) Aluminium is brittle.
occur in free stat e.
(b) Aluminium gives strength.
10. Name a met al whi ch is a goo d con duc (c) Aluminium brings lightne ss.
tor of
both hea t and elec tric ity. (d) Aluminium low ers melting
poin t.
{a) Aluminium {b) Chlorine {\CSE 201 81
(c) Carbon Ans. (c) Alum iniu m brin gs lightnes
{d) Sodium s
/.J\s. (a) Aluminium Explanation: Duralumin is a n allo y of
aluminium.
Explanation: Alu min ium is a met al cop per, mag nesi um and man gan ese.
hav ing Aluminiu m
thre e elec tron s in out erm ost she is sele cted as maj or component of
ll whi ch can dura lumin
easily move .on giving cha rge. alloy bec ause it brings lightness. Dur
alumin is
used in alrcraft bec ause of its lightnes
1L· in.._
• r1e ma,• n ore use d
s.
for the extracti•on o f ·iron
i£":
C or Aluminiu m brin gs ligh tnes s
(a) Haematite (b) Calamine tMor\dng Scheme}
(c) Bauxite (d) Cry olit e
Aria
· (a) Hae mat ite (Fe O )
(ICSE 201 4] k7J What Examiners say
2 3 • A fe w cand idat es mad e the erro r of
Explanation : Hae m atit e is t h e ore of s_etecting the
Iro n. It Is option Aluminium is br1tt le. Most cand
an oxide of iron (fer ric oxid e). Ferr idate s chos e
ic oxid e in the correct option.
th e Haematite
ore is reduce d usin g car bon
and carbon monoxid e. ,& Caution
·1· .
• Fam, ,aris e w i'th t he rote of each meta l L1sed in on
Fe20 3 + 3C(s) >1073K 2Fe (s) + 3C0 tg) alto y.

JtI.::)
Me tal lur gy t:i'. !_. 391
 ues
SUBJECTIVE Type Q tions
fusible product formed when flux
he
23• Twith
Fill in The Blanks [ 1 m ark] gangue ,is ca lled ............... . rea~.
·~
14. The metal other than Aluminium presen t Ans. Slag
both in Magnatium and Duralumin is ............... Explanation: To remove the gangue, certa·
substances called slag are mixed With t~:
Ans. Magnesium (Mg)
concent reted ore.
Explanation: Duralumin is an alloy of
Aluminium made up of 90 - 94%. Al, 4% copper,
24• The most common ore of iron is ...............
1% mages ium and .5 to 1% manga nese while (calamine/hoernati~)
in manga tium 5% magnesium and 95%. Al is
[ICSE 2018]
present Ans. Haematite
15. - - - is the process of extracting pure Haematite
metal from its ore by physical or chemical
means. [Marking Scherne]
Ans. Metallu rgy
Explanation: The act and science of extracting
'wJ What Examiners say
metals from their ores is termed as metallurgy. ~ This question was attemp ted well by most
candidates,
16. ___ process is used to concentrate
Aluminium ore.
25. An alloy used to make statues is ............... .
Ans. Baeyer 's (bronze, brass, fuse metaQ
Explanation: In extraction of Aluminium, [ICSE 2020]
chemical process leaching is used for Ans. An alloy used to make statue s is bronze.
concentration of ore. The leaching is termed
as Bayer's process. True / False [ 1 mark]
17. Fluorspar increase the mobility of ions in flux 26. Haematite is one ore of Aluminium
because it act as _ __ Ans. False
Ans. Solvent Explanation: Hematite is an ore of Iron; Fe 0
2 3
Explanation: Fluorspar increase the Red Haematite (Fe 2O3) and Brown Haematite
conductivity and work as a solvent (2Fe2O3.3H2O) are ores of iron.
18. The chief ore of Aluminium is ___ . 27• Gangue is a substance used for oxidation of
Ans. Bauxite Aluminium.
Explanation: Bauxite is used as chief ore of Ans. False
Aluminium.
Explanation:
19. Alloy is a ___ mixture. Gangue is unwanted earth impurities present
Ans. Homogenous in ore.
Explanation: Alloy is a homogenous mixture, 28. Alloy is a homogenous mixture
fo rmed by two or more than two solids. Ans. True
20. Pure aluminium oxide is disolved in ............... Explanation:
to make a conducting solution. An Alloy is a homogenous mixture of two or
Ans. CryoLite more metals or of one or more metals with
Explanation: The cryolite work as a solvent certain non-metallic elements.
and reduces some of the energy costs involved 29
in extracting Aluminium by allowing the ions • Bauxite is amphoteric in nature.
Ans. True
is aluminium oxide to move free ly at lower
temperature. Explanation:
Oxide of Aluminium work as acid and base
21. Calam ine is the chief ore of ............... . both.
Ans. Zinc
30. leachi n ·
9 is used for concen tration of su lPh'de
1
22. The unwanted earthy impurities. accociated ores.
with ore is called ............... . Ans. False
Ans. Gangu e or Mat rix Explanation:
Leaching i
s use d for amphoteric ores.

392 Cl!J Edu c'a rt ICSE Chem istry Class X

t-4atch the Fol low ing Q
[ 1 rn ark] Ues tion s
--Co\um
--n_ (A)-- -. Ana.

,i. 1- -- -- --
(A) Zinc Blend e (i)
----
Cob,1"'" (B)
Feco 3
Column I
(A) Dural umln
Column II
(Ill) Ai rcraft body
(B) Cryolite (ii) Mgco (B) Solde r
0)
''C) Magn estite
n, KA.ls; o
(i ..) 3
(C) Brass
Electr ical fu se
(D)Felds pa r (iv) Zns 3 a (Iv) Decor ative articl es
(E) Siderit e ( ) (D) St ainles s Steel (Ii) Surgi cal
- - - - - ---l_ :_v, Na3AIF 6
~.r,s. (A)-~v), (B)-(v), (C)-(ii), (D) - (iii), (E)-(i)
--- --- --- instru ments
Dural umin~C o.r Afrcrcift body. ,
Explanation: (A) Zinc blend e (Zn .
Sold.e r: A o·~ Electrical fuse
Zinc. s) is an ore of Bross: D,or DE!,c~rcitive articles
(8) Cryol ite No 3 AlF 6 is an f . Stainl e~s Steel:·lf ? r surgi"c al instru m ents
. . O
re o Alum inium ·,
(C) M agnet1te 1s an ore of M .
agnes1um · til , , ·, · , , [Marking Schem e)
(D) Feldspar is an ore of alu""' . . r'V- Wha t Exam iners say
,,,1nium.
(E) Sidrite Ferrous carbo nate (F C .
. -. Tiome ~andi dates misma tched Colum n I
e 03) is an ore and Colum n
of iron. ' as t ey were not sure of the uses of aLLoys
.

Ver y Sho rt Ans wer Typ e Que stio ns

32, Colum n (~: Column
, (8) ; :' ,
~
: (:A ~ l~u-m- i~n.::...::..:::.__:4
:-:)-::D:--u-ra ) ~ M = e:.=:
ta: l~M
:_.~ir~r:i~k
[ 1 mark 1
:..:..:
(i:... ; sj-,~ ~.
34. Nam e two ores from wh'1ch •·
I (B) Mag naliu m (ii) CaF a1. u minium is
2 extra cted by electrolysis.
' (C) Balu xite (iii) Fe2 0 Ans. Bauxite (Al203.2H 20) and Cryolite lNa ALh
I
3 3
(D) Fluor spar (iv) Ore of Alum inium 35. Nam e the meta ls which · can be extracted
(E) Haem atite from the follow ing ores.
(v) Pressure Cook er
(A) Haem atite (B) Zinc Blend e
Ans. (A)-(v), (8)-(i) , (C)-(iv), (O)-(ii), (E) (C) Iron Pyrites
-(iii) (D) Calamine
Expla natio n: (A) Dura lumin is an alloy of Ans. (A) Iron (8) Zinc
Al(95%), Cu(4%), Mg(0 .5%) and Mn(0.5%). (C) Iron (D) Zinc
It is
used for maki ng press ure cooker.
36. Nam e an ore of iron whic h is sulphide.
(8) Bauxite (Al20 3.2H 2O) is an ore of Alum inium Ans. Iron Pyrite, FeS 2
.
(q Fluor spar is the mine ral form of calciu m 37. Nam e the chem ical name of cryoUte
fluoride CaF 2. Ans. Sodium Aluminium fluoride (Na AlF:i)
3
(0) Haem atite (Fe 0 ) is calle d Re_d Haem atite, 38. Fluorspar is adde d to pure Alumina. Expla in
2 3
w hich is an ore of iron. why.
Ans. Fluorspar increases the mobi lity of ions in
(E) MagnaLium is an alloy of (90 - 95%) Al and flour
as it act as a solvent.
(10 - 5%) mg.
39. Name the alloy of Aluminium whic h is
33• Match the alloys given in colum stron ger than it, light and is used is making
n I to the uses

____
given in colum n II. light tools.
Ans. Dura lumin
Column I Colu mn II _,
40. Name the meta l present in cryolite other
' (A) Dura lumi n (I) Elec trica l fuse than aluminlum and can be extracted by
electrolysis.
L(B) Solde r (ii) Surg ical instr ume nt
Ans. Sodiu m
\-; Brass (iii) Airc raft body _ 41. Why aluminium powder is used in thermic
... (D2 ~tain less Stee l (iv) Deco rative articles welding 7
[ICSE 2019 ] Ans. Sodium Hydroxide (NaOH)

Met allu rgy ~

f _lI!_ 393
 42. Name the solution used to reac t with Baux The sub stan ce pre pare d by addi
55• n

-~~-
ite met als to a base met al in appg
as a first step in obta inin g pure alum
inium . <>th,,
roprj
oxide in Baeyer's Process. roportions to o btam certain d . ~
P
Ans. It is a strong reducing agent
.
propert ies. llcse l "
Ans. Allo y 0201
43. Nam e the impurities left behind afte
r t he
conc entr atio n of ore. Give Reasons
Ans. Gangue
[ 1mark]
56 Why Bauxite is hea ted first durin
44. Nd'm e • extraction of Aluminium? 9
the scie ntis t who discovered the
Aluminiu m. Ans. Bauxite is heated first duri~g ~he
extraction
• Alum inium to remove volatile impu
Ans. Oersted in 1825. rities. of
45. Give the constituents of Bauxite. 57. Why Aluminium oxide is a very
stab!@
Ans. Bauxite contains 60% Al O , rest compound?
2 3 being sand, Ans. Aluminium oxide due to its grea
ferric oxide and titanium oxide. t attent for
oxygen is a very stable compound.
46. Nam e the compound formed when
Bauxite
dissolves with NaOH. 58. Why elec trol ytic reduction is chos
en fi
• •
Ans. Sodium meta aluminate (NaAlO reducing alum iniu m.? or
2). Ans. AL2 o3 is a very stable compound.
47 • Nam e the process used for electroly Hence it can't
tic be reduced easily by com mon redu
reduction of fused alumina. cing agent
and elec troly tic reduction is chosen
as method
Ans. Hall Heroult's process. for reducing alum inium.
48. At which temperature the molten electroly 59. Why it is not easy to carry elect
te rolytic
is heated in Hall-Heroult's process. reduction 2050°C?
Ans. 950°C by electrical heating.
Ans. It is not easy to carry electroly
tic reduction at
49. Write the Formula of Fluorspar. 2050°C because at this Alumina gets
vaporises.
Ans. CaF2
60. During elec trol ytic reduction, why is
the tank
SO. Give the composition of Duralumin. bott om mad e in slop py way ?
Ans. Duralumin Composition: Ans. To facilitate the removal of
the molten
95% Al 4% Cu, .5% Mg, .5% Mn aluminium.

51. Which alloy of Aluminium is used in mak 61. Why is the cryoUte add ed in Hall Hero
ing ult's
household appUances? process?
Ans. (1) It lowers the fusion temp
Ans. Magnalium erature from
2050°C to 950°C and enhances cand
uctio n.
52. Name the alloy used for making pres (2) It increases its conductivity since
sure pure
cooker. alumina is almo st a non-conducto
Ans. Duralumin r of
electricity.
53. Nam e the scie ntist who devoloped 62. Give Reason why fluorspar is adde
the d i"
proc ess of extr actio n of Aluminium. electrolysis of alunimium.
Ans. HaU and Heroult (1885) Ans. (1) It act as a solvent for electroly
tic mixture.
54. The process by which cert ain ores, spec (2) Increases the conductivity since
ially pure
carb ona tes are conv erte d to oxide alumina is almo st a non-conducto
in the r of
abse nce of air. [ICSE 2019] electricity.
Ans. Calcination 63 • Why is the Pow
dered coke sprinkled over 1

Calcination surface of electrolytic mix ture ?

Ans. (l) TO reduce hea t loss by radia
[Marking Scheme] tions.
(2) Prevents burning of anode.
'wJ What Examiners say 64 Wh
• Y are carb on ano des replaced from ·rtie
"- Most candidates mentioned the proce to time ? ti ll
ss correctly.
However, a few candidates confused it with
roasting. Ans. Carbon anodes are replaced from
time to tirl'le
because th ey get oxidised to CO .
0 2
39 4 rrrr_ EduL,-Jart ICS h
,__ .
EC
1
·;
, I'
\,I
,1
1: Wh!:I is so muc h graphite req .
66• (Hall Heroullt's) process? l.ured Electrolytic
Short Answer-I Type Questions
Much graphite is reuqired fi
Ans, process because it react With ; r electrolytic [2 marks ] I
anode column. 2 Produced at 74• state the main components of the following
l. alloys:
\ ve salanced Chemical Equ . (A) Brass
:1 01 [ 1 mark] at1ons
l
(B) Duralumln [ICSE 2018, 14]
:, : water is added to sodium al . Ans. (A) Brass: Copper and Zinc
66• heated• um1nate and
(B) Durnalumin: Aluminum Magnesium,
Ans, NaAl02 + 2H20 ~ NaOH + Al(OH)J Manganese and Copper •
~
v1• sodium hydroxide is added to Ba ux1te.
. Copper, zinc
,.Ans. Al203.2H20 + 2Na0H ~ 2NaALO 2 + 3H 2 o
Baluminium, copper
Copper, tin
68. Aluminium hydroxide is heated at 1OOO0c
[Marking Scheme]
heat
Ans. 2Al(OH)3 1OOO0c Al203 + 3H20 ~ What Examiners say
X/-
-. lnS t ead of th e main components, all the metals that
69, Decomposition of Cryolite form .th e alloys were written by a large number of
An> Na 3AlFs ~ 3Na+ + AL+ 3 + 6P- ca nd'dates. Others wrote incorrect combinations.
Probably many resorted to guess work.

70, Decomposition of Fluorspar 7 5• From the list of terms given, choose the
most appropriate term to match the given
Aris, CaF2 ~ Ca+ 2 + 2P-
description.
(calcination, roasting, pulverisation, smelting)
71. Decomposition of Alumina.
(A) Crushing of the ore into a fine powder.
Ans. Al203 ~ 2Al+ 3 + 30-2
(B) Heating of the ore in the absence of air
to a high temperature. [ICSE 2017]
n, Addition of excess ammonium hydroxide into Ans. (A) Pulverisation
copper sulphate solution. [ICSE 2019]
(8) Calcination
AAS. When excess ammonium hydroxide is added to
copper sulphate solution, a pale blue precipitate ¾' I:,.,,'<,,\,_

h,iQI') ,, ', ,
is obtained which dissolves forming deep blue "n . "',.'\-" . ,
't,~' ,,.. ',;;_: ' '
solution.
:,,,."', ~ ~~r~a..i..-..- c..&......-.....1
,,,,:~.:\~":S"'
Chemical Equation: "'¾,~~' -'~~ ,,, . ~ " ' ' ~ ■---.
< · ~ --~

CuS04 + 2NH 40H ~ Cu(OH)i + (NH 4h ~] What Examiners say

S04 + 4H20 '-+ Most of the candidates answered part A correctly, In
Cu(OHh + (NH4)2 S04 + 2NH40H part B, a small fraction of candfdates got confused
~ [Cu(NH3)4]S04 + H20 between roasting and calcination as they focused on
?. _J 11 :1£~ -,,;,fff!lfl-1-~~, ~111 'ifR -~
the high temperature mentioned in the question.
The ri'Prd 'Solution,;7fjt~ : mf$1:'.{ h\ · ' 76. Why aluminium sheets are used on roof top?
pr~pitate is- ng~j~j~~ ~e !,. ·,~! if1I'~ '
supported N rrword-
.-• '- s~- ar
:- :,w,;e.
bu-:,,,-,J' :~al.ve. Ans. Aluminium sheets are used on roof top because
so~b•- ~ , ._ ·,~ -?, %_
of the heat falling on the roof is reflected and
, 1-t:. :}!0':,- \c '\ '", -
,: ·v:Xi ·:;;
t;,,
_,, _,;,-",1[M,rlclri9,,Set,e,rn•l
,.\t 4:<f • :,
as a result interior remain cool.
'lj.l w
<{,//~·./ ,,

,,
',,/ . ,,,

,, 77. Why aluminium is used in f\ash bulbs?

~ hat Examiners say Ans. Due to its property to emit white light
Some
bl can d'dt ates did not write the solubility of the
aluminium powder is used in flash light bulbs
s ue ?recipitate in excess of ammonium hydroxide
s01ut,on·• instead of writing deep or inky blue so lut1on
· for indoor photography.
ome Wrote "deep blue precipitate is formed''.
73 78. What Is an ore?
• at
Write th e equation
. for the reaction
. that accur Ans. The naturally occuring mineral from which
th0
el ca de during extraction of aluminium by metal can be conveniently and cheaply
~ ectrolysis. extracted is known as the ore.
s. Cath
ode: Alr3 + 3e- ~ Al. 0

Metallurgy JfI! 395

t:m
79. In construction work, state why t he 83. Fill in the bla nks in following list .
alloy Duralumin is used rather than pure common Chemical
aluminium? name name
Ans. Du ra lumin is used rat he r t ha n pu re a luminium
beca use duralumin is harder, strong er a nd more
resista nt to corrosion t han alum in ium.
(A) Cryollte
(B) I Calcium Oxide

80. "Aluminium can't be extracted by the Ans. (A) Cryolits Sodium l'
Aluminiu m
reduction of its ores by carbon." Explain
briefly. Fluoride
Ans. Aluminium is a highly electropositive metal. Its
(8) Q~i ck lime Calcium oxid e Cao s"~.
..,j~efS ioflol ,rl
o re is a m photeric in nat ure a nd is highly stable. 84. Define (A) electro metallurgy 1.(0". ccos d t
'~ eo ere
Moreover, ca rbon immediately combine with (B) electrorefining .,. 11' o~ st/V ~uors
Aluminium to yield Aluminium carbide (Al 4 C3) Ans. (A) The process of extraction of metal fr /, ./,p usri~g . gof
. Orn 1- •,/ ..· ,,,rJ1 towe(lfl rot
ore b y th e use of e le ct nc current. is ele ·· ; : >,rrl1e (!le( W
81. Explain why it is preferable to use a number metallurgy. ttJ,, / ; . es e1 the
of graphite electrodes as anode instead of ,. .,,.::1 ((le or
(8) The process of refining of impure . .,, ,ArO
single electrode during electrolysis. . rncr.a -/ ~ f the
by use of electric current. is called el · . 0
Ans. It is preferable to use a number of graphite ec-u-r
refining. · . r eocl1 thE
. -: descn
·oe .
electrodes during electrolysis because anode
85. Name the following metals: •,\o'II, f ol\Jl'Yll
gets oxidised by the oxygen evolved. Hence, if ·,~JO(tiOfl 0
large number of electrodes are used it will keep (A) A metal present in cryolite other than ~- lite
sodium. l)CfYO
the process continuous for long time. • . hydroJC
(8) A metal which is unaffected by dilute or !) 10d1Urfl
Short Answer-II Type Questions concentrated acids. llGraphite
[ 3 marks] (C) A metal present in period 3, group 1 of : :1oiaint why:
the periodic table. [ICSE 2012] · \i ln the electrol~
82. Jn order to obtain aluminium, the following Ans. (A) Aluminium (Cryolite ~ Na 3 AlF 6) Hall Herol
inputs are required: Bauxite, Sodium,
(8) Platinum electrolyte
hydroxide and graphite. The aluminium
compound in bauxite is aluminium bauxite
(C) Sodium powdered co
and the main impurity is iron (Ill) oxide. 86. The following questions are relevant to the :, \ron Sheets ar
Aluminium is obtained by the electrolysis of extraction of aluminium: galvanizatio
aluminium oxide dissolved in cryolite. (A) State the reason for addition of caustic · '.' Cryolite: II
{A) When Bauxite is treated with sodium alkali to b~uxite ore during purification of
hydroxide solution what happens to bauxite.
(8) Give a balanced chemical equation for
(1) Aluminium oxide.
the above reaction.
(2) Iron (Ill oxide) (C) Along with cryolite and alumina, another
(B) Name the process used for the substance is added to the electrolyte
purification of bauxite. mixture. Name the substance and give
(C) Write the equation for action of heat on one reason for the addition. [!CSE 20121
aluminium oxide. Ans. (A) Bauxite dissolves in caustic alkali and tt,,.,:
(D ) Write the formula of cryolite. impurities can be separated and ol:;0 t-'
Ans. (A) (1) Alumi nium oxid e dissolves in NaOH obtain a solution of Sodium Aluminate.
solution to fo rm sodium met a aluminate. (8) Al2O3.2H2O + 2 NaOH ~ 2NaAl0 2 + 3H:O
Cl " 0
(2) The iron (Ill) ox ide re m a ins una ffected in (C) Fluorspar (CaF 2). This substance act ' "
s odium. solve nt and it increases conductivity, it also
(B) Bayer's Process reduces t he melting point of Alumina.

(C) 2Al(OH), _6. ➔ Al2O3 + 3 H2O 87 • Name the following:

(A) The property possessed by n,etals bY
which they can be beaten into sheets.

396 Cl:!, Edu C:a rt ICSE Chemistry Class X

 the
(0) A compound added to lower the fusion d to reduce the
temperature of electrolytic bath 1 1. Cryolite is use melt
. f l . . n the temperature to increase the
extraction o a um1mum.
(purified ore) I to a solvent.
(C) The ore of zinc containing its sulphide. conductivity / it _actS as . used to
[ICSE 2014] 2. Sodium hydroxide or NaOH ,s te the
A) Malleability dissolve bauxite / t~ con~~ntra . et
Ar,S, (
(0) Cryolite ore /insoluble ,mpunties g.
recipitated or removed/ NaOH rs
(C) Zinc Blende (ZnS) P , ·d - or
used to dissolve aluminium OXI e
Malleability Al2o3 / to convert bauxite to sodium
Cryolite or Na3 Al F6 aluminate / to purify bauxite.
Zinc blende 3. Graphite lining of the electrolytic
[Marking Scheme] tank is used as cathode/ graphite rods
are used as anode.
WJ What Examiners s~y 1. Coke powder does not qllow the
,.. Ductility was the occas10nal incorrect answer. radiation of heat from the
,.. Most candidates answered this part correctly with electrolyte / prevents oxidation or
0 few of them listing fluorspar as the substance
burning of the anode./ prevents loss
responsible for the lowering ofthe fusion temperature. of heat.
,.. Some candidates either wrote the chemical formula 2. Zinc is more reactive than iron ./ zinc
or its chemical name or the wrong name of the ore. is more electropositive than iron / Zinc
is higher in the activity series / to
88, (A) For each of the substance listed
prevent rusting / corrosion.
below, describe the role played in the
. , , .. ,, .... . [Marking Schemel
extraction of aluminium:
(1) Cryolite
(2) Sodium hydroxide
'W-J. What Examiners say
~ (A) Errors such as solvent for bauxite.
(3) Graphite Incorrect answer of dissolving alumina instead of
(B) Explaint why: bauxite.
(1) In the electrolysis of alumina using the Most candidates answered correctly.
~ (B) Most candidates answered this part correctly.
Hall Heroult's process • the
~ (C) Few made an error of stating Zn lies below Fe in
electrolyte is covered with the activity series.
powdered coke.
(2) Iron Sheets are coated with zinc during
& Caution
~ Students to be reminded to learn to be specific and
galvanization. [ICSE 2015] . focus on the choice of correct chemicals when there
Ans. (A) (1) Cryolite: It lowers the fusion are similar ones to choose from. For eg alumina and
bauxite.
temperature from 2050°C to 950°C
-+ Knowledge of the correct order of metals in the
and enhances conductivity. activity series is essential.
(2) Sodium Hydroxide: It is used to remove
the insoluble impurities from the ore. 89. (A) Name the most common ore of the
metal aluminium from which the metal
When Bauxite ore is made to react
is extracted. Write the chemical formula
with Na OH it forms Sodium aluminate
of the ore.
leaving behind impurities called Red
Mud because it contain Fe2O3 and (B) Name the process by which impure ore
sand. of aluminium gets purified by using
(3) Graphite: It is used as an (Cathode concentrated solution of an alkali.
electrode in the process of (C) Write the equation for the formation of
electrolysis as it has a very high aluminium at the cathode during the
melting point and a good conductor electrolysis of alumina. [ICSE 2018]
of electricity. Ans. (A) Bauxite
(B) (1) Powdered coke does not allow Chemical Formula:
oxidat ion or burning of t he Anode, it
Al2O3: 2H 2O
also prevents loss of heat.
(B) Baeyer's Process
(2) Zinc is used in galvanising as it prevents
rusting being more rea ctive than iron. (C) Cathode Al3+ + 3e- ~ Al

Metallurgy /;jj, 397

 Bauxite Al203. 2H20
(C) Name the electrode, fro
aluminium is collected. [~ ~I
J
Boeyer's Process , An•• (A) Cryolite is mixed with alumina ~ ~ ~
Al3+ + 3e ➔ Al the fusion temperature of the rn· o~
[Marking Sch•m•l a • 0
2oso c to 950 C and increase ixture fr
its o,i:
.. elect .
conduct1v1ty.
~ What Examiners say rieo1

• Most candidates wrote the name of the common

(B) A layer of powdered coke is sprinkled
ore of alumi11um from which the metal is extracted the top of the electrolyte to red 0ver
as alumina or cryolite instead of Bauxite. Some heat loss from the electrolyte by r uee. t~" e 1

candidat es gave chemical formula of Bauxite as Od1otio

Al2O3.SHO wherein the number of water molecules (C) Aluminium is collected from cathod n.
was incorrect.
e.
• A few candidates named the process by which
t.t1·~. :,Cry~lite'fe~;.. . ,· lit{~-,
,.. ,,,. . ,,,,,Jrt.,·/f. ,ft , ;O)Peroture
impure ore of aluminum gets purified by using 'l;/$ '1)",fofth(f 'rYlf .,
%,,;::://,,.:,:, . •/,f/!f/ t i_i.l / .
,,
l"'t;re:
/1 _oses H,. _
concentrated solution of an alkali as Hall's process f ' ;:; :,mpb'1lrty· j(>J:/ , :incre
or Hoope's Process in place of Baeyer's process.
f;,t;,1;"!/,;';,,(1/?-b / #//4 ✓.
(' , •
"le
Oses
the
v;:,/:, · ~1'~~~~~'.Y)}1- · '~~ Y,te,J Acts as
• (8) Most candidates wrote the correct equation for
the formation of aluminum at the cathode
;~9lt ept £, , . ;<. / ,
.i O . , f lt ',,f < •E:!ctS J< th
during the electrolysis of alumina. However, a I/ 1· /,;,, '/ e graphitf;
few got confused and wrote equations like: ffr?,~ .·9~idation by
Al - 3e- Al3+ tp_;;~~o¢e I Powdered
..!,,' . )'df'heat
Or Al+ 3e- Al3+
:·, . from th
OJi~
Or 2Al3 + +6e- Al
e
,& Caution
• Clarify electrolysis and its applications in detail with
examples. Memorize the names and formulae of
important ores of metals (listed in the syllabus) and
the processes for extraction of metals from ores
wJ What Examiners say
• Most candidates answered this question correctly.
90. Give the chemical formula of: ,& Caution
(A) Bauxite • Discuss the questions based on the extraction of
(B) CryoUte aluminium from alumina by Hall-Heroult's process in
(C) Sodium aluminate. [ICSE 2019) class.
Ans. (A) Al203.2H20 92. Baeyer's process is used to concentrate
(8) Na3ALFs bauxite ore to alumina:
(C) NaAL02 Give balanced chemical equations for the
reaction taking place for its conversion from
bauxite to alumina. [ICSE 20201
150-200° C

~ What Examiners say 50-80°C

NaOH
• In writing the chemical formula of bauxite, many
candidates either wrote incorrect number of water +Al(OHl:
molecule s or did not write them at all.
In subparts (B) and (C), some candidates wrote
incorrect formulae.
93. {A) Give the commo n name of one ore fro!11
& Caution which alumin ium is extracte d.
-. Regularly practice through class tests, games, quizzes
to learn the details. - Understand metallurgy in detail. (B) Name the process of extraction.
(C) Name. one other metal which is extracted
91. Answer the fol.lowing question based on the
by this metal.
extraction of aluminium from alumina by
(D) Give the reason why aluminium can't ~
Hall-Heroult's Process:
obtaine d from aluminium oxide by bla
(A) What is the function of cryollte used along furnanc e process.
with alumina as the electrolyte? (ij Name .
(8) Why is powdered coke sprinkled on top (1) the propert y for which alum 1·n1·u111
15

of the electrolyte? used for cooking utensils.

0

398 ffi Edu~ ort ICSE Chem istry Cl ass X

 (2) The property for Wh" h
is used for overh1c alurniniurn
. . ead elect. Using the information above, complete the
transm1ss1ons. ric
following:
(F)
Aluminium is more active th . (A) _ _ _ is the metallic element.
. an iron and
, 1et there 1s no corrossion of l
:, (B) Metal atoms tend to have a maximum
when both are exposed to a. urniniu rn
air. Explain of ............... electrons .1n the outermost
why?
energy level.
(A) Bauxite
5 (C) Non-metallic elements tend to form
Af1 ' (S) Electrolysis
- - - oxides while metals tend to form
(C) Sodiu~ , ............... oxides.
(D) Aluminium can t be obtained by blast
furnance process because Aluminium h (D) Non-metallic elements tend to be ...............
. . ti as a conductors of heat and electricity.
strong a ff 1nity_ or oxygen and aluminium
produced at high temperature reacts Wit
•h (E) Metals tend to ............... electrons and act
.
coke to form Aluminium carbide. as ............... agents in their reactions with
(E) (1) Aluminium is unaffected by food elements and compounds.
acids and has low density and is good Ans. (A) y
conductor of heat. (B) Eight
(2) It is a good conductor of electricity and (C) Acidic, Basic
is cheaper and lighter than copper. (D) Very Poor
(F) Because of formation of thin, transparent (E) Lose, Reducing
protective, non porous adhering film of
95. The following is a sketch of an electrolytic
Al203 on its surfaces, Al is practically
cell used in the extraction of aluminium:
corrosion resistent to air as well as moisture.
While iron is corroded in most air, due to +
formation of porous, non-adhering layer of
rust (Fe203.2H20).

94. X y
Normal 2,8,7 2,8,2
Electronic
Configuration
Nature of Dissolves in Very low (A) What is the substance of which electrode
oxide water and solubility A and B are made?
turns blue in water. (B) At which electrode (A or B) is the
litmus red. Dissolves in
aluminium formed?
hydrochloric
acid. (C) What are the two aluminium compound
in the electrolyte C?
Tendency for Tends to Tends to act
oxidising and (D) Why is it necessary for electrode B to be
oxidise as a redu-
reducing elements cing agent. continuously replaced?
I reactions and com- Ans. (A) A and B are made of carbon.
pounds. A ---7 cathode ---7 gas carbon
Electrical and Very poor Good elec- B ---7 anode ---7 carbon rod.
Thermal electrical tricalcon- (8) AL is formed at cathode (A) in the molten
conductivity conductor ductor good state which state which can be taken out
poor thermal through as tapping role.
thermal conductor.
(C) Cryolite (Na3ALF)

- Tendency to
forn, alloys
conductiv-
ity.
No tend-
ency to
Forms alloys
Bauxite (AL203, 2H20)
(D) Oxygen is given off at anode where it reacts
with carbon to form CO. The hot CO further
and amal- burns to form CO 2. As a result, anode gets
form
Qams worn out and have to be replaced from
alloys. -- time to time.
[ICSE 2013]
0

JfI!_
Metallurgy &a 399
 (D) A Covalent oxide of a metalloid is SiQ
96. 2 as
Si is a meta lloid
Pura
Aluminu~m~.j!,,..,......-f"T"'M"ri--r-n--,,'-r-,"7"T",,-;-;-.,..,.
A basic oxide---- MgO
S02
Al20 3
S102
[Marking Schet'\'lt}
Iron Container
(A) Which of A 8t B is cathode and which one ~ What Examiners say
of anode? ..,. Alumina was used which was amphoteric and hen
(B) What is the electrolyte in the tank? could not be repeated in part (C). ce
(C) What material is used for the cathode? ..,. Few candidates selected the incorrect answer.
Ans. (A) A are graphite rods and they act as cathode ..,. Those who repeated the answer lost marks.
and 8 as anode. ..,. Candidates got confused between S02 and s;o
2
(B) Impure aluminium 98. (A) Name the solution used to react With
(C) Carbon Bauxite as a first step in obtaining
pure aluminum oxide, in the Baeyer's
97. Choose the most appropriate answer from process.
the following list of oxides which fit the (B) Write the equation for the reaction where
description. Each answer may be used only the aluminum oxide for the electrolytic
once: extraction of aluminum is obtained by
[SO2, SiO2, Al2O3, MgO, CO, Na2O] heating aluminum hydroxide.
(A) A basic oxide. (C) Name the compound added to pure
alumina to Lower the fusion temperature
(B) An oxide which dissolves in water forming
during the electrolytic reduction of
an acid. alumina.
(C) An amphoteric oxide. (D) Of the equation for the reaction that
(D) A covalent oxide of a metalloid. occurs at the cathode during the
[ICSE 2015] extraction of aluminum by electrolysis.
Ans. (A) A basic oxide: MgO
(E) Explain why it is prefereable to use a
number of graphite electrodes as anode
Explanation: instead of a single electrode, during the
MgO + 2HCl ~ MgCl2 + H20 above electrolysis. [ICSE 2016]
(B) An oxide which dissolves an water Ans. (A) Caustic Soda Solution (NaOH)
forming an acid is S02
Explanation:
(B) 2Al(OH)3 iooooc
Al203 + 3H20
(C) Cryolite + Fluorospar (Na 3AlF 6 + CaF-z)
S02 + H20 ~ H2S03
(D) Al3+ + 3e- ~ Al
(C) An amphoteric oxide
(Something that reacts with both Acid and (E) Graphite rod is used as anode and ~
gradually gets used up on its reaction
Base giving salt and H20) is Al203
with Oxygen forming Carbon monoxide
Explanation: and Carbon dioxide and hence needs to
Al 20 3 + 6HCl ~ 2AlCl3 + 3H20 be replaced periodically and thereby th e
Al 20 3 + 2Na0H ~ 2NaAl02 + H20 time span is increased.
 S tu dy o f
C om po un ds
·,-. - ,
'7""''_°(•· ~
;t}''i
, , ' , ,.,.. ' _,_ .; <

.. ,.. . . ,
-~~-- . "},
j,._.I

Y:J_-; .
-~~~- :~---- ._:.,
'~~;:.,
,.. "·

\r·~f

, a· -- __ am
Drugs like Hyd roxy chlo roqu ine (and mos t others) are mad
e using various
salts to easi ly diss olve in wate r with in our body. Carbonat
ed drinks give us
a refre shin g sens ation only due to carbonic acid in the
drink. which is crea ted
when carb on diox ide reac ts with water. Soap s contain
sodium hydroxide
(base) that serv es us the purp ose of sapo nific ation and
smo othn ess.

Ch apt er Topics
ii] Hydrogen Chlor ide
Ii! Amm onia

lil Nitric Acid

Ii] Sulphuric Acid

 HYDROGEN CHLORI[)~
,~,,
STRUCTURE
Physical appearance d liquid. The gaseous hydrogen chl .
The compound hydrogen chloride exist in two states 1·•e·• gaseous an °ride •
~.
converted into liquid form by a procedure.

Structure b ding. The compound is composed up of

Hydrogen chloride is a compound which . lar hydrogen on
possess po . . •fti ce between these elements is high. HtA,0
. . The electrone gat1v1ty d1 eren
elements i.e. Hydrogen and chlorine enee,
they possess partial Ionic character.
H(l) = 1
Cl(IH) = 2, 8, 7

••
..
or H : Cl : or H-Cl

Dot digaram or Lewis structure

Orbital diagram

~m~~~ Which type of Bonding is present in

HCl? ·
Ans. Polar covalent Bonding
The molecular formula of compound in HCl, having molecular mass
36.5
HCl = 1 + 35.5
HCl = 36.5

Example 2. Who gave the name "Muriatic Acid to hydrogen chloride?

11

Ans. Glauber (1648)

Discovery
• Hydrogen chloride gas was first prepared by Glauber in 1648 by heating
common salt with concentrated
sulphuric acid. It is also known as "Muriatic Acid". The term "Muriatic
acid was given by Lavoisier"
• Humphrey Davy in 1810 proved the gas to be a compound of Hydrog
en and chlorine.
Example 3. Calculate the molecular mass of HCl.
Ans. Molecular mass of HCl = (1 >< 1) + (1 x 35.5) = 36.S

402 lJ,;, Educ'art ICSE Chemistry Class X

 occurrence
• In natu re hyd rog e n chlo ride
. · . . Qas occ urs in .
, 1s also pres.ent in. ga~ tnc Juice, , , ,
free statt:l 1n volcanic ernmlsslon. Bes . , . .
ides this, in mammals ,t.
,r11tle 4. Which scie nt ist is rep
~o ~
,.,... Hum phrey Davy (1810) onsible for t h
e nome 'Hydro gen Chloride'?
orrtPl• s. What is the percentage of
~,,.,~
.... 2 to 4% in gastric juic e. It help
. s ind '
h
yd~ogen chlo
1gest1on. ride present in mammals? What
is its role .

LtoP1c2]
PREPARATION OF HYDROGEN
CHLORIDE GAS
BY Synthesis (Direct combinatio
n)
It is syn thes ised from its con stit
uen t elem t •
en s 1n presence of diffused sunligh
t
Hyd rog en + Ch lor ine ~ Hyd
rogen (Chloride)
(Moist)
gas
diffused
sunlight 2HCl(g)
&Caution
.. The reaction is explosive in dire
ct sun ligh t and it is negligible
in dark.
Laboratory Preparation
In labo rato ry, it is pre par ed by the
reac tion of Sodium Chloride and
con cen trat ed Sulphuric acid.
• Reactant used: Sod ium chlo ride
and con cen trat ed Sulphuric acid
• Conditions of the reaction: The
tem per atu re should be maintained
belo w 200°C.
Below
NaCl+ Cone. H2S04
200 °c NaHSO4 + HClt

2Na cl + Con e. H2S04 abo ve

200 °c
• Procedure: Take som e sod ium chlo
ride in a round bot tom flask and set- up the
app a ratus
Cone. sulphuric acid

Moist HCl gas Dry HClgas

Laboratory Preparation of HCl

gas
. eati ng the mixture gently, HCl gas
Pour con cen trat ed sulp hur ic acid Is evolved .
. On h
0

Hydrogen chloride JrI!_ 40 3

l::JrJ
 • Precau tions: (1) The rea ction mlxt uro should not be heate . d beyond 200°C

(2) Tho t hi~tlo i1u'ln ol m,1st bo dlppod In common oalt .

, . . h . h
• Collection: Dt u hydrogen gas Is collect ed by upward diop l em ent of a,r as 1t 1s eav1er t an air.
ac . 'd
Bofure t ho coll.ac tion, t he gos is drlod by pasoln g t hrough cent ra ted sulphu ri c ac1 .
con
~ Impo rtant
.
._ The other dGh!Jdratmg agents such as phosphorus pentao . ium oxides are not used as the hydrog f:n r h
x,de and ca 1c - lrin,J~
gas unde'tgoos chemical reactio n with these compounds

2P 2o 5 + 3HCl ~ POCl3 + 3HP0 3

Cao + 2HCl ~ CaCl2 + H20
• • H droxide solutio n. The gas jar is filli:d
lndent tfication: The gas is identified by using Ammo nium
Y .
.
hydrogen chloride gas, bring a glass rod dipped . · m hydrox ide near its mouth . If densE: 11, 'J
tn ammo rnu
N r -;,
fumes appea r immed iately, the gas jar is filled with hydrog
en chlorid e gas.
HCl + NH 40H ~ NH4Cl + H20

ITOPIC 3·1
PROPERTIES OF HYD ROG EN CHL ORI DE
Phys ical Prop ertie s
• Hydro gen chloride is a colourless gas having punge nt chokin
g smell.
• It is acidic in nature, Hence, it is sour in taste.
• It is heavier than air.
• When it is subjected to a high pressure at low tempe rature
, it is liquifie d to a colour less liquid.
• It is highly soluble in water.

Expe riment to Dem onst rate Density

HO gas is heavie r than air. It can be proved by pourin
g the gas in a jar with a burnin g candle. The candle ge:;
exting uished because HCl gas being heavier occupies the
lower portio n of the jar and forces the air out of it

Burning candle

Figure showi ng hydro gen chlori de gas · he ·

15 av1er t h an air
•

Foun tain Expe rime nt

• This experi m ent 11, do ne 1o 1,how t hat HCl g o & t& highl y solubl e.
• To perfor m the experim e nt, w i.: tu ku u drlJ rou nd bot torn1:Jd
fl ask fll d . h fch2
1 8 · with dry HCl
flas k. fix a rubb er tito pp er w it h t w o hul e:, l h,ou4 l 1on e gas On the rnout 0 .
hole pas l . ·
a dro pper with fe w drops of w ut1;:r IJut th e Jet tul> e in s O ong Jet tube and throug h other po le Pas,
the beak . . . p ess t11e
dropp er, as t he blu e lit mus enters th e Jet tu be w it h great · er contai ning bl l' lut1on. r
O fo fi . ue itmus so
rce, orm ing a red founta in .
0

404 l://2 Edu c'a rt ICSE Chem i stry Clai:;, y

 h. h
s due to ,g
k diss o lve ! '
r, HCl gos pre sen t in fla s she s the blu e litm us
s in t he flas k from t ho dro ppe
tis because as the wa t~r goe outside pre osu rc b ein g hig
her, pu
pressu re insi de. Tho
I tubilitY the reb y low erin g the
ube
so . n inside, thro ugh the jet t .
solut10
s red due to a cidi c nat ure of HCLgas..
btue litm us turn . .
1i,e dro ple ts of HC Laci d.
the high solu bilit y, HCL gas fum es in mo ist air form in g tiny
oue to

Red foun t ain

Dry HC lgas

Dro ppe r con t a in ing

J et tu be - - - • wat e r

Blu e litm us
solu tion
l gas
tra te ext rem e sol ubi lity of HC
Fou nta in exp eri me nt to dem ons

HY DR OC HL OR IC AC ID
ed w he n hyd rog en
ich is ver y stro ng in nat ure as it is a min era l acid. It is for m
Hydrochloric acid is an acid wh
wa ter.
chloride gas is diss olve d (pa sse d) in . It is pre par ed by dissolving Hq
ga s in wa te r. Th e
as hyd roc hlo ric acid
7heaqu eous solu tion of HCl gas
in kno wn ins abo ut 56% of
mo re gas is abs orb ed. The pro duct is con cen trat ed and con ta
gas is passed into wa ter until no
r:idroge n chloride by ma ss.
Procedure nel arr ang em ent . An inv erte d fun nel, con nect ed
to t he HQ
h the hel p of fun
• The gas is diss olve d in wa t er wit y tha t it jus t tou che s the wa ter tak
en in t he tro ug h.
in t he bea ker in suc h a wa urs and in tur n, t he
gas sup ply, is pla ced s up in the funnel, bac k s uctio n occ
e in wa ter, the wa ter rise wa ter.
' The HQ gas is hig hly sol ubl we n t he rim of the fu nne l a nd t he s urfa ce of
g a n a ir gap bet
level outside the fu nne l falls cre atin wh ich had rise n in t he fun nel fa
lls dow n
the n bec om es equ al and wa ter
• The pressure out sid e a nd ins ide
again. rm atio n of hyd roc hlo ric
wa te r in the tro ugh is sat ura t ed wit h HCl gas res ulti ng in fo
• This process contin ues , t he
acid.
Phys,·cat Properties
It is a colourle ss Liquid havi ng
pun gent a nd chokin g s m e ll.
•
• It is sour in tas te
' It is read 1 . wa ter.
·lYso luble 1n

Chern·ical Properties
y a cidi c
of Hy dro chl oric a cid is stro ngl
• Nature: The aqe uou s s olu tion
s on HCl a cid is as fo llows:
The act ion of diff ere nt ind ica tor
0

Ch lor ide J.!/!, 40 S

 '
Changes to
Indicator
Red
Moist litmus Pink
Methyl Orange Orange
Colourless
Phenolphthalein Colourless
_ . ,,
---- . h ctive meatls to liberate Hydrogen Qos''
• Action on metals: Hydrochloric acid (dilute) reacts wit a . ound' ·1he 9os
produced is 'Colourless', odourless' which burns wit. h "Popping s H t .
Mg + 2HCl ~ Mg~l2 + 2
(dil) Magne1sum
chloride
Zn + 2HCl ~ ZnCl2 + H2t
(dil) Zinc
Chloride
Fe + 2HCl ~ FeCl2 + H2 t
(dil) Ferrous
Chloride
2Al + 6HCl ~ 2AlCl3 + H2t
(dil) Aluminium
Chloride

~ Important
-.. Only the metals placed above hydrogen in activity series can displace hydroge
n form acid:
• Reaction with metallic oxides:
On reaction with metallic oxides, dil. Hydrochloric acid forms salt and water.
ZnO + 2HCl (dil) - - t ZnCl2 + H2O
MgO + 2HCl (dil) - - t MgCl2 + H2O
CuO + 2HCl (dil) - - t CuCl2 + H2O
Na 2O + 2HCl(dil) - - t 2NaCl + H2O
• Reaction with bases (hydroxides): On reaction with bases, dilute HCl undergo
es neutralisation reactions
to form salt and water.
NaOH + HCl(dil) - - t NaCl+ H2O
Mg(OHh + 2HCl(dil) - - t MgCl2 + 2H2O
Zn(OHh + 2HCl(dil) ~ ZnCl2 + 2H 2O
• Reaction with salts of weak acids:
(1) (Reaction with carbonate and bicarbonates): Dilute Hydrochloric
Acid reacts with metalLic
carbonates and Bicarbonates to liberate carbon dioxide gas. The gas produce
d is colourless, odourless
with brisk, effervescence. The gas turns lime water milky.
NaCO3 + 2HCl ~ 2NaCl + H2O + CO t
(dil)
2
CaCO3 + 2HCl ~ CaCl2 + H2O + CO t
(dil) 2
KHCO 3 + HCl ~ KCl + H2O + CO 2t
(dil)

(2) Reaction with metallic sulphites and bisulphite: Dilute Hydrochloric

acid reacts with metallic
sulphites and bisulphites to liberate sulphur dioxide gas which is a colourless
gas having the odour of
burning sulphur.
Na 2SO 3 + 2HCl ~ 2NaCl + H2O + SO t
(dil)
2

KHSO 3 + HCl - - t KCl + H2O + CO 2t

(dil)

1.~
-.vu rrrr
...'
c::S ~art ICSE Chemistry c1 ass
Edu~ · x
 d
metallic sulPhides· D'l h'd s to pro uce
('.3) Reaction with
h' h. a colourless 1Ute Hydrochlorl_c add roacts with meta llic sulp I e
H2S gas w ,c rs h. , ~
9as avln 9 h O
Na 2s + 2HCl t odour of rotto n egg.
(dll) ~ Nacl + H;,St
2

FeS + 2HCl
(dll) ~ FeCl2 + H2St

, precipitation Reaction: (Reaction .h

ion reacts with
Hydrochloric acid and give a thick ;rt ~ilver Nitrate) AgN0 3 (silve r nitrate) solut
cur Y whit e precipitate of silver chloride.
Ag NO
3+ HCl --; AgCl.J, + HN03

A 1n,portan t
white precipitate is insoluble in nitric ac,'d but soluble · ammonium hydroxide solution and form a comple salt called
,.~e
,,, m m
diammine silver chloride
AgC[ + 2NH40H ~ [Ag[NHJY2r ci- + 2H20
[Ag(NH:J2J+ Ct+ Nitric aci d~ wh'1te ppt of Ag Cl.
(aq)
i5 h
, Formation of aqua regia: Aqua re ia
concentrated nitric acid. It is used fo; 1ssolv1ng noble metals like gold and platin
ric acid and one part of
d' t _ree part of concentrated Hydrochloum.

HN03 + 3HCl ~ NOCl + 2[Cl] + 2H20

(cone) (cone) Nitrocyl Nascent
chloine chloine
Pt + 4[Cl] ~ Ptc 4
Platinum chloride
(IV)
Au + 3[Cl] ~ AuCl3
[Gold or Aurum Chloride]
(Ill)

, Reaction with Ammonia:

ide.
to form dense white fumes of ammonium chlor
Hydrogen chloride gas reacts with ammonia
NH3(g) + HCl(g) ~ NH 4Cl(s)

Uses .
• It is extensively used in manufacture of
dyes, durgs, paints and preparation of aqua regia
• It is used in Calico printing industry, tann
ing industry etc.

Test for Hydrogen Chloride gas and Hyd

rochloric acid
in ammonia solut ion is
• HQ gas gives thicker white fumes of
ammonium chloride, when a glass rod dipped
held near the vapours of acid
NH3 + HCl ~ NH4Cl
e of silve r
both the gas and acid, it gives white precipitat
• When silver nitrate solution is treated with
chloride.
AgN03 + HCl ~ AgCl.J, + HN03

~ Important
le in ammonium hydroxide.
I.it The precipitate is insoluble in nitric acid but solub
.
f ICSESuggestions
.,. Study observation -based questions. While study
.
ing any chapter. stress upon related observatwn
s like colour changes.

form t ·
I.it U O ion of precipitates, gases temp
erature, etc.
nderstond the meaning of 'relevant obser vations.
xide.
using sodium hydroxide and ammonium hydro
.,. Ensure clarity about the cation and anion test ' ' t
· h
,.. Leorn the various reagents and reactions involved m t e amons tes s.
0

frI!__ 407
Hydrogen Chloride 1:::§!J
 . ·
lo+ Practice writing balanced chem,ca l equations
·
. . ea ents such as
Ammonium hydroxide.
1o+ Focus on the colour/ solubility of precipitates formed
uSing r g
1o+ Practice answering observation-based questions.

• Prepare flow diagrams, short notes, tables for facts and concepts. d
• Learn the Laws and definitions well with the correct terms/key wor s. h ds of preparati
0
on of salts.
1o+ Acquire knowledge of solubilities of salts especially
In dee,'d',n g the met

( OBJECTIVE Type QueSt ions )

Multip le Choice Question [ 1 marks] 6. Gas liberated w hen "HCl acid reacts ,•..
YVlth
(Strictly for ICSE Semester II Exams)
galena:
(a) 502
1. .............. is used to test HCl as well as chloride (c) 02
ion in lab.
Ans. (d) H2S
(a) AgN03 (b) NaN03 Explanation:
(c) KN0 3 (d) All of above 2HCl + Pbs ~ PbCl2 + H2St
Ans. (a) AgNO3
(gas) (rotten egg smel~
Explanation: 7. The aim of fountain experiment is to Prove
AgN03 + HCl ~ AgCl + HN03 that:
AgN03 + er
~ AgCl + N03- (a) HCl is highly soluble in water
AgN03 gives white precipitate with HCl as well (b) HCl is not soluble in water
as Cl ion. Hence, it is used. (c) HCl fumes in moist air
2. HCl is a .............. gas. (d) HCl turns blue litmus red
(a) White (b) Reddish brown Ans. (a) HCl is highly soluble in water
(c) Colourless (d) Brown Explanation: Fountain experiment prove
Ans. (c) Colourless solubility of HCl gas in water.
Explanation: HCl is a colourless gas.
8. Metal which do not liberate hydrogen when
3. A salt which is soluble in hot water, but react with air:
insoluble in cold water: (a) Cu (b) Zn
(a) Pb(N03h (b) PbCl2 (c) Mg (d) Ke
(c) HClO (d) KCl Ans. (a) Cu
Ans. (b) PbCl2 Explanation: Cu is present below hydrogen in
Explanation: PbCl2 because water is a hard activity series. Hence it can't replace hydrogen
from acid.
solvent Hot water weakens the lead ion-anion
bond. 9. An acid which is monobasic:
4. Mixture of Nitric acid and HCl is known as: (a) HCl (b) HN0 3
(a) Aqua regia (c) HCOOH (d) all of above
(b) Mineral acid
Ans. (d) all of above
(c) Organic acid (d) None of these
Ans. (a) Aqua regia Explanation: All the acid release one W ion.
Hence they are monobasic.
Explanation: Aqua regia is combination of cone.
HCl and cone. HN0 3 in molar ratio of 3 : 1. 10. Aqueous solution of HCl gas is known as:
(a) Aqua fortis (b) Aqua Regia
5. A colourless solution which gives a white
(c) Oil of Vitriol (d) Muriatic acid
precipitate with HCl
Ans. (d) Muriatic acid
(a) Zn (b) NH 4 0H
Explanation: Muriatic acid is aqueous solution
(c) NaOH (d) AgN03 ofHClga s.
Ans. (d) AgNO3
11• The aim of the Fountain Experiment is to
Explanation: prove that:
AgN03 + HCl ~ AgCl + HN03 (a) HCl turns blue litmus red
(white ppt)
(b) HCL is denser than air
0
rrr.rr
408 l-t7 ,-J_
EdU L Ort ICSE Che mistry Cl
 t-fCl is highly soluble in water
(C)
(d) t-fCl fumes in moist air. [ICSE 20 161
Lh Caution
1-.
.
fi ntain ts crea
ted as a
. eme solubility
Undorsrand tho fact that ou
res ult of drop in prrw:ure due to the ext~
HCl is highly soluble in water oflha gas In water.
s (c) D . h
A~, ~,cplanation: . unng t e procedure of t he 12. The drying agent used to dry HCL gal is:
fountain ex~e.nment, as t he dropper contai ning
(a) Cone. H2SO 4
water is mJect ed, a cloured fo untain is
(b) ZnO
btained. This shows t hat HCl gas present in
(c) AL20 3
~,e flask dissolves in water du e to its high (d) Cao [ICSE 2019]
solubility. Ans. (a) Cons. H2so 4
Explanation: Ionic compounds disassociates
cor HO ,s highly soluble in water. into ions completely. Among alcohol, carbonic
[Marking Scheme] acid, sucrose and sodium hydroxide only sodium
hydroxide is ionic and rest are covalent.
WJ What Ex~miners say .
A or Concentrated H2S04
,.. ManY candidates chose the incorrect option of HCl (Marking Scheme]
turning blue litmus red. Although HCl does turn blue
UtrnUS solution red, the formation of fountain due to ~ What Examiners say
ettreme solubility in water was ignored by many I-. A few candidates got confused between the drying
candidates. agent of ammonia and HCl gas and selected CaO
instead of conc.H2S04.

( SUBJECTIVE Type Questions)

dense, white vapours as air contains oxgyen.
Fill in The Blanks [ 1 marks]
18. Lead nitrate give ............... ppt on reacting
13, HCl has the molecular mass of with HCL.
Ans. 36.5 Ans. White
Explanation: Explanation:
HCl = (1 x 1) + (35.5 x 1) Pb(N0 3h + 2HCl ~ PbCl2 + HN03
= 36.5 (white ppt)

U. HO is - ..-- ·-· times heavier than air. 19. Round bottom flask are used to heat at
AAS. 1.28 ............... temperature.
Explanation: HCl gas is a gas which is 1.28 Ans. high
times heavier than air. Explanation: As it is more resistant to fracturing
under vaccum.
15. NaQ is used in preparation of HCl as it is
- · · in nature. 20. ............... are the constant boiling mixture.
Ans. abundant Ans. Azeotrope
Explanation: NaCl is a compound which is Explanation: Azeotrope, a mixture of liquid t hat
abundantly found in nature and is used for has constant boiling point because t he vapour
making HCL has same cotnposition as the liquid mixture.

16• HQ is aiau
1 - kn
- own as ............... act"d . 21. Oil. HCl reacts with thiosulphates to produce
Ana. Muriatic ............... gas.
Explanation: Aqueous solution of HCl is known Ans. S02
as Muriat ic acid. Explanation:
17. HQ gas gives ............... fumes when It Is Na S20 3 + 2 HCl -➔ 2NaCl + S02 + H20 +S
2
A. exposed to air. (dl l)
118
• White
22. The colour of precipitate of sulphur is ............. .
~Pl.anation: When HCl gas is exposed to air,
Ans. yellow
Cl gas condenses with moisture in air to
0
.r
JfI!_
Hydrogen Chloride (::;gJ 409
 2 3 Qui.ckli. me 1s
· not use d to dry HCl gas bec
aus e
• .............. (Ca O is alk alin e,
CaO is acidic, Ca o is
27 .
neu tral ).
[ICSE 201 4] (A) Silv er chlorid e Coty"'" (I~
Ans. caO is alk alin e
(B) Fou nta in (i) Acidic
Exp lan atio n:
experim ent {Ii) Cori11:a
CaO + 2HC l ~ CaC l + H rnlxtu rn: bo1u""
2 20 (q Mo ist HCl r, ...
GoO is ,a~kalin~ (D) Azeotrope (Ill) White PPt
(E) Od our of HCl (I\/) Puri
[Ma rkin g Scheme] () 9ent:
...
An s. (A) -(11i), (B)-(v), (C)-(i), (Du " HCl 9aa
Jvl What Examiners say 1
;;, t'.E) _
\' 1, 1, -(,v)
"'- Perhap s kee ping in min d Tr ue / Fa lse
the oxidizing natu re of
HN0 3 can did ates sug ges ted 28 . HCl gas is drie d up by using .
the form atio n of S0 k[ l rnar v '.
inst ead of N0 2• 2 An s. False
quic Urne.
24 . Pot ass ium sul phi te on Exp lan atio n: Bec aus e quick lime
rea ctin g wit h .
hyd roc hlo ric aci d rele ase
s ............... gas . (CL2, CaO + 2HCL ~ CacL + Hreac o
t With Hr
2 ~
S02 , H:iS) 29 . HCl cov erts mo ist blu e Utmus pa 2
[ICSE 201 7]
Ans . S02 per red.
An s. Tru e
r--"Q -
' (-"" , . .
S02 or,Sulpbtfr ~ioxide Exp lan atio n: Moist HCl is acidic
, ,· in natu
can rele ase H+. re as it.
. [Ma rkin g Sch,em e] ·
30 . The com pou nd for me d by reac
Jv] What Examiners say tion between
Ag N0 3 and dil HCl is solu ble in
excess NH 0H.
"'- A few can dida tes mad e mis Ans . True 4
take s in sele ctin g theg as
rele ase d.
Exp lan atio n:
,& Caution AgN 03 + HCl(dil) ~ AgCL + HNO
"- Und erst and the way s in whi 3
ch acids rea ct differently 31 . Aq ua reg ia is 3: 1 mo lar ratio
with sulp hite s and sulp hide of cone. HN03
s and sup plem ent this
information with actu al practica
l work. and con e. HCl
Ans . False
25 . Dry hyd rog en chl orid e gas
can be col lec ted
by -- -- - dis pla cem ent of air. Exp lan atio n: It is 3 : 1 mo lar ratio
of cone. HO.
and cone. HN03
(do wn wa rd/ upw ard )
Ans. Upw ard 32 . Cu giv es H2 gas on rea ctio n wit
h dil HCl
Ans. False
U pwa rd
Explanation: Cu can 't rep lace
Hydroge n frorr
[Ma rkin g Sch em e] HCL.
g,;J What Examiners say Ve ry Sh or t An sw er Ty pe
- This que stion was atte mpt ed well
by mos t candidates.
Questions
[ 1 ma rk ]
Ma tc h th e Fo llo wi ng 33 . Ho w HC l helps in digestion?
[ 1 ma rk ]
Ans. HCL bre ak dow n the foo · enzL1f11""
26. Col um n (I) d and d iges t1ve_ . ~ od.
Col um n (II) spli t up pro tein . It also kills
the bact eno in fo
, (A) H2S (i) Pop up sou nd 34 . Ho w can we collect the HC l
gas?
(B) CO 2 Ans. HC l gas can b e
\ (ii) Bur nin g sul plu r co llected by upwor<l
disp lace m ent of a ir.
odo ur
(qS 02 35 . Wh o discovered the HCL gas
(ill) Red d ish bro wn first?
1
Ans . Gla ube r in 164 8.
(D) N0 2
1
I (E)
\ (Iv) RDt ten gas
36 . Wh at Is the role of activat .,,
1
H2 j M Brl1 k effe rve sen ce ed carbon
L pre par atio n of HCL?
Ans . (A)- (iv) .. (8) -(v), (C) - (t i), (D) Ans . Act i vate d car bon abs
- (til), (E) -(i) orbs hyd rogen which
increas es rea ctiv ity.
0

41 0 /;J,, Ed uC art ICS E Ch em ist ry

C las s X
 ,
j1•
Name the substance used
to dty th
concentrated Sulphuric ac·d
I
!-(IS•
e Hct gas.
I •
Explanation:
S Give reason why nitric acid .
HCl + AgN0 3 ~ AgCl + NaN03 : ,I
j ' the prepartion of HCL. is not used during :
Hydrochloric
Nitric acid is volatile and Acid
f,,.OS• along with HCL may volatilise out
Dilute hydrochloric acid ,, •
"9 WhY eao and P20s can't be
1 •
agent? used as d • [Marking Schem~t
tying
~
r<I- What Examiners say
Ans, caO and P20s are very reactive With HCL.
~ Most students answered this question correctly.
J11, What happens when HCl is expo d .
"" . se to air? 54. Identify the gas evolved and give chemical
Ans, HCl, when exposed to air, gives White furn
es. tests in each of following cases dilute
41, Give the effect
.d. .
of HCL on litmus a
P per. hydrochloric acid reacts with sodium
Ans, HCl is ac1 1c 1n nature. Hence, it turn sulphite.
litmus paper red. [ICSE 2016]
s blue
Ans. Sulphur dioxide
42. At what .temperatur e HCL forms cons 2HCl + Na2S0 3 ~ 2NaCl + H2 + S0 2
boiling mixture. tant This turns lime water milky and turns acidified
Ans. HCl forms constant boiling mixture at uoac. K2Cr207 (Potassium dichromate) paper green.
43, What is the effect of HCL on skin? 55. Dilute hydrochloric acid reacts with iron (II)
Ans. HCl is corrosi_ve in nature and as such it gives sulphide. [ICSE 2016]
blisters on skin. Ans. Hydrogen Sulphide.

44. Name the gas evolved by the action of 2HCl + FeS ~ H2S + FeCl2
concentrated sulphuric acid on NaCl. Gas has smell of rotten eggs and turns lead
acetate paper black.
Ans. Hydrochloric gas (Hydrogen chloride-HCl)
'),/ .... /,)";"<l.1-''£; ✓ ;~,,: - ..

45, Name a gas which can be used in fountain : · 'tlilfils, orange potassium
experiment. t: ,, '.~ ~;~,. ·., , ,
\, ;'.///'¥ / • ,,

Ans. Hydrogen chloride, Ammonia. .e ~ 9:rn9r~~ lead acetate

lve,,r,:y; qc :r5·•,t ': ,
',~✓-
46. Why HCl is not collected over water? .
',/,\,--'.'·~'/ ..,_~ ,;,,;-(:,

" J,,/~i'.,,;:,!l~;f;f%J,J~arki~g. Scheme]

/ ,,

Ans. HCl is highly soluble in water.

~ What Examiners say
47. Name the solvent used for noble metal. • H2S incorrectly identified or Equation written without
Ans. Aqua Regia. highlighting the gas. Or Physical test such as smell
instead of chemical test or the word paper I solution
48. What is the nature of aqueous solution of not specified when K2Cr201 / KMn04 was used for
HQ? testing.
Ans. Acidic. ~ Caution
49. What property of HCl is demonstrat ed when • Ensure not to get confused between sulphite and
it is collected by downward delivery? sulphide
Ans. It is heavier than air. 56. Name the gas produced in action of dilute
hydrochloric acid on sodium sulphide.
SO, What is the odour of HCl gas?
[ICSE 2018)
Ans. Pungent, suffocating.
51. What is the effect of HCL acid on
phenolphthalein?
Ans. It becomes colourless.
I
52• Name the gas which react with ammonia
· to
give white fumes.
'WJ What Examiners say .
• Most of the candidates answered this sub-part
Ans. Ammonia react with HCl and gives white fumes. correctly.
53, ldentitiy the acid on mixing with silver nithr~the
Write Balanced Equations [ 1 mark l
solution produces a white precipi· 'tate w 1c
'd
• • hydrox1 e.
is soluble in excess ammonium [!CSE 1s] 57 • Quick lime reacts with HCl gas.
20
Ans. CaO + 2HCl ~ CaCl2 + H20
Ans. Hydrochloric acid 0

Hydrogen Chloride l::::flll

JrI!_ 411
 . thiosulph ate reacts with dit Hct t
sodium . f 0
Ans. d e sodium chloride, gas o sulphur dio .
l "de is treated with concentrated . X1de
Pro uc d sulphur .in a ye Lt ow solid form ,
58 Sodium ch on 0
water an •
• sulphuric acid above 200 C.
Na2S2O3 + 2HCl - j 2~aCl + S + H2O + S021
c ➔ NaHSO4 + HCl
2000
+ H so 4 <
Ans. Na Cl 2
nesium strip is dropped in dil HCL
73. Mag l d'
5g. Zinc is placed in dil. HCl. esium met al slow y 1ssolves With th
Ans. Zn + 2HCl ~ ZnCl2 + H2 Ans. Magl nti'on of a colourles s and odourless e
9as
evo u .
60. Iron Sulphide (11) is treated with dil. HCl. w hich burns off with popping sound.
Ans. FeS 2 + 2HCl ~ H2S + FeCl2 Mg + 2HCl ~ MgCl2 + H2
dil
61. Sodium hydroxide is treated with dil. HCL.
Ans. Na OH + HCl ~ H2O + NaCl gas is passed through
74• Hydrogen chlorid~
solution and the product thus
lead nitrate
62. Potassium permanganate is treated with
cone. HCL formed is heated.
Ans. 2KMnO 4 + 16HCl ~ 2MnCl2 + 2KCl + 8H2O Ans. A white precipi:a te is formed which gets
+ SCl2 dissolved on heating
Pb(N0 3)2 + 2HCl ~ PbCl2 + 2HNO 3
63. Red lead is warmed with cone. HCL.
75. Copper sulphide is treated with di!.
Ans. Pb 3O4 + 16HCl ~ 3PbCl2 + 4H2O + Cl2
hydroch loric acid.
64. Magnesi um metal is treated with dil. HCl. Ans. Rotten egg smell of hydrogen sulphide (H 2o)
Ans. Mg + 2HCl ~ MgCl2 + H2 gas is given out.
65. Sodium hydrogen carbonat e is treated with CuS + 2HCl ~ H2S + CuCl2
dil. HCL. is treated with
76. Mangane se dioxide
Ans. NaHCO3 + dil. HCL ~ NaCl+ H2O + CO2 concentrated hydrochloric acid.
66. Sodium sulphite is treated with dil. HCl. Ans. Black coloured mangane se dioxide on reacting
Ans. Na 2SO3 + 2HCl ~ NaCl + H2O + SO2 with cone. hydrochl oric acid gives light brown
coloured solution with the evolution of greenish
67. Ammonia is mixed with hydrogen chloride yellow coloured gas.
gas.
Ans. NH3 + HCl~ NH4Cl MnO2 + 4HCl ~ MnCl2 + 2H2O + Cl2 i
(gas) (Cone)

68. Silver nitrate is treated with hydrochloric 77. A few drops of dil. hydrochloric acid are
acid. added to silver nitrate solution followed by
Ans. AgNO3 + HCl ~ Ag Cl+ HNO3 addition of ammonium hydroxide solution.
69. Concentrated hydrochloric acid and Ans. A white precipita te of silver chloride (AgCli) is
potassium permanganate solution. formed which dissolves in excess of NH 4OH.
[ICSE 2012] AgNO3 + HCl ~ AgCl J.. + HNO3
Ans. 2KMnO 4 + 16HCl ~ 2KCl + 2MnCl2 AgCl + 2NH 4OH ~ [Ag(NH 3)zj+ Cl- + 2H20
+ 8H2O + SCl2 the gas envolved when Potassium
78. Identify
sulphite is treated with dilute hydrochloric
State relevant observation [ 1 mark ] acid. [ICSE 2013]
70. When platinum is added to aqua regia. Ans. Sulphur dioxide {SO 2)
Ans. Platinum dissolves in the solution of aqua regia.
Chemical Equation:
71. Dilute hydrochloric acid is added to copper
K2SO3 + 2HCl~ 2KCl + H 2O + SO2i
carbonate.
79• Identify the gas envolved when Concentrated
Ans. When dil. HCl is acjded to copper carbonate a
brisk effervescence is seen due to the evolution hydrochloric acid is made to react with
of CO 2, with formation of copper chloride. manganese dioxide [ICSE 201 3]
CuCO 3 + 2HCl ~ CuCl2 + H2O + CO 2 i Ans. Chlorine (Cl 2)

72. Dilute hydrochloric acid is added to sodium Chemical Equation:

thiosulphate. Mn02 + 4HCl~ MnCl2 + 2H2O + Cl2 j

,., JrJ.!.. r- - '- . ,.....,_ ~i-

So. copp er su_lphide
t,ydroc hlone acid
is
trea ted .
. Wtth dilute
p..ri
s. Rotten egg smel ling gas
chem ical equa tion
(Iese 20131 &. Caution
(H2S) is evolved. .._. Theory needs to be supplemented with
practical
demonstra tion so that students can
CuS + 2HC l ~ CuC l recall
obse rvations easily.
2 + H2 s i
SS.• A few drop s of dilu te hydr och . 84. Dilute Hydrochloric acid is adde d to Cop
added to silver nitr ate sol t· lone acid per
are carbonate. [ICSE 2016 ]
add1.t1on
. f
o amm oniu m hydu ton foll .' owe d Ans. Colo urles s gas whic h turn s lime wate
rox1de solution. by in evolved.
r milky
. . . CuC 03 + 2HCl ~
Ans, A whit e prec 1p1t ate of Silve r Chl [ICSE 20131 CuCl2 + H2C0 3
.
solu ble in exce ss of NH oH is b o~id A colourless and odourless ·g as evolves with
4 e (AgCl)
o ta1n ed. brisk effervescence which turns Ume wate
Chemical Equ ation : r
milky.
HCl + AgN 03 ~ Ag Cl+ KN03
lf7l ,[~ar king Scheme}
t •·,
r'V Wh at Examiners say
(white ppt)
.._. Observation of blue ppt. was incorrect
82. as well as the
When dilu te hydr ochl oric acid formation of CO 2 as a product. Either the
is adde d to formation
sodium carb onat e crys tals. of bluish green solution or the evolution
of brisk
[ICSE 2014 } effervescence of gas that turns lime water
Ans. Pres ence of Nick el as milky was
a cata lyst and expected.
temp erat ure of 200° C. 0

Explanation:
Lt, Caution
_,. Understand the fact that identification
of products
C2H2 + H2 Ni and stating the observations are two differ
-----4 C 2H 4 . ent things
200° c .._. Understand tests for identification of
gases which
are colourless and associate the term such
' ' <(,' -,_·" V ;-.,, as brisk
Brisk effer vesc ence <;>f q,,ga s w~lch /:t(iin
" ,, , ,
effervescence with a gas such as CO .
lime wate r milky,., ' :§~ 2
'; , ,, ,, ,;',f;:.,* ,,.f 85. Dilute Hydrochloric acid is add ed to Sodi
' "< ' 'y ..: _.<, ·, 7· ?,~--·,;;jx "'</:} ,,, um
lf..1~r:~ing:$"c ij~m¢f; thio sulp hate .
~;••'l?,_· r~--.,c~v:!,;_~
.,,,.. ,..,.,,, __ .,..."ol' ..,'..-"4,.,,,
[ICSE 2016 }
Ans. Yellow prec ipita te of sulp hur is form
~ Wh at Examiners say
ed
Che mica l Equation:
.,. Candidates focu sed on ident ifyin g
the products Na2S203 + 2H Cl~ 2NaO +St + H 0 +
instead of stati ng the obse rvati on of a colou 2 S02 i
rless gas,
turning lime wate r milky, being evolved.
fu Caution
.,. Stude nts shou ld know the fact that when
observations
are aske d mere ly ident ifyin g the prod
uct is not
sufficient
.,. Insist on answ ering obse rvati ons base
regular tests.
d ques tions in g;J What Examiners say
.._. S0 2 gas was identified witho ut stating the
test for the
83. Dilute Hyd roch loric acid is add ed
to Lead
gas. Formation of Sulphur particles was
men tione d
nitrate solu tion and the mixture is heat without stating the colour. Some candidate
s gave
ed. wrong results for the tests of the gas evolv
ed.

Ans. Whit e prec ipita te is form ed whic h

[ICSE 2016 ]
6, Caution
disso lves '- This particular test of dil. HCI with
Nai$ O3 and
on heat ing. Na 2S 2O3 should be understood.
Chemical Equation: 86. Action of dilute Hydrochloric acid on iron
Pb(N 0 3)i + 2HCL ~ 2HN 03 + PbC (II) sulphide.
l2 -1 [\CSE 2017}
whit e ppt. Ans. On reac ting iron (II) sulphide wit
h dilut e
Hydrochloric acid, rotte n egg sme
A white prec ipita te soli,lble on heating. lling
hydr ogen sulp hide (H 2S) gas is evolved.
[Marking Sc:heme) Chemical Equation:
~
rV Wha t Examiners say
FeS + 2HC l ~ FeCl2 + H2S
,.. Inste ad of stati ng the obse rvat Gas wit h O rotte n egg smell evolved.
ion, candidate s
either wrote the equa tion or nam ed
the pr?duct. [Marking Scheme]
Some cand idate s gave an incor rect obse
rvati on of
formation of redd ish brow n gas.
0
i.,3
Hydrogen Chloride t::i !) ..., _ r_
J(I!
,
 93. NaOH + HCl ~
~ What Examiners say OH + HCl ~ NaCl + H20
Ans. Na
_,. Most candidates answered this part correctly. A
fe wcandidates committed errors such as wri:/ng 94. 2KMn04 + 16HCl ~
theequation or gave the test for S0 2, KMN0 4 + 16HCl ~ 2KCl + Mnct
Ans, 2 2
87. Identify the salt when dilute HCLIs added to + 8H20 + SC[
a salt Q, a brisk effervescence Is produced 2
95. NH40H + HCl ~
and the gas turns lime water milky.
When NH 40H solution Is added to the Ana, NH 4OH + HCl ~ NH4Cl + H20
-
above mixture (after adding dilute HCl), 96. MgS03 + 2HCl ~
it produces a w hite precipitate which is Ans. MgS03 + 2HCl ~ MgCl2 + S02 + H20
soluble in excess NH 40H solution.
[ICSE 2017]
97. NaHS + HCl ~

Ans. Salt Q is Zinc Carbonate Ans. NaHS + HCl ~ NaCl + H2S

t,' ,.,, 98. MN02 + 4HCl~
ZnC03 or Zinc Corbonate Ans. Mn0 2 + 4HCl ~ MnCl2 + 2H20 + Ct2
,• · [Marking Sche.nie];
' I ' , ' , ,, 99. Marble chips + Hydrochloric acid~
wJ What Examiners say Ans. CaC0 3 + 2HCl ~ CaCl2 + H20 + CO 2
• Some candidates identified ZnC03 correctly while
others listed either Zn(HC0:3) 2 or ZnS04 or ZnS03. 100. Calcium sulphate + Hydrochloric acid ~
Some included Pb 2+ salts as well. Ans. CaS0 3 + 2HCl ~ CaCl2 + H2 + S0 2
88. Lead nitrate solution is mixed with dilute 101. Action of Hydrochloric acid on sodiurn
hydrochloric acid and heated. [ICSE 2018] bicarbonate. [ICSE 2016]
Ans.White precipitate is formed which dissolves Ans. NaHC0 3 + HCl ~ NaCl + H20 + CO 2
on heating.
;;('· f./ .,: ,.

Chemical Equation: .. ·NaCl +~20:+ CO2

fa1t .r ·
Pb(N03h + 2HCl ~ PbCl2 + 2HN03 •· ": [Marking Scheme)
,,ii;JI ,; , / 4'"

, ,'-,-~. / ' <,, t~-. ·~: ,;~-.__: ,:...·

A white · pre~i,plt~t ~~) g'.~ff ,21-1 What Examiners say
dissolves· ·on ·. heatirtg<'d'r: :Jti
/ . ;' •~'):•n /c• J·<;·
L. • Some candidates misrepres ented the reactant as
precipit9te ,: 1$/, (orm;~i;t;:.tb4t <
Na 2C03 instead of NaHC0 3 while some others wrote
colourless'solcitlOPJS; obsefv '
/ _;:;J}t}:}tl#M~?,J: the product as H2C03 instead of H20 + CO , an often
repeated error.
2

~ What Examiners say L'.t. Caution

• Instead of white precipitate many candidates wrote 1..,. Read the question carefully and understand the fua
reddish brown fumes of N0 2. Some wrote the that carbonates/bicarbonates reacts with adds to
equation without stating the colour of the precipitate.
form H20 and CO2 (Brisk effervescence) along with
A few candidates expressed the answer by leaving
the salt and H2co3
out the effect of heating on the solubility of PbCl .
2

Complete and Balance 102. Action of dilute hydrochloric acid on

the
magnesium sulphite. [!CSE 2018)
Chemical Equations [ 1 mark ]
Ans. MgS0 3 + 2HCl ~ MgCl + H 0 + S0
89. Fe + 2HCl ---+ 2 2 2
"\'".,i~ f\\"~
Ans. Fe + 2HCl --i FeCl2 + H2 MgSOl + i AJ:l ~ M9Cl2 +S0 2 + H·P
(dil.) [~fo~king Sd,eme]
90.
~ What Examiners say
NaHC0 3 + HCL ---+
(dil)
Ans. NaHCOj + HCL - ? NaCL2 + H20 + CO • Many candidates got confused between magnesium
2 sulphite, sulphide and sulphate. Some others erred
91. FeS + 2HCL -~ by writing one of the products as H:zS0 instead of
3
(dil) H20 + S02-
Ans. FeS + 2HCl --+ FeCl;, + H;,S
103. Action of dilute hydrochloric acid on sodium
92. Ca(HC0 3)i + 2HCl ---+ sulphide. [ICSE 2014)
Ans. Ca(HC0 3)2 + 2HCl ~ CaCl2 + 2H20 + 2C0
2 Ans. Na2S + 2HCl ~ 2 NaCl + H S i
2
0

414 Ci!, Edu(:'ort ICSE Chemis try Class X

 [ 1 m a rk 1
Na 2s + 2HCl ~ 2NaCl + H2s d ctor
Ciive Re a son . 0 poor con u
[Marking Schem e] LL t condu ctor?
116. Why anhyd rous HCL 18
while aqueo us HCL Is an exce en t the
,.t exam iners say o
d ctO r due HCL
~w .. h
'/,r ndidate s used NaOH as the distinguishing rea
Ans. An hydrous HCl is poor con u
s
is
of
g:nt
o f the ppt With ea ch so lut,on absence of ions in it whe reas a queou
"" cad rated the colour
n s ·ry h . . h excelle nt condu ctor because of presen ce
a failed to spec, t e solubilities of the ppt in t e
but ions.
reagent. full
<200°C 117• Explai n why- when the stopp er of a bottle
·in the
f(Cl + H2S04 of HCL gas is opene d there are fumes
JD'- (Cone)
air?
< 200°C
KHS0 4 + HCl Ans. HCl gas has an affinity for water. Hence, when
KCl + H2S04
~ris, (Cone) the stoppe r is opene d it immed iately reacts
> 200°C with water vapour presen t in the atmos phere
which leads to the formation of fume.
>2oo·c 118. Explain why-t hick white fumes are forme d
when a glass rod dipped in NH 4 0H is broug ht
near the mouth of bottle full of HCl gas.
Ans. When a glass rod dipped in NH 4 0H is broug ht
06- zns + HCL---+
1
zns + 2HCl- --+ ZnCl2 + H2S near the mouth of bottle full of HCl gas it result
f,J!S. in formation of Ammonium chlorid e. Hence,
i07, HCL + HN03 ---+ dense white fumes appea rs.
3HCl + HN03 ~ NOCL + 2H20 + 2[Cl]
AftS,
,,,. (Cone)
(Cone) 119. Explain why-d ry HCl gas does not affect a
dry strip of blue litmus paper but it turns red
108. Ca0Cl2 + HCL ~ in presence of drop of water .
A
Alls. CaOCl2 + 2HCL ~ CaCl2 + H20 + Cl 2 i Ans. Dry HCl is not acidic while moist HCl is acidic
(dil) in nature. In presen ce of drop of water, HCl
gas becom es moist as it dissolves in water and
109, Cu + HCL---+ forms HCl acid which turns blue litmus paper
(dil)
red.
Ans. Cu + 2Hd ~ CuCl2 + H2 i
(dil) 120. Why HCl gas is not collected over water ?
Ans. HCl gas is not collec ted over water as it is
.
110, CuO + HCL ~
(dil) highly solubl e in water.
Ans. CuO + 2HCL ~ CuCL2 + H20 121. Explain why dil. HCL can't be conce ntrate d by
(dil)
boiling beyon d 22.2% .

Ut. Mg(HC03h + HCl ~ Ans. When the conce ntratio n of HCl gas in water
Arts. Mg(HC03h + 2HCL ~ MgCL2 + H20 + CO2 becom es 22.2% by weigh t, it forms Azeot ropes
that i.e. consta nt boiling mixture. At t his
1U, Cuo + [OJ + HCl ~ conce ntratio n if the solutio n is still heate d t he n
(Cone) water and HCL vapori ses in same propo rtion by
¼. Cuo + [OJ + 2HCL ~ CuCl2 + 2H20 + Cl2 weigh t.
(Cone)
122. Hydrogen chloride gas canno t be dried over
113 [ICSE 2012]
• ~Cr201 + HCl ~ quick lime.

Alis. K2Cr207 + 14HCl ~ 2KCl + 2CrCL3 Ans. Hydro gen Chloride gas is acidic where as Quick.
+ 7H 2 O + 3Cl2 i lime (CaO) is basic, so they react with each
othe r formin g salt a nd water and hence Cao
cannot be used as a drying agent for Hydro gen
Chloride.
Expla nation:
CaO + 2HCl ---) CaCl2 + H20.

JJI! 4,5
Hydrogen Chloride c9 ,,
 AgN03 + HCl ~ AgCl + HNo
Ans. (white PPt) 3
.. f dilute hydrochloric acl'd is
123. Conductt•~:~ t~at of acetic acid. [ICSE 2018) AgCl + HN0 3 ~ No reaction
greater 'd
AgCl + 2NH40H ~ [A~(NH2h] Cl(oq),. H
.
Cl has a better conductivity than acetic aci
Ans. H t' acid A = AgN03 (Silver Nitrate) 20
as it ion izes almost completely and ace IC
being a weak acid ionizes into molecules a nd B = HCl (Hydrochloric Acid)
ions both. c = AgCl (Silver Chloride)
Dilute hydrochloric acid undergoes NO PbO 2 and Red lead react With c
complete ionlzation/ dissociation whereas 26
1 • ~Cl :cid and libera~e Cl2, What is ~:
acetic acid ,u.ndergoes incomplete or n property being shown by th
partial ionizatio~ or. dilute HCL has hig~er , ~mm O ~
metal oxides?
concent~atipn of ipn~ than acetic acid_,/,
Ans Th ese m
etallic oxides results in oxidation of He
Dilute hydrobhloric,9cid' is a stronger a~~a:', .d. . I
• Hence, they behave as ox, 121ng agents. ·
than acetic aci~/ Di_lu;e hMor6chl9ri~ ~9,1:~::-
is a strong electrolyte and ~rce~ic·,ac19.-~~.· 3 • Study the flow chart_ _and give balanced
a weak electr~Jyt~/) il~te·_· h·y~toc#pri~." equations with cond1t1ons for following
-only ions,'' ··ac~tic-_-:·:add~.. -~ions ..·_ ab~:, conversions A, B, C, D and E.
molecules/ Dil~·~e. hy~to?.~'.lorl~ ·~"Sid :· h_
higher degree··of ,dissdci9t_i~:6 th~n_1~c~d9~
acid.
~}: NaCl
A
E

MnC12
Hi:~0 B
2

~ What Examiners say

AgCI
• Most candidates wrote about the conductivity of 2000
dilute HCl or acetic acid but could not compare the
Ans. NaCl+ H2SO4 < c NaHSO 4 + HCl
(A)
conductivity of both the acids.

124. Hydrogen chloride gas fumes in moist air.

2HCl +Zn
(B)
---? ZnCl2 + H2 I

[ICSE 2019] HCl + AgNO3 ---? AgCl + HNO3

Ans. Hydrogen chloride gas fumes in moist air as (C)

hydrogen chloride gas is highly soluble in water 4HCl + MnO 2 ---? MnCl2 + 2H20 + 02
and due to its high solubility it absorbs moisture (D)
and forms mist
HCl + NaOH ~ NaCl+ H2O
(E)
As it is highty .s&l~bl~ ·'.frl w6t'
solubility/ absorbs ,moisture./91'.1. 127. Draw a diagram to show the arrangement
mist/ affinity for water. • . .?>;.? t'r, , used for absorption of HCl gas in water,
If no gas is evolved it is CuO. ' •. ·' / ? _l:}j
Why is such arrangement necessary? Give
[Marking Scheme]. reasons.

~ HClgas
What Examiners say
.,. Most candidates gave a relevant reason. Some wrote,
Fu,el ~
"because it comes in contact with ammonia gas''. A
few even wrote that it is due to the reaction between
HCl and NH3. Several candidates got confused and :::::~::::::
wrote "dense white fume s are formed''.

Short Answer-I Type Questions

[ 2 mark]
Ans. This arrangement is necessary because it
125. Solution A reacts with an acid B which prevents back suction of water into flask and
gives greenish yellow gas on reacting with prov,'d es greater surface area for the absorption
oxidising agents like Pb304 to give white of gas.
precipitate C which is insoluble in HN0 3 but
128. The diagram below shows a simple
soluble in NH 40H. Name A, B and C.
arrangement of fountain experiment.
0

416 Ci:, Edu~art ICSE Chemistry Class X

 131. I He.I (J M I Noll <f
A
cone.
141S0◄
r~ ]
1
H1!l0,1 [JCSE 20171

An&. (A) NaH:i 0,1 ► ~ ICI ...., ,,nt of Air

. I
(fl) Upward cJ1 qp au~,,,..,

NaHS0,1 + H(,l ,
Upward displocemenr of air _ :1,
1
(M<1rk.it19 ~

~ What Examiners say . ,.,

blank space A woJ
igrtore d
.._. In this part of the questio n. d"dot s A f€!w
correctly answered by most con , ~ - ' orrd vrrot:e
d of
the condition 'laboratory prepa ra:'°::a instea
4
the products formed as Na;zS0
(A) Name two gases you have studied which •'- d of
can be used in this experiment . NaHSO 4 + HCL
blank space B pertam
· ·
mg
to mev,o
.
loot For the candidates wrote
(B) What is the common property collection of HCI gos, manY was
.
mcorr ect
· which
demonstrated by this experiment? downward displacement Of air.

}.TIS, (A) Ammonia and Hydrogen chloride gas. ,& Cautionon the conditions of temperature < ~OO "C
(B) Both gases are highly or extremely soluble .._. Stress
out
during laboratory preparation of HCl and po,nt
in water.
clearly the products forme d i.e. NoHS 04 °nd H<?-_
0nd solubi lity of
you would carry out for testing .._. Correlate the knowledge of densit y
129. Give tests gases in deciding the metho d of collection of the
gas.
HCl gas and acid.
to dilute
Ans- (1) HO gas gives thick white fumes of NH 4Cl, 132. A small piece of zinc is added
hydrochloric acid. [lCSE 2019]
when a glass rod dipped in ammonia
solution is held near the vapours of acid. Ans. Brisk effervescence is seen. The gas released
NH3 + HCl ~ NH4Cl extinguishes a burning sprint er and itself bums
with a pop sound .
(2) Wrth AgN0 3 solution, both HCl gas and
acid gives white ppt of AgCL Chemical Equation:
Zn+ 2HC l~ ZnCl2 + H2
AgN0 3 + HCl ~ AgCl + HN03
Brisk effervescence / A gos giver,
130, How will you distinguish between dilute
out extinguishes burnm g splint er and
hydr;ochloric acid and dilute sulphuric acid
using lead nitrate solution? [ICSE 2017] itself burns with pop sound
fins. On adding lead nitrate solution to dilute (Mm tin g~
hydrochloric acid a white precipitate is
formed vvhich is so luble in hot water. wJ What Examiners say large
• Instead of stating che test for the gos evolved. a
On adding lead nitrat e solution to dilute
number of candidates ident ified it as H_,
S\1'4>hu ric acid a white precipitate is formed _,. Some candidates stated that the gas bums
with a
vmich is solub le in hot water. blue flame instead of stating that a burnin g splin t 's
put off with (l pop sound
On adding Lead nitrate solution ro both
they form white precipitate but the one in Short Answer.. 11 Type Questions
Ntuch the white precipitate disappears on
[ ] m,H k]
hearmg 15 HQ, while in H2S0 4, the white
prec1p1tDte remain s insolu ble on heatin g 133. (A) Name the
acid used for the
[MarkJng Scn•m•J prtpa ration of hydro gen chlor ide
;,J What Examiners soy goi In the labor atory, Why is this
-. M partic ular acid pret.rntd to other
b an!I candidatei, failed Lo correctly dii. 11ngw1- h
~tween dilute HCI and dilute H2SO4 ai. 1he1,olubl/1ty acid& ?
White precipitate formt:d w,rh HCI un heattny
0
(B) Write the ba lance d chem ical equa tion for
~~s not included and instead. ro,mar,on of b1ow11
1 gos with H~O,, was menuoned wlllch wu6 nor the labor atory prepa ration of hydro gen
Possible. chloride gas. [ICSE 2018 ]

Hyd roge n Chlo ride i:/J, 417

 (A) Write the equation for its Pre
Ans. (A) concentrated sulphuric acid is used ~or mentioning the condition requi~~ratlori
preparing HCl gas as it is an non-volatite (B) Name the drying agent used and j.
acid. your choice. "ltlf\i
(B) NaCl + H2SO4 <
2
oo•c NaHSO 4 + HCl (C) state a safety precau tion You
take during the preparatio Would
Concentrate sulphuric acid. hydrochloric acid. [ICSe;0 Of
It is non-volatile / has high boiling point <200°C 1s1
/ displaces the volatile hydroge n chloride Ans. (A) NaCl + H2S04 - - NaHSO 4 + HQ
rrom the salt sodium chloride. The temperature should be less th
. an 20o·•
(NaCl+ H2SO 4 <200°> NaHSO 4 + HCl (B) Concentrated Sulphuric acid is used (
drying agent as the other drying a O6 0
,[Marldng Sc~erne] like CaO and P20s react with HCl vap9ents
ours
.?J What Examiners say (C) Funnel arrangement should be used ·
• Many candidates did not specify whether sulphuric HCl has great affinity for water and ~s
acid used for the preparation of hydrogen chloride highly soluble in water. is
gas in the laborato ry should be concentrated or
dilute. In response to the preference of this acid over
other acids, some wrote that it does not react with
HCl gas.
• Some candidates did not mention the necessary
condition of temperature i.e., below 200 oC to ensure
Na;iS04 is not formed which has a tendency to
get fused with the glass and ended up writing the
equation which was not required as per the question
asked:
2NaCl + H;iS04 ~ Na 2S0 4 +2HCl
& Caution
• Understand thoroughly the study of compounds ~ What Examiners say
with laboratory preparation of hydrogen chloride
gas, ammonia, etc., and their physical and chemical -+ Most candidates knew the correct equation however
properties. Besides this, also discuss all possible some candidates wrote the reaction at a higher
reasoning questions related to their physical and temperature which ought to have been avoided.
chemical properties at length. -+ The occasional incorrect answer was Cao. Most
• Read the question carefully and answer to the point as however answered correctly. However. some
per the requirement of the question. candidates failed to refer to the concentration of the
.,. Clarify the technical terms used in the question. acid with the reason not clearly mentioned by many.
.,. Write dilute or concentrated whenever reference is -+ Irrelevant answers written by many as they were not
made to any acid. sure of the safety precaution.
.,. Write chemical equations with necessary conditons & Caution
134. Study the fl.ow chart given and give balanced -+ Emphasis must be laid on the dependence ofproducts
equations to represent the reactions A, B and on the condition employed.
-+ Frequent testing offactual data required
C: lo+ .
Students must be trained to analyse the data and

Mg3N2 I~ [;] +I NH4C I 136.

reason out

Study the figure given below and answer the

questions that follow:
[ICSE 2019]
Ans. (A) H20
(B) HCl
(C) NaOH
Chemical Equation:
(A) Mg3N2 + 6H20 ---, 3Mg (OHh + 2NH
3
(B) NH3 + HCl ---, NH4Cl
(C) NH4Cl + NaOH ---, NaCl + NH3 + H 0
2
135. The following questio ns are pertaining to
(A) Identify the gas Y.
the laboratory preparation of hydrogen
(B) What property of gas y does this
chloride gas:
experiment demonstrate?

418 Cl:!:, Educ:;'a rt ICSE Chem istry Class X

 less tha n
should be
The temperatu re
ich has the sam e so 4)
(C) Name another ga s wh 200° C.
'd (H
d
is
demonstrated aoiling po
~huri. ch bo 2
property and can be ntrate
d
su int an
[ICSE 20141 (B) Co nce l tile HCl
through this experiment. non -volatile and has hig
re vo a tra ted
(A) HCl gas hence can displace the mo Lace
soluble in water. as co~ ce~
A ' (S) That gas 'Y' is highly
115 gas from the salt where nd l d,sp
d a wrl
nitric acid is a volatile aci
(C) Ammonia (NH 3) .
out itself alongwith HCl gas
displacement
·,:. ~C:l or Hydrogen Chloride (C) HCl gas is collected by upw ard
l in water
• .Ver9'high solubility of HC of air.
Ammonia used for drying ~he
(D) The drying ag en t not
[Marking Scheme] horus Pentaoxrde
·' gas is quick lime or Phosp
(P20s)
wJ What Examiners say
ed this part correctly, R from the following
_. Most candidates answer 139. Identify the sal ts P, Q,
ed the gas erroneously as
barring a few who nam observations:
hydrogen chloride gas. ish green colour.
hydrochloric acid instead of (A) Salt p ha s light blu
not mentioning the high duces a black
_. candidates lost marks for On heating, it pro
of the gas in water. Some
I extreme solubility gas which did not match coloured residue. Sa lt
P produces brisk
mentioned the nature of the HCl an d the
with the question that foll owe d. effervescence with diL
ed this part correctly. e wa ter milky,
_. Almost all candidate s ans wer ga s evolved turns lim
dified po tas siu m
& Caution but no action with aci
the tests for colourless dichromate solution.
_. Emphasize on mentioning teristic odours ofgases.
gases or specifying the cha rac
(8) Salt Q is wh ite
in colour. On str on g
ervatio ns or colour changes.
_. Ens ure to see suc h obs ff ye llo w residue
com pou nds correctly. heating, it produces bu
_. Learn to identif y and nam e h brown ga s.
and liberates reddis
gram below and ces chalky wh ite
137. Refer to the flow chart dia if Solution of sal t Q produ
with conditions, wi th exc ess of
give balanced equations to D. insoluble precipitate
ver sio ns A
any, for the following con ammonium hydroxide.
. On rea cti ng wi th
(C) Salt R is black in colour
erates a pu ng en t
concentrated HCl, it lib
ich turns mo ist
Sodium Hydrogen Ammonium greenish yel low ga s wh
Chlorid e black.
Chloride a Chloride .· starch iodide paper blue
. ead Chlorid [ICSE 20 20 ]
[ICSE 2012] carbonate (CuC0 3)
Ans. (A) Salt P is copper
Ans. (A) NaCl+ H2S0 4 ~
NaHS0 4 + HC l
(1) CuC03(s) ~ CuO(s)
+ C02(g)
H2
(B) Fe + 2H Cl --- t FeCl2 + (Black)
(C) HCl + NH 3--- t NH CL + CO 2 + H20
4
Cl2 (2) CuC03 + HC l-- -t CuCl2
l - 2H20 + No reaction
{D) Pb02 + 4HCl --- t PbC 2 (3) CuC03 + K2 Cr 20 7~
pre par ed in the
U8, Hydrogen chloride ga s is sulphuric acid (8) Salt Q is lead nitrat
e [Pb (N0 3) 2J
y using con cen tra ted
laborator
(1) 2Pb(N03h(s) ~ 2P
swer the questions bO (s) + 4N 0 2(g)
and sodium chloride. An Yel low Reddish
ction: Colourless
that foll.ow based on this rea brown + 0 2(9)
mical equation for
(A) Give the balanced che N0
(2) Pb(N03)2 + 2NH40H ~
condition(s) if
H
2N 4 3
the reaction with suitable + Pb(OHh J.
any. Chalky white
con cen tra ted sul ph uric acid used plr eci pit ate
(B) ~h y ia
of con cen tra ted nit ric acid?
instea d
dioxide (Mn0 0
(C) How is the ga s collected
? (C) Salt R is ma ng ane se
(D) Name the drying ag
en t not used for Mn02(s) + 4HCl(aq) ~ MnCl2(aq) + 2H 2o (0
[IC SE 202 0] + Cl 2(g)
drying the gas. yellow)
20 o·c NaHS0 4 (gre enish
Ans ,A)
· ,, NaCl + (co ne.) H so
2 4
<
+ HCli
0

Hydrog en Chloride l:l1, 419

 recipitate of lead sulphate is fi
CuC0 3 or copper carbonat e or ~hich does not dissolve further. orrnect
copper(II) carbonate
Pb(N0 3)i or lead nitrate or lead(II) nitrate Explanation:
Mn0 2 or manganese dioxide or Pb(N0 3)2 + 2HCl ~ PbCl2t + 2HNo 3
(white ppt .)
manganese (IV) oxide
(Insoluble in cold water but dissolves in Warm
[Marking Scheme]
water)
& What Examiners say Pb(N03)2 + H2S0 4 ~ PbS04 + 2HN03
(white ppt,)
Candidates who had knowledge of practical
chemistry fo und this question easy. Some common (Insoluble both in cold and warm water)
m istakes m ade by candidates were as follows:
.,. Few candidates m ade errors in identifying the salt.
On adding lead nitrate s?lut ion, if White
Some identified it as calcium carbonate instead of
copper carbonate. precipitate is formed which dissolves .
0
.,. Som e candidates were confused and identified the heating, then it is dilute HCl. n
salt as zinc nitrate. If white precipitate formed does not
.,. Several candidates mistook the black compound to dissolve oh h~~~ing, it [s dilute H2so .
be Copper oxide. 4

& Caution / ,-. , [~arking Scheme]

.,. Demonstrate the reaction of cone. HCl on both the
black compound s namely CuO and Mn02 to see the
wJ What Examiners say
colour and understand the difference between the .,. White precipitate was mentioned by several
compound s. candidates but the effect of heat on both was not
.,. Be trained to identify salt from the observations given. mentioned.

140. Distinguish between following pairs of 141. For the preparat ion of hydrochloric acid in
compoun ds using the reagent given in the the laboratory:
bracket (A) Why is direct absorpti on of hydrogen
(A) Mangan ese dioxide and copper (II) oxide. chloride gas in water not feasible?
(using concentr ated HCl) {B) What arrangem ent is done to dissolve
(B) Dilute hydrochloric acid and dilute hydrogen chloride gas in water?
sulphuric acid. (using lead nitrate [ICSE 2018]
solution) [ICSE 2019] Ans. (A) Direct absorption of hydrogen chloride gas
Ans. (A) Mangenese dioxide, on reacting with in water is not feasible because this may
concentrated HCL gives greenish yellow lead to an explosion (as HCl is highly soluble
chlorine gas whereas Copper (II) Oxide
in water) due to heat produced when
does not react with concentrated HCL
water comes in contact with concentrated
Explanation: sulphuric acid.
Mn0 2 + 4HCl~ MnCl2 + 2H20 + Cl2i (B) Inverted Funnel anangme nt is done to
(black) (colourless) (greenish dissolve HCl gas in water.
yellow gas)
; , //' I \,
Back suction occurs (or the descriptior
On ·adding concentrated hydrochlo"ric'acid
of back suction) / HCL gas dissolves in
if a greenish yellow gas is evolved it is
water at a faster rate than it is produced
Mangane se dioxide.
Inverted funnel arrangement/ the rim
If no ga s is evolved it is CuO.
of the funnel just touches the surface
[Marking Scheme] of watertaken in th e tro ugh or correct
diagram.
"wJ What Examiners say [Marking Scheme]
• Some of the candidate s gave the equation instead
of writing the observation to distinguish between the
given pairs of compounds. With the reagent given, the ~ What Examiners say
result of adding it to one substance was specified by ~ Many candidate s gave inadequate explanation
several candidate s but not for the other substance. wit hout m entioning the effect back suction.
{B) Lead Nitrate solution reacts with dilute ~ Mo st candidates answered correctly. However. 0 fe~
candidates wrote thistle fun nel instead of inverte
hydrochloric acid to give wh ite precipitate fu nnel arrangement.
of lead chloride which dissolves on heating
whereas on reacting dilute sulphuric acid & Caution
with lead nitrate solution an isoluble .,. Presentation on back suction will give clant• y to
students.

0
b..?n l'Il C' ,..J, , r-",._rl- 1r.
 .
rr,onia 1s a compound formed b AMMONIA
Arfl Y th e comb·1
.11,ly in gaseous state but it c . nation of Lw
O
1110 an exist in m olerrion ts I.e. 'Nl trogon and Ox11gen'. Ammonia exist
ore forms b t r " . . :::i
y c,J ating it wit h different processes.

ITOP1c 1 I
STRUCTURE
AND OCCURENCE
Structure
An,monia is a covalent compound fi
ormed by the b .
1110 lecular formula of ammonia is NH A . . o nd formation between nitrogen and hydrogen The
3. mmon1a is a lewi b . .
Structure of NH3 s ase as it have a lone pair of electron.

NH3: N(7) = 2, 5
H(l) = 1

H
~ H: E: > Lone pair
H

• -Electron of N
x - Electron of H
H
I
H-N-H (Lewis or Dot diagram)

:~"!1!.__le 1. Calculate the molecular mass of Ammonia.

Ans. NH3: (1 x 14) + (7 x 3) = 17

&ame~ ;. Why Ammonia is basic in nature?

Arri. Am monia has a ionic pair in its bond structure. Due to the presence of the ionic pair, Ammonia is basic in
nature.

Occurence
n nature Ammonia exist in free form as well as in combined state. In free state, ammonia is present in small
err ounts in air and in natural water while in combined state, it occurs in the form of several compounds such as

/..rr,monium chloride, Am monium sulphate etc.

~ Important
,. /4.rnmon,a and Ammonium compounds do not occur as minerals as they are highly soluble in water.
,. Ammonia has purgent smell.
,. It 16 produced due to bacterial decomposition of urea, present in the urine.
CO(NH,), + 2H 2o ~ 2NH 3 + H2 O + CO 2

Forms of Ammonia
l\rnrnonia exist in fo llowing fo rm s.
' Gaseous Ammonia (Dry Am monia Gas) · · fi d
• Liquid Ammonia: When dry ammonia is liquified at high pressure, liquid ammonia is orme .
0

Ammonia JfI!_ 421

t::m
 • Laboratory Bench
Reagent: It is dilute so . flI'quor am mon 1·a
• Liquor Ammonia
Fortis: It
lution °
rnonia in wate r.
is satura te d solution of
\ Example 3. What Is
Arn
I wate r called?
saturated solution of
Ans. Uquo, Arnmonla amM onla n
Fo, tis.

\ TOPIC 2 I
PREPARATION OF A
MMONIA
General Method by
Salts of Ammonia
Whe n am mo nia salts
are heated with alkali. su . l k d lime et c Ammo
ch as cau st1c soda ' s a e ' n·10 .
gas 1s f0 .
rrr ~~
2NH4Cl(s) + Ca(OHh
~ CaCl2 + 2NH3 + 2H20
slaked lime
(NH4hS04 + 2NaOH
~ Na2S04 + 2NH3 +
Caustic soda 2H20
Laboratory Preparat
• ion
Reactants: Ammoniu .
m chlon.de and Calci.
• Reaction: um hy drox1'de. ,r,ca lc·1um h1 •drox1.de 1s
• l
a wa ys ta ken in
•
~ exces )
s.
2NH Cl + Ca(OHh ~
4 CaCl2 + 2H20 + 2NH3
Ex ampl e 4. Why Ca
lcium hydroxide is us
Ans. Calcium Hydroxid ed as alkali?
e is used as an alkali
other alkalis. in preparation of Am
monia as it is ch ea p
an d not deliquesce nt
• Procedure: The ~<:
reactants are finely
is fitted in slanting po gr ou nd and then taken in a ro
sition bending in the und bottom flask. Th
• Drying of gas: Am downward direction: e round bottom flas(
monia is dried by pa
co ne. H2S0 4, P20s an ssing over quick lime
d anhy, CaCl are no i.e. calcium oxide. Ot
2 t used as ammonia be her drying agents suc
ing basic, re ac ts with h as
2NH3 + H2S04 ~ them.
(NH4hS04
6NH3 + P20s + 3H20
~ 2(NH4)3P04
CaCl2 + 4NH3 ~
Example S. Why Am CaCl2.4NH 3
monium Nitrate is no
Ans. Amm onium ni t used in preparation
trate is not used in pr of Ammonia?
eparation of Ammonia
NH4N03 ~ /:; because it is explosiv
N20 + 2H20 e in nature.
/:;
NH4N02 ~ N2 +
2H20
• Collection: Ammo
nia is collected by
solu ble in wa te r. downward displacem
ent of air as it is lig
hter th an air and hig
r.~
Ammonia Ammonium chloride
and
Calcium hydroxide Calcium hydroxide
and am mo niu m
chloride
n
\...J._
. kel'
OUIC lme to
dry ammonia

Laboratory preparat
ion of dry ammonia
Aqueous solution of
4 2 2 cJ°rilJ..J! Edu Car .
Ammonia
t IC SE C he m is tr y Class x
 coUecte
6, Why Am mo nia Qas is d lby down ward displa
cement of air?
t d b d ard d'
fl /.~pl! - . co ec e y ow
ll
onia is
nw It Is
isp acernent of air as
1/ , , ,ArYl~ghte r than air
#' : ~ighlY soluble in water.
. .
ber's process
&,.cture of Ammonia by Ha . d Hydrogen 15
nu1~ ed b H , ratio by volume of Nit rog
en an
~a . ll ammonia is manu factur Y aber s Process. The
d n is
11,dustna y, ile Hy roge
I
ified air wh
' · nal distilla tion of liqu
1' 3. ogen used ·in Haber s process is obtained by fractio
i,e Nitr
, 1 .ined by Bosch proces
s.
obta

fr... caution
with decrease in volume.
I)> action is reversible
, exothermic and proceeds
~ ~~
urable Cond itions
o o
faVO
rature - 450 - 50 0 C
' Tem e _ Above 20
puer 0 atm
press . .
' Cata lyst _ Finelly d1v 1ded Iron
Al20 3
oter - Molybde m or
nu
,' prom s.
ed for Haber's Proces
n wh y low temperature is requir
~ Giv e reaso
ause reaction is exothe
rmic.
pe rat ure is required for Haber's process bec
:. . Low tem

Recovery and Hydrogen by:

a is sep arated fro m the unreacted Nitrogen
Ammoni
(l) Liquification
(l) Absorbing by wa ter Hydrogen (By Bosch
air) 1 vol process) 3 vol
Nitrogen (from liquid
t t

Compressor

Catalytic chamber
)
~"'-"".,,._ ,,--Catalyst (S00°C
Compressor
250 atmospheres
pressure
Cooling
chamber
liquid out
=== .- Cooling
Uncombined - -r-- """-=
Liquid-in
gases
! Liquid ammonia
ess
FlowChart ofn Haber's Proc
Dry nitroge
lvol Electri cally Condenser wit h
heated catalytic cooling pipes
chamber Liquid am monia
Dry hydrogen yled back
3vol Uncombined N2 and H2 rec

Ammonia ~ 423
 1o ~MO ...
N, + 3H, ' 4')0" 1
2NH3 + Heat
1no·'r.
abo ve 200 otm
A-1" Im porta nt
rt.T'
_,. This rcoctio n is cxothomii
c, hence low tamperature , reo
will fctvour the synthes/s. At low temperature this
slowly. .
• Since 4 volume of rea ctio11 occu
cta nts produces 2 volume , r~
of Product, so high pressure ;8 favourabl e.

\ TOPIC3 I
PROPERTIES OF AMMON
IA
Physical Properties
(1) Colour: Colourless
(2) Odour: Strong, Pu nge nt,
Choking sm ell
(3) Ta ste: Slightly Bitter
(4) Lighter tha n air
(5) Highly soluble in wa
ter
Fountain Experiment
Th is exp eri me nt is do ne
to prove tha t Ammonia
is higly soluble in wa ter .
Apparatus
• A round bo tto m fla sk fill
ed with am mo nia gas.
• Mouth of the fla sk is fill
ed with a rubber sto pp
dro ppe r containing wa ter er with tw o holes, on e
for a jet tub e and the
. other for c
• A tro ug h containing red
litmus solution.
Procedure
(1) Th e dro ppe r containing
wa ter is squeezed.
(2) As few dro ps of wa ter ent
er the flask am mo nia gas
hig h solubility. This cre ate pre sen t in the fla sk ge ts
s a par tia l vacuum in the dissolved in wa ter, due to;..
flask. ~
(3) Sin ce, out sid e pre sur e is
higher, the red litmus sol
blu e fou nta in. ution rus hes up thr ou gh
the jet tub e and emerg
es as "

Ammonia ga s- -- -'-

Jet tub e Blue

-++---4--
--i
fountain

Dropper - - - - -n1

Red litmus
bolu tion

Fountain experiment
Chemical Propertie s
(1) Dr y Am m onia ii, a cov
alent mo leL ule So, it b
neutra l even in liquifie
d fo rm.
NI h I H-10 ' _. NH 40H

!::la
0

424 Educ 'ar t ICSE Chem

istry Class X
(t)
,Action of Indicators:
.
, I
Indicator
Original
Mois t lit mus To
Methyl Ora nge Red Blue
Phenolph t hal . Orange Yellow
surning of Ammonia: Ammon·- .~ -e,n C0 l
- - ourless
(3) of ammonia
· · · · 10
,s ignited in atmo s h ts ne1th er combustibl
Pink
. . -
P ere of oxygen it b e n~r tt ts a supp
orte r of combustion. However ifjet
4NH + ' urns with green flame.
3 502 ~ 2N 6H
. - - - - - -· 2+ 20

Dry --.- -__ ,,

ammonia gas -========+--Oxygen
catalytic Oxidation of Ammonia
In the presence of platinum at 800° C
•Ammonia
. react
s with • nitric
. . oxide
oxygen to give . and water
4NH 3 + so vapour
2 Pt.soo c
0

6H2O + 4NOt + Heat

2NO + 02 ~ 2NO 2
Dry 0 2 (Brown gas)

Dry NH 2

Example 8. Why ammonia and oxygen is dangerou

s?
~ Ammonia and oxygen is dang erou s beca
sue it is explosive in nature.
Ammonia as a reducing Agent
• Reduction of metallic oxides: Ammonia
reduces heated metallic oxides to correspon
vapou rs and nitrogen ding metals, wate r
3CuO + 2NH 3 ~ 3Cu + N2 + 3H2O
Heated Pinkish
(Black) Red
3PbO + 2NH3 ~ 3Pb + N2 + 3H2O
Heated
(Yellow)
• Reduction of Chlorine to Hydrogen
chloride: When chlorine reacts with amm
Which further combine s with excess of amm onia , it is reduced to HCl,
onia to form ammonium chloride.
(l) When Ammonia is in excess:

(exce ss)
The yellowish-green colour of chlorine disap .
pears and whit e fum es of Ammonium chlor . d
ide are forme ·
(2) When Chlorine is in excess:
NH 3 + 3Cl2 ~ 3HCl + NCl3
The yellow coloured highly explosive liquid
Nitrogen t richloride is form ed.
0

Am monia lJ} , 425

 Reaction with acids . ammonium salt
. b . 0
Lewis base (weak base) react wit h acids to form
Ammonia erng ( lid)
NH 3 (gas) + HCl (gas) ~ NH4Cl so
NH 3 (gas) + HN03 ~ NH4N0 3
2 NH 3 (gas) + H2S04 ~ (NH4)2S0 4
of Nitrogen and Hydrogen.
Example 9. Give the reaction to prove that ammonia Is made up
Ans. 3Pb0 + 2NH3---4 3Pb + H20 + N2

Aqueous Solution of Ammonia

Ammonia is dissolved in water to from its aqueous solution.
NH 3 + H20 ~ NH40H
Ammonium hydroxide reacts with acids to form salt and water.
Ammonia + Acid ~ Ammonium + Water
(aq) salt
NH 40H + HCl ~ NH4Cl + H20
NH 40H + HN0 3 ~ NH4N03 + H20
2NH 40H + H2S0 4 ~ (NH4)2S04 + 2H20

Reaction of aqueous solution of Ammonia with soluble m.e tal salts

Ammonium Hydroxide reacts with soluble salts of metals to give insoluble precipitates of their respective
metallic hydroxides.

(dirty green)
insoluble
FeCl3 + 3NH40H ~ 3NH4Cl + Fe(OHb
Reddish Brown
(soluble)
Pb(N03)2 + 2NH40H ~ 2NH 4N03 + Pb(OH)2 -1,
white
insoluble
Zn(N03)2 + 2NH40H ~ 2NH 4N03 + Zn(OH)2 -1,
white gelationous
(soluble)
CuS04 + 2NH40H ~ (NH4)2S04 + Cu(OH)2
Pale Blue
(soluble)

if,::i Important
.,. The pale blue precipitate of Cu(OHh dissolves in excess of NH OH ti ·
soluble complex salt. 4 ormmg tertramine copper (/IQ sulphate, an azure blue

Cu(OHh + (NH4hS04 + 2NH40H ~ [Cu(NH3,}4)S04 + 4H20

Exampa. 10. Name the soluble precipitates formed by react· f .

Ana. Zinc Hydroxide, Copper Hydroxide. ion ° Ammonium hydroxide.

Test for Ammonia gas and Ammonium ion

• Ammonia gives dense white fumes with concentrated H d hl . .
Y roe one acid
NH3 + HCl ~ NH 4cl
• • reagent.
Ammonia gives brown colour or Precipitates with Nesslers
• When ammonia ~as is pas~ed through copper sulphate solution blue . . .
deep blue soluto1n on passing the gas in excess. precipitate 1s formed which changes to

r°rrr
426 t:::19 Educ'art ICSE Chemistry Class X
 te and
. . . 'd sodium carbona
. ely used .in the man ufac turin g of nitrogenous fert illze
uses nia is extensiv ro, nitri c ac, '
agent .
as a refri gera nt and as a clea ning
Arf1rf1° xplosives. Generally, it is used
other e
a like colo ur changes,
1cSE Sugg~stions . relat ed obse rvation
e stud ying any chapter, stres s upon
d observat1o~~base d ques tions. Whilre, etc.
eratu
,.. StU ~tion of precipitates, gase s temp
rorm tand the mea ning · of' relevan t obse rvat ions
. ·
' unde rs .
,.. ctice writing bala nced chem ical equa tions
,.. pro on the colo ur/ solubility of prec ipita tes form ed using reag ents
,.. r:ocus .
tions.
•ce answering obse rvat ion- base d ques
.,. p,-act1 es for facts and concepts.
are fl.ow diag rams, shor t note s, tabl
"h
dd fi .. ll
,..prep the Laws an e nttJons we wit the correct term s/ke y words·
,.. Learn

( OB JE CT IV E Ty pe Qu es tio ns )
lyin g high
5. Whe n dry NH 3 is liquified by app
Multiple Ch oic e Qu es tio ns [ 1 ma
rk]
pressure it is called
(Strictly for !CSE Sem este r II Exams) (a) liquid quic klim e
is:
1. The substance used for drying NH 3 gas (b) liquid NH3
(a) CaO (b) Ca( OHh (c) Nessler's reag ent
(c) MgO (d) Mg( OH h (d) Non e ofth ese
Ans. (a) CaO Ans . (b) liqu id NH3
is form ed by
Explanation: As amm onia do not
reac t with Explanation: Liqu id amm onia
on dry NH3 .
CaO app lyin g high pressure
ess is
2. The satu rate d solution of amm
oni a in wat er 6 ............... gas used in Hab er's proc air.
obta ined by frac tion al dist illat ion of
is ...............
(a) N2 (b) H2
(a) Uquid amm oni a
(c) Bot h (a) and (b) (d) Non e of the se
(b) Uquid quicklime
Ans . (a) N2
(c) Uquor amm oni a fort is d in Hab er's
Explanation: Nitr oge n gas is use
(d) Nessler's reag ent
process.
Ans. (c) liqu or amm onia forti s process is
Explanation: The satu rate d
solu tion of 7. The opt imu m pressure of Hab er's
or amm onia 200 atm
ammonia in wat er in kno wn as liqu (q) abo ve 130 0 atm (b) belo w
of these
fortis. (c) abo ve 200 atm (d) Non e
n and
3. The ratio by ~olu me of nitr oge Ans . (c) abo ve 200 atm
............ .. per atur e in
hydrogen in Hab er's process is Explanation: The requ ired tem
.
(a) 3 : 1 (b) 4: 2 Hab er's proc ess is abo ve 200 otm
(d) 2 : 4 of NH3
(c) 1 : 3
8. The pro mot er use d in man ufa ctur ing
Ana. (c) 1 : 3 is ...............
Explanation: (a) Mo lybd enu m (b) H203
se
N2 + 3H 2 ~ 2NH3 (c) Bot h (a) and (b) (d) Non e of the
4 The pun gen t ·sme ll whi ch one enc oun ters An1 . (c) Both (a) and (b)
• activity of
mat ter Is Exp lana tion : Bec aus e it enh anc e the
near a decaying hea p of org anic
due to: cata lyst .
aus e it is
(a) Cl2 (b) NH3 9. Am mom la is solu ble in wat er bec
(c) CO 2 (d) 02
(a) Pol ar mol ecu le (b) Bas e
Ana. (b) NH3
(c) Acid (d) Sal t
prod uce d by
Explanation: As amm onia is
Ana . (b) Bas e
bacterial dec omp osit ion.
•
Am mo nia ~ 42 7
 Explanation: In ammonia nitrogen have a lone An•• (a) Calcium Nitrat e
pair of electron. Hence it is a base. Explanation: When ammoniu n, hydr .
10. Ammonia turns moist turmeric paper ............... . dded t o calcium nitrate, no rea 0X1de
1s a . . . ct1on
(a) Red .c mot ion of prec1p1tate 1s seen. As am . or
(b) Blue 1or . . . rnon 11.j
(c} Brown (d) None of these hydroxid e is a weak aci d, it is very diffic n,
Ans. (c) Brown n the Of1 ions t o displace the NQ,;2 . Ult
or . t. ., ions in
Explanation: Because it is a base. calcium nitra e.

11. When NH3 is passed through CuS0 4 solution A or·Calcium Nitrate

................ precipitate is formed. [Marking Sche
(a) Blue (b) Green l'l'le]
(c) White (d) Red 'wJ. What Examiners say
Ans. (a) Blue ..,. Some candidates chose the salt copper nitrate .
. . Wn'1/p
Explanation: Others selected lead nitrate instead of colciunn . . ·
n1trot~
CuS04 + NH40H ~ Cu(OHh + (NH 4)2S04 6 Caution ·
..,. Read the question carefully and state comp/et,.,
12. Anhydrous NH 3 is .......................... answer ·
(a) Colourless (b) White
14. Nitrogen gas can be obtained by [ICSE 2
(c) Brown (d) Green 0131
(a) Ammonium nitrate
Ans. (a) Colourless
(b) Ammonium nitrite
Explanation: Anhy. ammonia is colourless. (c) Magnesium nitride
13. The salt solution which does not react with (d) Ammonium chloride
ammonium hydroxide is: [ICSE 2018] Ans. (b) Ammonium nitrite
(a) Calcium nitrate Explanation:
(b) Zinc nitrate (NH3 + HCl~ NH4Cl)
(c) Lead nitrate Dense white fumes
(d) Copper nitrate

( SUBJECTIVE Type Quest ions)

Fill in The Blanks [ 1 mark ] Explanation: Ammonia react with chlorine tc
give ammonium chloride
15. The molecular mass of ammonia is ...............
NH3 + Cl2 ~ NH4Cl
Ans. 17
Explanation: Molecular mass of ammonia 19. Industrially, ammonia is synthesized by
............... process.
= NH 3
Ans. Haber's
= (1 X 14) + (3 X 1)
Explanation: Industrially ammonia is for111ec
= 17 by Haber's process
16. Ammonia is ............... in nature due to presence N2 + 3H2 ~ 2NH3
of _ __
Ans. Basic, lone pair of electrons 20. Ammonia gives dense white fumes with
Explanation: The compound which have lone ··•• .•·········
pair of electrons are basic in nature. Ans. Cone. HCl
Explanation: NH 3 react with HCl t o give dense
17. Liquor Ammonia fortis is a saturated solution white fumes of ammonium chloride
of .............. .
NH3 + HCl ~➔ NH4Cl
Ans. NH40H 21• ............... on reaction with water gives
Explanation: When ammonia is dissolved in ammonia.
water it result in formation of ammonium Ans. Nitrides
hydroxide known as liquor ammonia fortis.
Explanation: Nitirides react with water given
18. Excess ammonia reduces chlorine to ............... ammonia.
Ans. NH4Cl 22 • Ammonium salts reacts with ............... to
liberate ammonia.
0

428 ldl!JJ Edu c'a rt ICSE Chemist ry Class X

 11 1 ." 1
'
(iiO
(,di1 (v) (e) -- q
-
I'
r
-
Ana. (a)- (iv), (b) -(0, (ch 1 column (JI)
Alkalis •
J.f1S• ~planat1o n: Column (I)
30 .
NH 4Cl + Na OH ~ NH 3 + Na Cl + H20 (I) NH4 Cl /
(a) Lewis ba se
/
A ,nonium compounds are ............... 1n wa ter (b) Dense wh ite (ii) N02
1,9• ,...m
fumes (Iii) NH 40 H
50 /uble .
J.flS• mo nia is sol ubl e in (iv) Colourless 1
~planat1on: Because am (c) Reddish bro wn
water gas (v) NH3
due to the bac ter ial (d) We ak basic
1,4. p.,nmonia . i~ profduced..... __;
decompos1t1on o .......... (e) Phenolphthalein
, (e) -(iv)
Urea (NH 2CO NH :;) Ans. (a)-(v), (b)-(0, (c)-(i0, (df-(ii0
,,_ns, duc es am mo nia by
~p lan ati on : Ure~ . pro pe Qu es tio ns
bacteria decomposrtron. Ve ry Sh or t An sw er Ty
nia is used as [ 1 ma rk ]
... ............. solution of liquor am mo
25 a Laboratory rea gen t. rin g Ha be r's process.
31 .Na me a cat aly st used du .
ing Ha be r's pro ces s is iron
t,..ns. Dilute Ans. The cat aly st used dur H
n of am mo nia is Fe/M o
Explanation: Dil ute sol utio N2 + 3 H2 2oo atm 4so c 2N 3 0

used as lab ora tor y.

26. Ammonia is collected by _
__ m sa lt used for
32 . Na me the Am mo niu
m.
Ans. dow nw ard dis pla cem
ent of air pre par ati on of alu mi niu
hea vie r tha n air. niu m sul pha te is use d for
Explanation: Becaus it is
e Ans. (NH 4), S0 4, Am mo
.
excess chlorine to pre par atio n of alu min ium
21. Ammonia reacts wit h wly wit h mo ist ure to
/ni tro gen tric hlo rid e/ 33 . A fertilizer tha t rea ct slo
form - - - .. (ni tro gen [ICSE 201 9]
ammonium chloride) give NH3.
2NH3 + Ca C0
Ans. Nitroge n tric hlo rid e
(NCl:J)
1 K An s. CaCN 2 + 3H 20 ~
co.:,,,S"i-S
:-':\?~!'%1 ma nu fac tur ed by
:..

34. A compound which is

·
·
l ..
Nit rog en tnc hlo nd e or NC 3
·

[M a rid rig'; Sch \lii(~ft:

) 1-..~v,,.t·~~◊?>}t~~~ oxidation of am mo nia .
~ : ~~:-

+ 6H 20
,- ,, )..
',_

4N H3 + 50 2 ~ 4N 0
"' "

Ans.
'f7J What Examberineofrscansadid
y
ate s did not sel ect the
2N 0 + 02 ~ 2N 02
._. A larg e num N0 2 + H2 0 ~ HN 03
correct option. ba mo xid e
ted by .............. (an 35 . The co mm on na me of car
28. Ammonia gas is collec na me of ca rbo mo xid e.
a do wn wa rd
of air, An s. Ure a is the com mo n
upward dis pla cem ent wh ich is exp los ive .
do wn wa rd
displacement of wa ter , a
36 . Na me one sa lt of am mo nia
[ICSE 201 4] N0 ).
displacement of air ).
Ans. Am mo niu m nitr ate (NH 4 3
en t of air. wh ich is us ed as
Ans. Do wn w ard dis pla cem 37 . Na me one sa lt of am mo nia
of air medicine.
Do wn wa rd dis pla cem ent Cl) is use d as me dic ine.
[Marking Scheme] Ans. Am mo niu m chl ori de (NH 4
dir ect ly co mbine s
~ Wh at Exa mine rs sa y 38 . Na me the me tal wh ich ng .
XI- wit h nit rog en on he ati
this que stio n correctly.
,.. Most condidate s ansvvered An s. Ma gen isu m, Ca lciu
m, Alu min ium
Ex pla nat ion :
Match th e Fo llo wi ng 3M g + N2 ~ M g3 N2
[ 1 ma rk ]
3C a + N2 ~ Ca 3N 2

Co lum n (II) 6A l + 3N 2 ~ A lN
29. Co lum n (I) /
ne d wh en Mg 3 N 2 is
39 .Na me the ga s ob tai
(a) Am mo nia / (i) Pro mo ter
wa rm ed w ith wa ter.
(b) Mo lyb de nu m ' (ii) Ca tal yst
Ana. NH 3
' (c) Iron (iii) Dry ing ag en t
Ex pla na tio n:
(d) 880 am mo nia (iv) Colourless
M g 3N 2 + H20 ~ Mg
(0H)i + NH 3
(v) Liquid am mo nia
(e) Quick lim e
l for its
0

Am m on ia ~ 42 9
 ..a11 N the ex.perIme nt which de mo ns trates An,. Pla tinum
"'"'• am e .
the extreme 5 olublllty of Ammonia.
. exp· eriment is done
Ans. Fou ntain Platinum or Pt.
t o prove t ha t NH3
is soluble in wa t er.
[Marlclng ~
,41 . Name the soluti on
wh ich turns brown when ~ What Examiners say
it comes In conta ct wi
th ammonia . -. Mo st condidates identi
Ans. Nessler's reagent fied the catalyst used
t urn s brown by ammonia Ammonia correctly. Ho
. wever, a few to 0xidlae
42. Name mentioned incorrect cataly
tw o ga se s wh ich °
st such as FefV c 11did~
fumes with ammonia
.
give dense white
& Caution 20 s/Coo

Ans. Chlorine, Hydro -. Ma intain a comparative

gen Chloride gas chart for the various
consisting of reactants
Explanation:
..
, catalysts, temProece8Iles
pressure, con d1t1on, equati.on etc. p rotu re/
NH 3 + HCl ~ NH
4Cl
NH3 + Cl2 ~ NH
SO. Name the gas evolved
4Cl when Ammonia 'eacta
with heated copper oxide
43. Name an orange . [ICSE 20t9
compound which on Ans. Nitrogen (Ni)
heating erupts with 1
green mass in the for
of volcanos. m
Ans. Ammonium dic
hromate (NH hCr2O
4 7 is the
compound . & What Examiners say
44. Name the compound _,. In the reaction of ammo
nia
reacts with
formed when nitroge
n the gas evolved was inc with heated copper oxide
calcium carbide. orrectly written as N, NO
N02, ~
0
Ans. NitroUm
Explanation:
51. Why Ammonia and
ammonium compound
do no
t occur as minerals? s
CaC2 + N2 ~ CaCN
2 +C Ans. Ammonia and am
mo niu m compounds do not
(Nitrolime) occur as minerals
because they are
45. Name tw o metallic ox soluble in water. highly
ides which are reduced
by ammonia.
52. State the condition
Ans. Copper oxide an required for Catalytic
d Liead oxide oxidiati on of ammonia to nit
Explanation: ric oxide.
Ans. Platinum catalys [ICSE 2014]
3CuO + NH3 ~ 3C t, temperature of B0
u + N2 + 3H2O 0°C.
3PbO + 2NH3 ~ Explanation:
3Pb + N2 + 3H2O
46 . State the tempera 4NH3 + 50 2 Pt ) 4NO + 6H2O + Hea
ture at which Habe 1 800°C t
process rs
is carried out.
Jvt.&. Th e optim um
temperature is betw
een 450 -
500°C

47 . Whk:h type of rea

ction takes place wh ~ What Examiners say
ammoniu en _,. Catalyst incorrectly
m dichromate is heate mentioned as Fe or ,vfo
d? or
J,;,ns. The he at is evolved . temperature at 250o/450°
Hence, reaction is C
exother mic.
53. Nitrogen gas can be
obtai ned by heating:
48 . Name the ga s evolv
ed when sodium nitrite Is [ICSE 2013]
treated with ammoniu Ana. Ammonium Nitrit
m chloride. e
Ana. Nitrogen Explanation: NH NO
4 2 ~ N2 i + 2H20
Explanation: 54. Name the gas pr
oduced when excess
NH4 Cl + NaN02 ~ ammonia reacts with
N2 + 2H2O + NaCl chlorine. (ICSE 20121
49 . Identify the catalyst Ana. Nitrog en tric hlorid
used to oxidise amm~nla
e
. Chemical Equation:
[ICSE 2019]
NH 3 + 3Cl2 --- 4 NCl + 3HCL
•
430 ~ Edu(:'art
3

ICSE Chemistry Clas

sX
 • .1 gnesium nitride reacts w 'th
. 1 Water to
~o~u~~:
t. ,v,a
S:1• 'berate ammonia. [IC Inky blue solution/deep blue ~; ,
U . . SE 2012]
lAagnesium rntnde reacts with boill formed/azure solution/t he precip t '•t te
,. 1v1
• ng Wat er to blue prec:ipltate or pate blue prec1Pl a
II' [ilberate ammonia. · · ·tat e or
dissolves or is soluble/t he pncrp1
0

[ 1 mark ] blue precipltate or pale blue precipitate,,

,tate the Observation (dissolves) forms inky blue/deep bloe
Ammonia comes in contact with solut ion.
56• concentrated HCl. [Marki_ng SchemeJ
oense white fumes are observed.
ArtS- ~ What Ex~miners say
57, Ammonia_ is passed over heated copper oxide. -. Some candidates did not write the solubility of the
Aris, Copper oxide changes to black pink in colour. blue precipitate in excess of ammonium hydroxide;
instead of writing deep or inky blue solution some
8, Ammonium dichromate is heated. wrote "deep blue precipitate is formed."
5
Ar,S, The reaction is exothermic which result in 67 • Ammonia gas is passed over heated copper
release of heat. (II) oxide. (ICSE 2019]
Ans. The black coloured copper (II) oxide turns into
59, excess of chlorine gas is reacted with
reddish pink substance.
Ammonia gas.
Chemical Equation:
AnS- The greenish yellow colour disappear.
3Cu0 + 2NH 3~3Cu + N2 + 3H20
60, Afew drops of dilute HCl are added to AgNO3 (; ,, '"> , ; , •,,/,1/)/'ff~v.:,.;~:• r, •~v • / 1

· , The pJac~ sopp~.r (t)rOxkfe turns into o pink

solution, followed by addition of NH 4OH
:,,' ;qr~reitldisl: {!1t,d,0 Fil1sUb.sta'Ace. , 1
solution. -~~~:✓ :%:i}, <':L, ,<~:0; ~,,;: :::ffl>/:, /;: ,:/ .
,~~·, /'0"','i/';t}}:!<;;"/ ufh.f'{~ / t ,:,[Marking Scheme]
/

AAS- White precipitate appears which is soluble in 9t:f.<}:,t,,. ·-':~?:_r,.c1,I>;>j;·~_,5,;,fr,\,0<,/,; ~~ ; ·/. · / - ,

excess of NH40H. wJ, What Examiners say
-. Several candidates incorrectly wrote the colour of
61. When ammonia gas is burnt in an
copper as red or reddish or brown.
atmosphere of excess oxygen.
Ans. Green flame is produced. 68. Burning of ammonia in air. [ICSE 2017]
Ans. On burning ammonia in air, yellowish green
62, Excess of ammonia is passed through an flames are observed.
aqueous solution of lead nitrate.
AnS. White precipitate is observed which is insoluble ~~~~> ~~
in excess ammonia. ;~\'.)i\_[Marking Scheme]
" :·, \~t\):.._~-t}, \''' '

63, Glass rod dipped in NH 4 OH is brought near wJ., What Examiners say
the mouth of concentrated HCl acid bottle. -. Many candidates could not write the correct colour of
Ant. Dense white fumes of ammonium chloride is the flame on burning ammonia.
observed. 69. This gas produces dense white fu mes with
64. NH40H is added to aqueous solution of FeSO4 ammonia gas. [ICSE 2015]
Ans. A Hydrogen Chloride gas produces dense
Ans. Dirty green precipitate of Fe(OHh is formed.
white fumes with ammonia gas.
6S, NH40H is added to Lead nitrate solution.
Explanation:
Ant. White precipitate of Pb(OHh is formed. NH 3 + HCl~ NH4Cl
66• Addition of excess ammonium hydroxide into (wh ite fumes)

~ copper sulphate solution. [ICSE 2020] " ,··

Hydrogen Chloride ~\ \ ' \:

'· When excess ammonium hydroxide Is added to

[Marking Scheme}
0
: PPer sulphate solution, a pale blue precipitat e
16
' -' '
obtained which dissolves forming deep blue
solution.
Jt:i] What Examiners say
-. Most candidates answered correctly. A fe w mentioned
thernical Equation:
ammonia, perhaps in haste.
Cuso4 + 2NH40H ~ Cu(OHh + (NH4)2
70. When calcium hydroxide is heated with
S0 4 + 4H20 ammonium chloride crystals. (ICSE 20141
Cu(OH)i + (NH 4)2 S0 4 + 2NH40H Ans. When Calcium hydroxide is heated with
~ [Cu(NH3)4]S04 + H20 Ammonium Chloride crystals then a colourless

Ammonia
rrrr
CdB 431
 L\
H) + 2NH4Cl ~ CaCl2 + 2H 0
An•• ca (O 2 2 + 2NH
, ) 1 valved . 3
gas with smell of ammo nia (NH 3 s e nium nitrite is heated.
j 8 1• Amm o
Chemical Equation:
3 NH 4N02 ~ N2 + 2H20
Ca(OH)i + 2NH4C l~ CaCl 2 + 2H20 + 2NH
An••
r sulphate solution is add d
82 coppe e to
Gos with pungent odour evolved
Scheme] • amm onium hydroxide solution.
(Marking
An•• c uS0 4 + 2NH40H ~ Cu(OH)i + (NH4h so4
~ What Examiners say .
• The products such as calcium chloride and t '~
amm 83
• Amm onia is prepa red from its elements.

were listed instead of incorporating the sme

1 0 Fe-Mo ,
2NH 3
Ans. N2 + 3H2 ..- 4so-soo c
0

ammonia or any test of ammonia. 200atm

71. Excess of chlorine gas is reacted with
[!CSE 2013] Rod dipped in cone. HCl is brought in contact
84•
ammonia gas.
Ans. Yellow colou red explos ive (NCl3) Nitrogen with ammo nia.
t richlo ri de is forme d. NH 3 + HCl ~ NH4Cl
Chemical Equation: Ans. (Cone)

NH3 + 3Cl 2 ~ NCl3 + 3HCL

85. Lab preparation of ammonia using
(Excess)
ammonium salt.
72. Ammonium hydroxide solution is added to L\
copper (II) nitrate solution in small quantities Ans. 2NH 4 CL + Ca(OH)2 ~ CaCl2 + 2H 20 + 2NH 3
and then in excess. [ICSE 2013]
86. Reactio~ of excess amm onia with chlorine.
Ans. A light blue precipitate is formed on addition [ICSE 2020]
of excess of Ammo nium Hydroxide which
dissolves giving a inky blue solution. , ,¥ f, ,'. ~ '-, } ~. ,; ,

73. Ammonium hydroxide solution is added to f J6Nr:l4,P + N2 ,

zinc nitrate solution in minimum quantities jf ,[Marking Scheme]
and then in excess. (ICSE 2013]

Ans. A white precipitate is formed which dissolves

)vJ Wha t Examiners say
in excess of Ammo nium Hydroxide.
"'+ Some condidates wrote the products with excess
Chlorine as NC1 3 and HCL.
Give the balanced Chemical Equation ~ Caution
[ 1 mark ] "'+ Insist upon practicing chemical reactions ofacids witr
metals and non metals under different conditions.
74. Ammonium chloride is treated with sodium s.
"'+ Understand the logic ofbalancing Chemical equation
hydroxide. Writing ofequations should be practiced.
Li
Ans. NH 4 Cl + NaOH ~ NaCl,+ H2 0 + NH 3 87• Reaction of lead nitrat e solution with
ammo nium hydroxide. [ICSE 2020]
75. Magnesium nitrite is treated with warm
water. Ans. Pb(N03}i + 2NH 4 0H ~ Pb(OHh + 2NH4NO:
Li
Ana. Mg3N2 + 6H20 ~ 3Mg(OH)i + 2NH 3

76. Aluminium nitrite is treated with water.

Ana. AIN + 3H20 - - t Al(OHb + NH 3
77. Ammonia is oxidized by a metal oxide.
Ana. 3Cu0 + 2NH 3 ~ 3Cu + N2 + 3H 20
78. Ammonia reacts with chlorine gas.
Ana. NH 3 + 3Cl2 - - t NCL3 + 3HCL
79. Ammonia reacts with lead oxide

Ana. 3Pb0 + 2NH 3 ~ 3Cu + N2 + 3H20

80. A mixture of Ammonium chloride and slaked

lime is heated.

432 i;JfJ Educ 'a rt ICSE Chem istry Class x

r

r0J
wt
What Examiners soy
A large number of condidatos
,e rormu Ia or ammonium' fn,.Odo 1)1rorti In w, 1,1
A"•· /\ Mn1N, "6H10 - • 3Mg(OHh + 2NH3
tl 111
5lllp·
/10te. In sevrra l cosns, l'Qll" t /'' Phllt (, o, fhn ,,nq 98 • Reduction of hot copp•r (II) oxide
to eo9per
"' 0 1') Wn ~ 11/l
, not ho/cinrnc/ using ommonlo goi. ·
Reoctlon of Ammonia With h (ICSE 2013)
6'• 0~1de, Gated copper A"'• 'J C 110 ,, ?NH 1 ~ 3Cu _., 3H20 + N11
3cuO ➔ 2NH3 Pt ➔ 3Cu + 3H... o
PNa E~1 7] 99 • Ammonlo and mcyg• n In 01e pr ~ of a
~,,.. - -~ ; + ') catalyst . {JCS£ 2012]
9CUO + 2NHs ➔ 3tu + 3H2o + N
2 Ana. 4NH 3 + SO;, 4NO + 6H10
[Marking Scheme) 800"C

~ What Examiners say Cive Reason

~ ,. some cond'd
[ 1 rn~rv J
· instead f
, ates wrote N02
roduct while in some cases the e
O 2
. N as the lOO. Why Ammonia and ammonium c o ~
P quat,on w
balanced correct ly. as not do not occur as minerals?

,o. catalytic oxidation of Ammonia. [ICSE

20171
Ans. Ammonia and am monium compounds beir;g
Pt highly soluble in water do not occur as rniner a~.
,.,.s. 4NH3 + 50 2 8000c ➔ 4NO + 6H2o
l 0l. Why liquor ammonia fortis is known as 880
Pt ammonia?
4NH3 + 502 700 - aoooc ~ 4NO + 6H2O
Ans. Liquor ammonia fortis is known as 880 because
[Marldng Scheme] it has a relative density of 880.

102. Why ammonia gas is collected in inverted

W-J What Examiners say
gas j ars by the downward displacement of
,. ~~-ny candidates wrot e t he product as No 2 instead of
air?

91. Reaction of Ammonia with Nitric acid. Ans. Ammon ia gas is collected in inve rted gos jars
by the dow nward displacement of a ir beca use
[ICSE 2017]
it is lighter t ha n a ir a nd it is highly soluble in
water. Hence, it cannot be coliected over water.

103. Why the mixture of ammonia and oxygen is

[Marldng Scheme]
dangerous in nature?

~ What Examiners say Ans. Mixture of ammonia and oxygen is explosive

.. Most of the condidates answered correctly. A few got and therefore it is dangerous.
confused with the formula of ammonia as NH,i.
104. Why liquid ammonia is used as a , efr igewant
n. When excess of ammonia is treated with in ice plants?
chlorine. [ICSE 2016] Ans. Liquid ammonia takes a lot of energy to va po rize.
tins. 8NH3 + 3CL2 ~ 6NH 4 Cl + N2 This heat is taken from the surrounding bodies
which are conseqL1ent ly cooled down
!3. kit eq,1,;ation to illusrate the reducing nature
of ammonia. [ICSE 2016] Moreover, ammonia is environmenta lly
compatible. It does not deplet e ozone layer and
Iv., 3CuO + 2NH 3 ~ 3Cu + 3H20 + N2
does not contribute towards global 'NCffiltng.
&4. Lab preparation of ammonia using an
kri ~mmonium &alt. [ICSE 201 5) 105. Why ammonia solut ion is used as on
. ~ LNH4Cl + Ca(OH)i ~ CaCl2 + H20 + NH3 important laboratory reagent?
Ana. Ammonia is used as an importa nt laboratory
ts. Rea...- uon
· of ammonia with excess ch Lo rlne.
reagent beca use it gives characteristic coloured
[ICSE 2015)
m etallic h~droxides precipitates.
..... ,~H j + 'j Cl , -1 3HCl + NCh
106. Why aqueous ammonia Is used for cleaning
9'. Reaction of ammonia with sulphuric acid.
tllH, windows etc?
[ICSE 2015)
Ana. Aqueous a m monia is used fur clea ning t iles.
' 2NH
' 3 + N,S04 --1 (NH4hS0 4 w indows beca use it emu lsifies or dissolves futs,
) • Acti
on of warm water on magne1lum nitride. grea ses etc.
[ICSE 2014)
•
Ammonia T'I ! 433
l:::Ja
107 . Why aqueous solution of amm onia
gives a 114• Nam e a com poun d prep ared by an,l"rlo,r
pungent smell? and is used as
ici
Ans. Ammonia is formed by bacterial deco (A) Explosine
mposition (8) Fertilizers
of urea, therefore, ammonia has a
pung ent
smell. (C) Med icine (D) Laboratory rea
. .
108 . Why aque ous solution of ammonia cond Ana. (A) Explosive- Ammonium nitrate (NH N 9ent
ucts 4 0)
electricity? (B) Fertilizers- Ammo~ium nitrate (NH N 3
)
4
Ans. An aqueous solut ion of ammonia (C) Medicine- Ammonium carbonate (NH )0 3
is a weak
electrolyte. It dissociates partially
to give (D) Laboratory reagent Ammonium H, 'd4 2C03
.
hydroxyl ions and ions conduct elect :, rox1de
ricity. (NH40H)
109 . Explain why ammonia gas is evolved whe
n llS . During labo rato ry preparatioh how
wat er is added to the product formed is
when
Magnesium is burnt in the air? ammonia dried and collected?
Ans. When Magnesium is burnt in air, An ~ Du ring laboratory preparation of amrnon· .
it forms
magnesium nitride which on warm ~ ~
ing with is passed through a drying tower
wate r produces ammonia containin
quick lime (calcium oxide). It is collec 9
ted
3Mg + N2 ~ Mg3N2 downward displacement of air.. 6y
Mg3N2 + 6H20 ~ 3Mg(OHh + 2NH3
110 . This gas is used as a reducing agen 116. Certain blank spac es are left in the following
t in tabl e and thes e are labelled as A, B, C Identi
reducing copper oxide to copper. fy
each of them .
[ICSE 2015]
Ans. Ammonia gas is used as a reducing
agent in
reducing copper oxide to copper. Method
of
Explanation:
collection
NH 3 gas
3Cu 0 + 2NH 3 ~ 3Cu + 3H20 + N2 A Mg(OHh B I C
+NH3 ...............
I
I ............_
Short Answer-I Type Questions
[ICSE 2017]
[ 2 mar k] Ans. (A) NaHS0 4 + HCl
111 . Name the common refrigerant. How does (8) Quick lime
it (C) Upward displacement of Air
deplete ozone layer?
Ans. CFC (Chloro Fluoro Carbon) is
the common ";f.:ztl';o,
refrigerant. At deplitic earth's atmo
ozone layer, the ozone layer is depletiat
spheric ,,-':a"~
or Cao
ed as it 'I;i~ ard·d1sglacement of air
release chlorine atoms which react with
molecule and break them.
ozone t;:,:( "~ , ·
tl&.iti, >. ' , .. \.. ,,. ' ,.,,.. ,. "~,
[Marking Scheme]

112 . What is the alternative form of chlorofluo

ro
~ What Examiners say
carbon? ~ For A. some candidates wrote ammonium chloride
and alkali or Mg(N0:3) and water instead of
Ans. Modern refrigerators usually use the 2 Mg/(
refrig erant and H20.
called 1, 1, 1. 2-titrafluroethane. Besid
es this ~ For B, many condidates wrote Slake
d lime/Soda lim 2
Ammonia is the most environmenta concentrated H2S0 4 instead of quicklime or
lly friendly CaO.
~ For C, pertaining to method of collec
refrig uant used . tion of NH3gas._
some condidates wrote downward displa
cemen~
113 . A gas •p• gives dense white fumes with downward displacement of water, wh1. h were
c
incorrect answers.
chlorine. Its aqueous solution gives
blue
colour with Cu(OH)i.
(A) Name the gas P
&~ Cau
Unde
tion . . e and
rstand the reaction between metal nitri d
(8) Give its formula. H20 fielding metal hydroxide and ammonia.
~ P d
.
ay attention .
Ans. (A) Ammonia to the basic nature of am monia anuick
hence the use of a basic brying agent such
. . as q
(8) NH 3 lime and not an acidic one like concentratedH2S04·
~ f
NH + Cl ~ NH Cl (den se white Correlate the knowledge of density and l~~ o
3 2 4 fumes) so u 05.
gases in deciding the method of collection of th 9
e
0

434 l$a Edu ~or t ICSE Chemistry Class X

 Nome the gas evolved \/\th
ii1• ,r1i,ctures are
heat ed: en t h8 following
-
Ana.
(A) calcium Hydroxide and Equation 1

Chloride. Ammonolum Name for the

of'tho Tompo ra ◄ Cowti11t cotal¼,z.ed
sodium Nitrite and Am turo
(13) monlum Chl0rlde procHa 1 rerJct1on
1
Haber's 4SO SOO" I Hnely · N? + 3H? _.
s. (A) Am mo nia gas is evolved. [Iese 2016] : 2NH 1 + Heat
process I divid ed
Art Explanation: , Iron (Fe)

ca(OHh4 + 2NH4Q ~ Caa 2N

Short Answer-II Type Question s
2+ H3 i + 2H
(13) Nitrogen gas is evolved. 20
[ 3 mark]
Explanation:
121. The following questions a re related to the
NaN02 + NH4Cl ~ NaCl + N
2 1 + 2H 2o manufacture of ammonia.
(A) Name the process.
S. iron OI) sulphate and iron (Ill) sulph .
i1 . h . ate (usmg (B) In what ratio must t he reactants be
ammonium ydrox1de). [ICSE taken.
2014]
Iron (II) Sulphate on reacting with a . (C) Name the catalyst used.
Af!S, . . . mmon1um
a di rty green prec·i •t (D) Give the equation for manufacture of
1,ydroxide gives Pl ate of
ammonia.
Fe(OH)2.
(E) Ammonia can act as reducing agent.
FeS04 + 2NH40H ~ Fe(OHh + (NH 4h so Write a relevant equation for such
4
dirty green reaction.
.
Iron (Ill) sulphate on rnucting with amm onium Ans. (A) Haber's Process
hydroxide gives a redciish brown precipitate (B) 1: 3
of Fe(OHb (C) Finely divided iron
Fe2'S04)3 + 6NH40H ~ 2Fe(OH)3 + (D) N2 + 3H2 Fe.MO 2NH3
4SO-soo c 0

Reddish (200)

brown 6.
(E) 3Cu0 + 2NH 3 ~ 3Cu + N2 + 3H2 0
3(NH 4hS0 4
122. (A) How would you obtain compound
119, A lead salt and a zinc salt (using excess
Mg(OH)i?
a~ monium hydroxide). [ICSE 2014]
(B) Which property of NH3 is illustrated by
Ans. A lead salt on reacting with NH 40H gives reaction:
a white precipitate insoluble in excess of 3CuO + 2NH 3 3Cu + N2 + 3H 2 0
~

NH40 H solution. (C) What is the name important industrial

of
Pb 2+ + 2NH40H---- -? Pb(OH)2 + 2NH4 + process that start with reaction
white 800°C
NH3 + 02 ---➔ NO+ 6H2 0
ppt.
and name the catalyst used.
A zinc salt on reacting with NH 40H gives a
(D) How is ammonia dried and collected?
gelatiuous w hite precipitate which dissolves
in excess of NH 40H.
Ans. (A) By introducing burning Magnesium in j or of
nitrogen.
Zn2+ + 2NH 40 H-----? Zn(OH)2 J, + 2NH4 +
(B) Reducing property
(white soluble) (C) Ost wald 's process for manufacture of Nit ric
UO, Copy and complete the following table acid. The catalyst used is platinum.
relating to important industrial process. (D) Ammonia is dried by passing through quick
I line and collected by downward
I Equation
Name fortha displacemen t of air.
I ~ofthe Tempera• Catalyst I catalyzttd

~::rw~ J
Process
1 -
reQetlon
123. (A) Though Ammonium nitrite readily gives
nitrogen on heating a mixture of
ammonium chloride and sodium nitrite
In water Is heated to prepare nitrogen in
[ICSE 2013) the laboratory
0

f'I!_ 435
Ammonia l:::fllJ
 en chloride gas (Blue litmus is u ,
A) HY d ro g . . sed)
d ver water. An•• ( e solubility 1n water
be co LLecte o (B) Extrem .
(B) Ammonia can't
. ·t
d even
(A) Ammonium n1tn e conn ot be store (C) Ammonia
. . is
Ans. at room tempertaure, therefore, n1troge~d the following conversions tarr'
obtained by heating ammoniu · m chlon e 12 7• HoW are
t1 Give equations on y.
L 1ed
OU B C
and sodium nitrite. l ble
(B) Ammonia is highly or extremely so u d NH3 ~ NO ~ N02 - - , HN03
(A) D
in water, and therefore, it is not collecte
~ Cu(No h
3
over water.
(B}
124. (A) In the two gases, Ammonia and Hydrogen
chloride, w hich is more dense? Name th e
method of collection of this gas?
(8) Give one example of a reaction between
the above two gases which produces a
soUd compound.
(C) Write a balanced equation for a reaction
in which ammonia is oxidized by
(1) A metal oxide
(2) A gas which is not oxygen.
Pt
Ans. (A) HCl gas, it is collected by the upward Ans. (A} A: 4NH3 + SO2 800°C 4 NO + 6H20
displacement of air as it is denser than air.
(B) NH3 + HCl~ NH4Cl
B: 2NO + 0? ~ 2NO2
(C) (1) 3CuO + 2NH 3 ~ 3Cu + N2 + 3H2O
(2) NH3 + 3Cl2 ~ NCl3 + 3HCl C: 4NO 2 .. 2H2O + 02 ~ 4HNO3
125. (A) Which feature of the ammonia molecules D: CuO + 2HNO3 ~ Cu(NO 3h + H o
(excess) 2
leads to the formation of ammonium
ion when ammonia dissolve in water? (8) A: 8NH
3
+ 3Cl2 ~ 6NH4Cl + N2
(B) Name the other ion formed when (excess)
ammonia dissolves in water.
(C) Give one test that can be used to detect B: NH3 + 3Cl2 ~ NCl3 + 3HCl
(excess)
the presence of hydrogen ion.
Ans. (A) Nitrogen in ammonia has a lone pair of
C: NH3 + H2O ~ NH4OH
electrons which leads to the formation of
Ammonium ion.
D: 4NH3 + 302 ~ 2N 2 + 6H2O
(B) Hydroxide ion
(C) It turns red Litmus paper blue. E: N2 + 3H2 ~=F=e-=M=o=== 2NH3
200-l000atm
126. Study the figure given below and answer the 4so c
0

following questions:
F: 3 Mg + N2 ~ Mg3N2
Spray
GasY G: Mg3 N2 + 6H2O ~ 3Mg(OH)i
LUu...r-- - Dropper + 2NH3
(C) A: NH4Cl + NaOH ~ NaCl + H 0
2
+ NH3
Water
+ Blue B: 8 NH3 + 3Cl2 ~ 6 NH 4Cl + N2
Litmus
C: NH3 + H2O ~ NH4OH
(A) Identify the gas Y.
(B) Which property of gas Y does this D: CuSO4 + 2NH4OH ~ Cu(OHh
experiment demonstrate? + (NH 4)2S04
(C) Name another gas which has same 128
• Co~y a nd complete the following table
property and can be demonstrated by which refers to the industrial method for the
same experiment preparation of am • · 'd•
_ moma and sulphuric ac1 ·
0
 ar e ba se d th on
. ·n e
. qu es tio nsrn on ia ga s 1

tic eq ua - 13 0. The foep llo wi ng

I N am eo ft he Ca tanly(w ith th e of ar n
th e pr ar at io n
proces s tio . ni tr at e is no t
ca ta ly st) la bo ra to ry : ni a.
moniurnof ar nr no
.... .... .. . .... .... .. . (A ) Explain wh y amar at io n
(A ) .... (B) .... used in th e pr ep
11 .. us ed as
[ICSE 20 19 ] m po un d no rr na ~
(B) Na m e th e co
rin g th e process.
es s a dr yi ng ag en t du
(A) Haber's Proc ed ?
Fe
on ia ga s co lle ct
~r,s.
3 K O+ At o ► 2NH3 (C) Ho w is am m ov er
(8) N2 + H2 2 2 3 ·1s no t co lle ct ed
n to wh y it
ed ch e? 1i ca l eq ua tio (0 ) Explain [ICSE 20 12 ]
zg. (A) Write th e ba la n~ ga s 1n th e la bo ra t
prepare am m on ia or y wa te r?
$ is an ex pl os ive
by using an al ka li. s. (A ) Am m on iu m ni tra te
is An it de co m po se s
wh y co nc ~n tra te d su lp hu ric acid su bs ta nc e an d on he at in g
(B) Stute .
ng am m on ia gas. an d wa te r va po ur
no t used fo r dr yi in to nit ro us ox ide
lle ct ed ov er + 2H 20
on ia ga s no t co NH 4N 0 3 ~ N2 0
(C) Why is am m [ICSE 20 18 ] be ca us e th er e
wa te r? (B ) Qu ick lim e (CaO), th is is us ed
2H 20 + 2NH3 ee n Ca O an d NH
3.
(OH)i ~ Ca a2 + no re ac tio n be tw
AflS- (A) 2NH4a + Ca be us ed is
rd
su lp hu ric ca nn ot ct ed by do wn wa
(B) Co nc en tra te d s as it re ac ts wi th (C ) Am m on ia ga s is co lle
ia ga
fo r dr yin g am m on ai r.
g am m on iu m su lph at e. di sp la ce m en t of
fo rm in an d
am m on ia so lu bl e in w at er
(D ) Am m on ia is hi gh ly te r.
n:
Chemical Eq ua tio am m on ia ov er wa
so we ca nn ot co lle ct
(N H4 h S0 4.
2NH3 + H2 S0 4 ~
ov er wa te r
is no t co lle ct ed
(C) Am m on ia ga s
bl e in wa te r.
as it is hi gh ly so lu
 NITRIC ACID a
1TOPIC1 I
EARANCEAND STRUCTURE
P
PHYSICAL AP l
. ,, The mo ecu
lar formula of nitric acid is HN03- It
"aqua fortIs .
Nitric acid is a mineral acid, which is also known als o ordinate bond.
l b nd as wel as c -
is a compound w hich bears cova ent o
0

HN0 3 - H-0-N
/
'\Jo
(Bond structure)

Th e molecular mass of nitric acid is 63 · ) (3 x. 16)

HN03 = (1 X1) + (1 X 14 +
=1 + 14 + 48 =63
· acid .
Ex:a~ ~J~ '-_! Calculate the molecular mass of ni'tnc
~Se Molecular mass of Nitric Acid
HN03 = (1 x 1) + (1 x 14) + (3 x 16)
= 63

Discovery . .
frst prepared by 'Glauber. He prepared 1t
Nitric acid is commonly called as 'Aqua Fortis', i.e. strong water. Itwas 1 . .
. d. • d
by distilling mixture of potassium nitrate or so rum nitrate an co ncentrated sulphuric acid.

Example 2. Who prepared Nitric Acid first?

Ans. Glauber

Occurence
• In nature nitric aicd exist in both: combined state as well as free state.
• In free state, it is found in rain water, in traces after lighting.
• In combined state, it is found in the form of metallic nitrates such as chile saltpetre (NaN0 3), Nitre (KN03) or
Calciu m Nitrate [(Ca(N03)2l

Example 3. Define Nitrogen Fixation.

Ans. The conversion of free atmospheric nitrogen into useful nitrogenous compounds in the soil is know n as
Nitrogen Fixation.

Example 4. Why is Nitric Acid also known as Aqua Fortis?

Ans. Nitric acid is known as aqua fortis which means strong water. It is so called because it reacts with almost
all metals. It can even dissolve silver which does not dissolve in other acids.

Formation of Nitric Acid in atmosphere

Traces of nit ric acid come on t o t he earth in form of Acid rain.

N2 + 0 2 Lightning/ ➔ 2NO
Thunder
Nitric acid
2NO + 0 2 ~ 2No 2
Nitrogen dioxide
4N02 + 2H20 + 0 2 ~ 4HN0
3
(Nitric acid)
0
rrrr
 ,r,ple 5•
Name an acid formed b
. Y covalent and co-ordinate bon
d b t:h
°·
po (1) Nitric Acid (HN03)

,p• -rN•!
H
(2) sulphuric Acid (H 2S0 4)
0
t
H-0- S- 0-H
-l-
0

ITOPl~2 1
METHODS OF PREPARATION
Laboratory Method: In laboratory, Nitric acid is prepared by distilling either sodium nitrate or potassium
nitrate (NaN03 or KN03) with concentrated sulphuric Acid.
Below200°C
KN03 + H2S0 4 KHS04 + HN03
(cone)
Below200°C
2KN03 + H2S0 4
(cone)

5J fmportant
.. T/'; e reaction mixture temperature should not be exceed 200°C.
.. ~or.c HQ can't be used in place of Cone. H2S04-
.., The apparatus used must be made of glass.

&ample 6. Why pure nitirc acid is colourless but in laboratory it is slightly yellow in colour?
Ana. The yellow colour is due to dissolution of reddish brown coloured nitrogen dioxide gas in the acid. This
gas is produced due to the thermal decomposition of nitric acid.

Manufacture of Nitric Acid

nductriall, . N' .
~. 1tnc, Acid is formed by Ostwald's process.
Inu,·6
and~ Process_ catalystic oxidation of Ammonia is done. Then Nitrogen mono oxide formed is further oxidised
Yabsorbing water it converts int o nit irc acid
Pt
ooovc , 4NO + 6H 20

sovc
2NO + 02 - - 2N02

Nitric Acid I'J!., 1.a.~Q

 Inlet fo r 0 2
+Wa ter

□,n,□[
Catalytics
chambe r
ater gases
Platinum .....-- - - .
(catalyst) ~60
~~bb ,.,,..,.r -~ Outer stone
~~
(.)dbb ,~JOt- -+ Atogrp tion lower
{)00
t
Cooling pipes
'UV"'-'1- "l!!!r~ Diuta nitric acid

· .
Flow Chart of the Manufacture of Nitric ac1.d by OstWald's Process

1--r --__ ___ Oxygen from air

Ammonia (obtained by Haber's process) 7
Cataly tic charac ter chamb er

Oxidation chamb er
(The tempe rature is reduced so_ as t~
carry the reaction in forwar d diract1on

50°C
2NO + 02 2N02

Absorption Tower

Exam ple 7. Why the appart us used for manufacturing of Nitric

acid is made up of glass only?
Ans. It is because the vapour of Nitric Acid are corrosive, therefore,
it damag es the rubber and cork.
Exam ple 8. Why cone. HCL cannot be used in place of cone. HNO
3?
Ans. It is because HCl is volatile in nature. Hence HN03 vapour
will carry HCl vapours
Exa!m )~_!! Why the temperature of the reaction in laboratory
than 200°c process should not be exceed more

Ans. It is because sodium sulphate formed at higher temperature

forms a hard crust which sticks to t he walls
of the retort is difficu lt to remove, althrou gh the yield of HN0 is higher
3 .
7200°C
NaN03 + NaHS04

Example 10. At which concentration the nitric acid is known as

fuming nitric acid?
Ana. 98% concent rated acid is known as fuming Nitric Acid.

ITOPIC 3 I
PROPERTIES
Physical Properties
• It is a colourless liquid (98%) but commerical HN03 {68%) is
yellowish brown in colour.
• It had a suffocating smell.
• It is sour in taste. {Acidic)
• It is Hygroscopic (moisture absorbing) and forming fumes in
air.

1 1 _ _,...
•
r_rrrrr ~
..-.u ~ EduL art ICSE C
, r,,ical properties
C~e ·d is unstable and it decom of sunlight)
Nitric Ac 1 poses even at room temperat ure (in the presence
, A
4 HN03 ~ 2H20 + 4N0 + 0 2
2
of Indicators
EffeCt
Indicator Colour Chang•
Blue litmus Blue Red
Phenulpthalein Colourless Colourless
Methyl orange Orange Pink

oxidising Properties
·on on non-metals:
' Actl
Non-metal+ acid ~ Oxidised + water+ Nitrogen dioxide
(cone) product
C + 4HN03 ~ CO 2 + 2H 20 + 4N0 2
S + 6HN03 ~ H2S0 4 + 2H 20 + 6N02

1
Action on metals
(l) Cold and dilute HN03-
3 Cu + 8HNO ~ 3Cu(N0 3)2 + 4H 20 + 2NO
(2) Hot and Cone HN03-

Uses
It isused in manufacturing of dyes, paints, fertilizers and aqua regia.

Identification
, It give dense reddish brown fumes with copper.
, Brown Ring test

Example 11. Identity A, B and C in following ractions:

A B ~
(1) Na2C03 ~ NaN03 ~ 02

12) Mg ~ Mg(N0
3 h~ N02 ~ HN03

Ms. (1) A Na2C0 3 + 2HN0 3 ---► 2NaN03 + H20 + CO2

B: 2NaN03 ~ 2NaN0 2 + 02
(2) A Mg + 2HN0 3 ~ Mg(N03)2 + H2
(V. dil)

B: 2Mg(N0 3)2 ~ 2Mg0 + 4N02(9) + 02

reddish
brown gas
C: 4N02 + 2H 20 + 0 2 ~ 4HN0 3

Elarnpte 12. Why HN0 3 is not used to purify gold?

. ac1'd.
~,. It is be cause go ld contain impurities of Cu, Hg, Cu, Pb, etc. and t here can be d'1sso.lve d .1n N'1tnc

Oicse
-. s Suggestions
r::Yat,on
~bservation-based questions. While studying any chapter, stress upon related observations like colour changes,
ofp ..
" Und rec,p,tates, gases temperature, etc.
erstand h
" Pract· t e meaning of 'relevant observations.
ice Vvrf
1
Ing balanced chemical equations.
0

N1tr1c Cl
rrrr
. . A 'd /-tj 441
 ·t·ty of precipitates formed using reagents.
o/our I solub, , .
• Focus on the c . b rvation-based questions.
wenngo se
.,. Practice ans hort notes tables for facts and concepts.
fl diagrams, s '
.,. Prepare ow d definitions well with the correct terms/key words.
.,. Learn the Laws an

( OBJECTIVE Type Questi0 ns )

Explanation: ~one. nitric acid gives broWn
Multipie Choice Questio n [ 1 mark ] fumes on heating.
(Strictly for ICSE Semester II Exams) /J.
4HN0 3 ~ 2H20 + 4N0 2 + o2
1. The chemical used in brown ring test is Brown fumes
Nitrates (other than potassium, sodium
(a) CuS04
(c) Fe2(S04)3
(b) FeS04
(d) ZnS04
ammonia) produces reddish brown fumes
O d
:f
N02-
Ans. (b) FeSO 4 6. The laughing gas is ..............
Explanation: Brown ring test is used to identify
(a) Nitrous oxide
t he N0 3- ion in which freshly prepared solution
(b) Nitric oxide
ofFeS0 4 is used.
(c) Nitrogen mono oxide
2. Nitiric acid is a .............. acid. (d) None of these
(a) Strong (b) Weak Ans. (a) Nitrous oxide
(c) Neutral (d) None of these Explanation: Nitrous oxide is formed by
Ans. (a) Strong decompos ition of Ammonium nitrate.
Explanation: Nitric acid is a mineral acid. In ~
an aqueous solution HN.0 3 acid dissociates NH 4 N03 --? N20 + 2H20
completely into W and N0 3- ions, therefore it It is known as laughing gas due to its euphoric
is considered as a strong acid. effects of inhaling it.
3. The basicity of nitric acid is .............. 7. The brown ring test is used for detection of
(a) 3 {b) 4
(c) 2 (d) 1 (a) C03- 2
Ans. (d) 1 (c) S03-2
Explanation: The basicity of an acid is defined Ans. (b) N03-
as the number of H3o+ ions that can be
produced by the ionization of one moleuclar of
8. Aqua regia is a mixture of ..............
(a) dil. HCl and cone. HN0 3
that acid in aqueous soltuion. Nitric acid looses
one hydrogen ion and forms one H3o+ ion. So (b) Cone. HCL and dil. HN0 3
its basicity is one. (c) Cone. HCL (1 part) and cone. HNOs
(3 parts)
4. Rain water contains traces of ..............
(d) cone. HCl (3 parts) and cone. HN03
(a) HN03
(1 part)
(c) CH3COOH (d) None of these Ans. (d) Cone. HCl (3 parts) and cone. HNO_:
Ans. (a) HN0 3 (1 part)
Explanation: Rain water is a mixed electrolyte Explanation: 3 parts of cone. HCl and 1 part of
th at contains various amounts of major cone. HN03 gives a mixture called aqua reg ia
and minor ions such as sodium, potassium, (royal water)
magnesi um, calcium, chloride ions are major HN03 + 3HCl ~ NoCl + 2H 20 + 2[Cl)
con stituents one the ammonia, nitrate and
nitrite ions. Nitrosylchloride
This.mixture reacts with even gold and platinum
5. The gas which gives reddish brown fumes is to give their chlorides.

9. Nitric acid ism anu tiacture db

y ..............
(a) 02 (b) CO2
(c) N02 (a) Contact process (b) Ostwald's process
(d) Cl2
Ans. (c) N0 2 (c) Haber's process (d) None of these
Ans. (b) Ostwald's process

442 CJ/:, Educ'or t ICSE Chemis try Class X

 ~p
toriotion:
. oxid atio n of NH 3 into NO
(a) Poly nitro us tolu ene
(b) Citr ic acid
l
sceP 1. Pt
(c) Trln ltro tolu ene
NH 3 + 502 aoo c ) 4NO + 6H 2 o + Hea t
0

4 (d) Dlcu trou s tolu ene

2: oxid atio n ofH N03 in oxid atio n cha mb toul ene
sceP sooc er Ans. (c) Trin itro to luen e . .
2N0 2 Exp lana tion ·. Tnn1tro TNT or
2NO + 0 2 . 'd
ly kno wn as .
com mon
. Abs orpt ion of N02 in wat er is
ene . This is a yell ow ac'.
sceP 3· 2, 4, 6 - trini tro toul
4N0 2 + 2H2 0 + 02 ~ 4HN o 3
(aq)
as a reag ent in
whic h is occa sion ally used
ng of the bes t kno wn
., oxide is used in manufacturi che mica l synt hesi s. It is one of
Nitr•
i0, tosives such as - - - expl osiv e mat eria l
eJCP

( SU BJ EC TI VE Type Qu es tio ns )
Pt 4NO + 6H 2 0 + Hea t
[ 1 ma rk] 4NH 3 + 502 -a--'-oo..:..o-c-4
'II jr, The Bla nk• s
FI1, The valency of nitr ogen is .............. .......
17. Aqua regia is also known as .......
1
Ans. Three (3) Ans. Roy al wat er
N(l) == 2, 5 Explanation: A mixture of cone
. HN 03 and
explanation: Nitrogen have 5
electrons in al wat er
cone. HCL in ratio of 1: 3. It is called roy
complete
outermost shell. It nee d 3 electron to because of its ability to dissolve gold
.
its octet.
ed by ..............
.............. 18. Nitric acid is industrially pre par
12, In the free state, nitric acid is found in
Ans. Ost wal d dilu tion proc ess.
Rain wate r
t,.r,s.
0 is pres ent pre par ing
Explanation: In rain wat er HN 3 19. Am mon ium nitr ate is used in
es afte r
in free states. There it occurs in trac
Ughtning. Ans. Lau ghin g gas
..
13, The formula of chile salt pet re is ............ Explanation:
Ans. Sodium nitr ate (Na NOJ ) NH4N03 ~ N20(g )
talline laugh ing gas
Explanation: ft is a deli que sca nt crys
sodium salt which is fou nd chiefly
in noth ern explosively
Ammonium nitr ate dec omp ose s
Chile. leaving behind no residue.
..............
14. The nitric acid was form erly kno wn as 20. The mo lecu lar mas s of nitr ic
acid is ..............
Ans. Aqua Fortis
rly all Ans. 63
Explanation: Nitric acid reac ts with nea Exp lana tion :
a fortis
metals and was form erly call ed aqu
the sam e HN 03
because it looks like wat er and has
· 1) + (1 14) + (3 X 16)
viscocity as water. = (1 X X

15• The colour of nitric acid is yel low due to = 1 + 14 + 48

A Presence of .............. gas = 63

ills. N02 h copper
21 . Cold, dilute nitric acid reacts wit
es into n dioxide,
Explanation: Nitric acid dec om pos to form .............. (Hydrogen , nitroge
is a redd ish
Water, N02 and free oxy gen . N0 2 nitric oxide).
[ICSE 201 4]
brown g D is yell ow
in l as. ue to its pre sen ce HN 0 3 Ans. Nitric Oxide.
co our
16, Th 8 . Explanation:
i~
•, cataly st used in oxidation of am mo nia 3Cu + 8HN 0 3 ~ 2NO + 4H 20 +
3Cu(N0 3h
An ............
t· rn
s. Piainu
nitric oxide
-.-[Marking Sch~meJ \
Explanati . Ox1. dat1. on of amm oni a: ~' ,· ' '

on.
0

Nitric Acid ~ 44 3
 rrue / False [ 1'11ark
Match the Following • Nitric acid is a dibasic acid.
[ 1 mark ] 24
Ans. False . .
Explanation: It 1s a monobas1c acid.
Column (I) Column (II)
22. • Nit ric acid ls a strong oxidizing agent
(i) Nitric acid (a) N0 2 gas 25
(b) Nitric acid Ans. True
(ii) Liberation of Explanation: It vigorously oxides non-
hydrogen on
rneto11,
metals etc.
reaction with
26. Nitric acid is formed by Haber's process
metal
(iiQPure nitric acid (c) Aqua fortis Ans. False
Explanation: It is formed by Ostwald's pr0Cei:.
(iv) Brown ring test (d) Oxidizing agent 3

(e) Colourless Vanadium Pentaoxide is used as a COtah .

(v) Mixture of nitre 27• ~ m
Ostwald process.

Ans. (i)-(c), (iO-(a), (iiO-(e), (iv)-(b), (v)-(d), Ans. False

Explanation: Platinum is used as a catalyst ir
Explanation:
ostwald process.
(i) 3 part of HCl and 1 part of HNO3 froms
aqua fortis. 28. Nitric acid is used in manufacturing of
(iQ Cu + 4HNO 3 ~ Cu(NO3) + 2H2O + 2NO2 explosive.
Zn + 4HNO 3 ~ Zn(NO 3)2 + 2H2O + 2NO2 Ans. True.
Explanation: HN03 ~s used in the manufacturing
(iiQ Pure nitric acid is colourless liquid (98%
concentration) but the commercial HNO3 of explosives like T.N.T. (triniro toluene).
(68% concentration) is yellow ish brown in
colour. Give Reasons [ 1mark J
(rv) FeSO4 + 3H 2SO 4 + 2HNO 3 ~ 3Fe2(SO4)3
29. In laboratory preparation of nitric acid why
+ 4H2O + 2NO
cone. HCl can't be used?
FeSO4 + NO~ FeSO4.NO
Ans. Cone. HCl can't be used in laboratory proparatior
(Nitroso ferrous sulphate, a brown compound)
of nitric acid because HCl is volatile and henee
(v) A mixture of nitric acid with sulphuric acid
forms a mitrating acid. It acts as a strong nitric acid vapours will carry HCl vapours.
acid. It neutralizes all boxes. It is on strong
30. Why is the glass appratus only · used in
oxidising agent and mitrating agent.
preparation of HN0 3?
23. Ans. Only glass apparatus is used in the preparation
of HNO3 because nitric acid vapours react with
(i) Nitre (a) NaN0 3
rubber and cork.
(ii) Chile saltpetre (b) N20
(iii) Nitrosyl chloride (c) KN0 3 31• In laboratory preparation of HN0 3 why the
(iv) Laughing gas (d) Cu(N0 3)i temperature should not be exceed than
200°C?
(v) Co~per nitrate (e) NOCL
Ans. In laboratory preparation of HN0 3 the
Ans. (ij-(c), (iij-(a), (iiij-(e), (iv) -(b), (v)-(d).
Explanation: temperature should not exceed 200° C because
Na2SO4 formed at higher· temperature forms 0
(i) Nitre is t he universal form of KNo 3. It is also
known as saltpeter or salt pertre. ha rd crust which sticks to the walls of retort
and is difficult to remove.
(ii) Na~O3 sodiu~ nit rate is a crystalline
sodium salt. It 1s also called chlle salt petre. 32 • Why higher ratio of air is used in
(iii) Nit rosyl chlorid e NoCl. manufacturing of nitric acid?
It is a yellow gas which is fo rmed as a Ans. H_ig~er ratio of air is used in manufacturing of
component of aqua regia mixt ure.
nitnc acid because oxygen is only 1/Sth in air
(iv) Laughing gas N2O is a colourless, non-
a nd it is required in all three chambers.
f~ammable gas at room temperature. It has
rightly metallic sceut and taste.
3 3. Why is the nitric acid stored in coloLJre d
bottles?
0
 . ·c acid is storedl.in coloured b0 tt les becaus or dark brown
N1trI Reddish brown or b_ro~n ed or evolve d
A~5• . resence of sun 1ght nitric acid decomposes
e
r ,,., p .h . . gas I fumes / vapou r is lroerat 'sh solution
t
wh1c. gives yellow colour o acid.
to N0 2 or released / blue solutio n I blUJ . ti med
1
rown ring
111 •
test why
•
y a freshl
prepared formod / a gas with punge nt smell JS :or
,,,. ,:eso
" 4 solution 1s used? which turns potass ium iodide paper broW~•
(for colour of gas - look fo r reddis h brown or
. Freshly _prepared FeS04 solution is used in
brown word) .
A~s brown nng test because on exposure t o the
to Fe 2(so 4)3 wh"1ch Note: (a) only word 'blue' not accepted. The
at," . es
...,, 0 sphere FeS04 oxidis
word 'Solution' fs a must No other col.our
will not give brown nng test. accepted. ·
(b) A gas with pungent ·smel:L should be
,s, WhY nitric acid i~ used to purify gold? followed with a confirmatory test Scheme),
Gold may contmn Cu, Ag, Zn, Pb etc as ·
.,,
· . : · , ; , . :[Mafking
/,, , /,. , / ,
5
A" ' irripurites which dissolve in HN0 3. ' '

wJ What Examiners say

, , WhY is nitric acid used to etch design on ._. The word gas was missing in many answers.
6 copper and brassware?
Nitric acid is used to etch design on copper and
& Cautionstudying, stress upon related observations
._. While
A"S,
brassware because HN03 acts as a solvent for like colour changes, formation of precipitates, gases
temperature, etc.
large numbers of metals except noble metals.
39. Concentrated nitric acid is reacted with
7, concentrated nitric acid appears yellow, sulphur. [ICSE 2019]
3
when it is left for a while in a glass bottle. is
Ans. Fumes of reddish brown nitrogen dioxide gas
[ICSE 2020]
released.
Ans. Concentrated nitric acid appears yellow, when · Chemical Equation:
it is left for a while in a glass bottle because S + 6HN03 (Cone.) ~ H2S0 4 + 6N02 + 2H20
concentrated nitric acid itself decomposes to ~/ ( ?' ,,

'-3/~ or ,brown gos of nitrogen

form reddish brown nitrogen dioxide gas which R'i ea: .
remains dissolved and imparts yellow colour to *:-; -,'· [Marking Scheme]
the acid.
.

Concentrated nitr,ic J fcicf .

,"'C'~- ... , ''f;,'(j,t";'''

WJ What Exami~e~: say

to form reddi;h' broW' ' 0
._. Many candidates either wrote the equation or named
"
the product formed instead ofstating the observation.
'

dioxide ga( / wl·Wc!i J:e ,

7 '# , ,.,,_/,· ,. ·-'•·>:~Y, ,c,4,. . , ·-:,;

(impar ts; ~~yello\,v wcolour-to~

" . !!-~· . ,,r.r;&W,,.$'<,>
40. Lead nitrate is heated strongly in a test tube.
,
[ICSE 2019]
formed ;dissotves~in, . "''ti ·•
C9lour-~·" · · · Ans. It forms a yellow coloured lead oxide and
.',
·;·, liberates nitrogen dioxide gas with reddis h
, f,: ',
brown fumes and crackling sound.
~ Wha~ Examin:rs say Chemical Equation:
.,. Many candidates did not mention the word 'dissolves' 2Pb( N03) 2~ 2Pb0 + 4N02 + 0 2
or dissolution of the gas. Instead, they simply wrote, -~ ~- ,,, ~ ,, '\\ "" ' "' "\.3:.2:,~.::~ .
duetoNO2. A 9~cre&it~~in9; sf ·
t '~
· ·- ~~rd i A-~~!'·
brown gos
il 'grven , , ,~tlQw ~~ ·"~,
left bEl,I{ In d ,.,,t · '. •'.,'( "":; ""·~ \-_~,- ::,l.1 ~;:, _', \;"'· '"', • ~*•

Write down the observation .' ~ \ [~rking ' '

', '\ ':._,

[ 1 ma rk ]
38, Acti
on of concentrated nitric acid on copper.
Jv] What Examiners say
wrote yellow precipitate of PbO is
I.+ Some candidates
[ICSE 2020) obtained instead of yellow residue.
Ans. Redd" h
is brown fumes are released and blue Dilute Hydro chloric acid is added t o Lead
solutio n ·is &.1ormed with a gas having punge nt 41.
nitrat e solution and the mixture is heated.
srnetl wh"ich turns potassium iodide paper [ICSE 2016]
6rown.
Chern·ical Equation: Ans. White precipitate is formed which dissolves
an heating.
Cu(s) + 4HN0 3~ Cu(N0 3)2 + 2H 20 + 2N02
_o_ __
 Ch em ica l Equation:
45 . Cu + dil. HN03 ~
Pb(N0 )2 + 2HC l ~ 2H Ans. 3C u + 8HN03 ~ 3C
llC:SE l
3 N0 3 + PbC l2 t u(N03h + 2No + 41,0tsl
whi te ppt.
3Cu + 8HN0 2 ~ 3Cu (N03h 20
A wh ite precipitat e soluble on + 2No
heating .
+4N2a
{M arking Scheme] [Marking Sch
el'\'\e}
~ What Examine rs say ~ What Examiners say
.,. Inst ead of stat ing the -. Many candidate s wrote N0
observation, can did ate s NO. 2 as a product in
eith er wrote the equ atio n stead Of
or nam ed the product.
Some candid ate s gave an
form ation of reddish brown
incorrec t observation of & Caution
gas. -+ Give ade qua te practice
in writing of bot
42 . When crystals of copper
nitrate are heated
chemical equatio · ns wit· h
necessary conditions. 0nced
in a test tube. -+ Use of structural formula
e for organic compou d .
{ICSE 2015] help stu den ts to wn.te equatio .
Ans. Wh en cry sta ls of cop
per nit rat e is hea ted it ns correctly. n sw,u
fi rst loo ses the wa ter mo 46 . Action of cold an d dil ute
lecule, on fur the r . Nitric
acid
hea tin g it dec om pos es to Co ppe r. on
give reddish brown
gas (N02) and oxygen. [ICSE 2017]
The greenish blue Ans. 3Cu + 8H N0 3~ 3C
cry sta l of Copper nit rat e wil u(N03)i + 4H 20 + 2No
l cha nge to black
colour Copper oxide.Chem
Equation:
ical :i99::+1~~,~~3~ 3S~(N03h + 4H 2o +2No
.,.,.~/ ,/ :i_ ._; -,~
:-,,. j .,
, :• r
, • •',J

,:,:~". ' ;; ,,
2Cu(N0 3h ~ 2Cu0 + 4N , .
, 4
;
-:- f .. {Marking Schernel
0 2 + 02
(Black) (Reddish brown) w-1 What Examiners say_
Reddish bro ~n-:i~:a~: ~t :.pit -+ Equation was written
gas is evohied·o n~ ~~tmc~r ~:~t
ht>~~~ ~aji~ra~~ with concentrated HNQ.
instead of dilute HN03. N02
was given as a produ~
aue.: ~f'~ ~Q; i~~ instead of NO. Balancing was
formed. · -~•:·~}}·/ ~~~~?-:·:\~{~it~~
·. ·. ·, ., ., ,.,[Mai 1n · cne •e}'
and som e made errors in wri
copper nitrate.
incorrect in many cases
ting the formula of
~,\ "\' t' ~\~.- .t:~7~1t.}_
;,~~ ~;\}tt..\¥'tt: }-~~~
ik7J What Examiners say 47 . Action of cone. Nitric acid
on Sulphur.
.,. Some candidates referred
to blue residue instead of l!CSE 20171
black or a red gas instead of Ans. S + 6HN0 3 ~ H S0
reddish brown or black 2 4 + 2H20 + 6N0 2
precipitate ins tea d of black (cone)
residue or nam ed the
product formed without rele
vant observation. !f._nt~ ,,r~#~ -,f•l')l'~ . ~v~-•
,.:":,t 'J, ';; ~lfft[icr :~
' ":'\

. H SO + 6NO + 2H 0
Give the balanced Chemica ·,5,;: ·,,,:.3 . · 2 4 2
l Equation t\ , · · :> · [Marking Schemel
2

[ 1 ma rk ]
43 . Reaction of car bon po wd er
nitric acid.
and con cen tra ted g;J What Examiners say
[ICSE 2020] -+ Some candidates com
Ans. C + 4HN03 mit ted common mista~es
~ CO2 + 2H20 + 4N02 bywriting SO 2 as a product.
C + 41-IN03 ~ CO2 ::j. 2Pi20 -f 4NO:~ & Caution
[Marking Scheme} -+ Understand that norma
lly Nitroge n is chemically 1
unreactive but it rea cts whe
WJ What Examiners say n cata
and a tem per atu re of 700 - 800 lyst such as Pt
°c is used and gets
•
..
-. Some can didates did oxidized to NO. •·.-
not balance the equations
wrrectly. Som e wrote CO ins
instead of N0 2.
tead of CO2, or NO 48 . Laboratory preparation of
Nitric acid
'•
. ~"
44 . S + cone. HN 0 (ICSE 2017]
3 --? [ICSE 2019]
Ans. S + 6HN0 3 - - ? H S0 Ans. NaN0 3 + H S0 below 200 °c
4 + 6N0 2 + 2H20 i:
2 2 4- - --~ NaHS04+HN0 3
S + 6HN03 --+ H2S 04 +
6N02 + 2H20 NaN0 3+ H2S0 -· -·
4 ➔ ;200;CNdHS04 ;:HN03
[Marking Scheme} . .'\ l~~r~i~g Scheme]
g;J What Examiners say ~·
rv Wh at Ex
I\,

.,. A large number of can

didates ma de errors in
aminers say 1
h,
-+ M t '
balancing of the equation and os can d',dates answered this.
/or writing the products. correcttY· sorri
d ef
Many candidate s wro te SO candidates recorded the pro
ductsas NaS04 in 5rea 0
2 as a product instead of NaHSO+
H2SO4
0
Tr'l "
 49• "'oeaction of Ammonia with N"itr1c. acid. Chemical Equation:
NH 3 + HN03 ~ NH 4 No 3 .
[ICSE 2017] 2Zn (N0 3) 2 ~ 2Zn0 + 4N02 + 0 2
ArtS· Yellow (cuhen hot)
NH 3 + HN03 ---► NH4N0 3
57 • Dilute nitric acid and copper carbonate.
[Marking Schema] [ICSE 2012]

w,J What Examiners say Ans. CuC0 3 + 2HN0 3 ~ Cu(N0 3)2 + H20 + CO2

,.. M
ost of the candidates answered correct/ A fe
d · h h fo
58. Preparation of ethane from sodium
contuse wit t e rmu la of ammonia asy.NH4. w "lnot propionate. [ICSE 2014]
;O, Action of hot and concentrated Nitric acid Ans. Cu + 4HN0 3 ~ Cu(N0 3) 2 + 2H 20 + 2N02
on copper. [ICSE 2016] (cone.)
A11s. Cu + 4H N03 ~ Cu(N03h + 2H20 + 2N02
KN03 + H2SO~(conp) ~ KHS04 + HN03
Cu+ 4HN03~-~u(N03)~ + 2H 2Q'+; 2NO or with NaN03
~ . ·· .-. ·, ·JM_~-~lci~g Scheme] , ,
[Marking Scheme]

~ What Examiners say ~ What Examiners say

,.. some candidates misrepresented the reactant -. Candidates referred to the reaction at temperatures
Na2CO3 instead of Na~CO3 while some others wro~= higher than 200°C and hence lost marks
the product as H2CO3 instead ofH2O + co 2, an often
repeated error. Name the following [ 1 mark ]
51. Laboratory preparation of nitric acid. 59. The compound responsible for the brown ring
[ICSE 2014) during the brown ring test of nitrate ion.
<200°C Ans. Nitroso Iron (II) sulphate or Nitroso ferrous
Ans- NaN03 + H2S04 - - ~ NaHS04 + HN03
sulphate
Nitric Acid
Explanation: The brown ring of nitroso ferrous
52, Sulphur is treated with concentrated nitric sulphate decomposes on disturbing the test
acid. [ICSE 2013) tube. The • heat envolved decomposes the

Ans. Nitrigon dixoide (N0 2) unstable brown ring.

Chemical Equation: 60. Name two gases one of which is basic and
which combine to give a solid.
S + 6HN03~ H2S04 + 2H20 + 6N02 i
Ans. Ammonia and Hydrogen chloride
Sl. Afew crystals of KNO 3 are heated in a hard Explanation:
glass test tube. [ICSE 2013) NH3 + HCL ~ NH 4 Q
hrs. Oxygen (Oi) (basic in nature) (Ammonium chloride
Chemical Equation: white solid)

2KN 03 ~ 2 KN0 2 + 02 i 61. Name a solution which gives nitrogen dioxide

with copper.
S4. Oxidation of carbon with concentrated nitric
Ans. Cone. HN03
acid. [ICSE 2013)
Explanation:
fill$. C + 4HN03 ~ CO 2 + 2H20 + 4N02
Cu + 4HN03 ~ Cu(N0:3) 2 + 2H 20 + 2NO?
SS, The gas produced when copper reacts with cone.
concentrated nitric acid. [ICSE 2012)
Ans. Nitrogen dioxide gas 62. A nitrate which leaves behind no residue on
heating.
Chemical Equation:
Ans. Ammonium nitrate
Cu + 4HN0 3 ~ Cu(N0 3)i + 2N02 + 2H20
Explanation:
S6, Zin ·
c nitrate cryst.als are strongly heated. NH4N03 ~ N20 + H20
A. [ICSE 2012]
63. Name the test carried out with freshly
ns. Zinc Nitrate Crystals on slowly heating produces
redd ' prepared ferrous sulphate.
~l1 ish brown gas (NO v, -' a colourless gas t hat
Ans. Brown ring test.
ndles the candle flame. In the test tube a
Explanation: A freshly prepared ferrous
Yellow ppt is left which becomes white on
cooling. sulphate solution is used, because on exposure

JfJ.!_ I. I . Pf
 Ans. Nitric oxide
. . d to form sulphate Explanation:
to the atmosphere, it is oxidise .
which will not give the brown ring. 3CU + 8HN03 - - t 3Cu(N03)2J., + 4H20 + 2No
copper reacts cold and oil t
64. Name the gas produced when
with cone. HN03. • Name the common name of carban,ide.
73
Ans. N02 Ans. Urea
Explanation: t Explanation: Urea is also known as carb .
Cu + 4N0 3 ~ Cu(N0 3)2 + 2H20 + 2N0 2 · an organic compound with chemical fioornide,
,s rrnul
cone. NH coNH 2. It has two - NH2 groups joined ba
2
a carbonyl functional group. Y
65. Name the property of nitric acid which allow
it to react with copper.
74• The acid which
.
is used in the preparati
. on of
Ans. Q)'{idizing agent a non-volatile acid. [ICSE 2015
66. Name a fertilizer prepared with the help of Ans. Concentrated Nitric Acid (HN0 3) l
nitric acid. Concentrated nitric acid
Ans. Calcium nitrate [Ca(N03)i]
[Marking Scheme]
Ammonium nitrate NH4N03
67. Give any one industrial use of nitric acid. ,VJ What Examiners say
Ans. (1) In formation of explosive TNT. -+ candidates failed to mention the concentration ofth
acid even if the right acid was identified and hen~
(2) In making synthetic fibres like artificial silk,
lost mark.
nylon, celluloid, plastics etc.
68. Name the substance due to which nitric acid 75. The acid which is prepared by catalytic
become yellow in colour. oxidation of ammonia. [ICSE 2015]
Ans. N02 gas Ans. Nitric Acid
Yellow colour of HN03 is due to dissolution of 76. The dilute acid which is an oxidizing agent
reddish brown coloured N0 2 gas in the acid. This [ICSE 2019)
gas is produced due to thermal decomposition Ans. Nitric acid
ofHN03. ,. .

4HN03 ~ 2H20 + 4N02 + 02 ,. 1 HND 3 0r nitric acid ·

~>//''://' < .)
69. Name a colourless gas which becomes [Marking Scheme]
reddish brown when it comes in contact with
atmosphere. W-J What Examiners say
Ans. Nitrogen dioxide -+ Many candidates listed HCl or H2S0 4 as an oxidising
agent instead of nitric acid.
70. Name a catalyst used in manufacture of
nitric acid by Ostwald's process
& Caution
-+ Understand the fact that only nitric acid in dilute and
Ans. Platinum concentrated form can act as an oxidizing agent
Explanation: In Ostwald's process, Pt is used as
catalyst at 800°C for oxidation of NH 3 gas into 77• The gas produced when sulphur is oxidized
nitric acid. by concentrated nitric acid. [ICSE 2018]
Pt Ans. Nitrogen dioxide (N0'.2)
4NH3 + 502 aoooc ) 4NO + 6H 20 + Heat
, Nitrogen dioxide or NO~,
71. Name the salt used in laboratory to prepare
nitric acid. [Marking Scheme]
Ans. Sodium or Potassium nitrate 01
>'✓- What Examiners say
Explanation: -+ ln stea~ of N02 some candidates wrote SO ?, H:zS or
< 200°C N2 while some others wrote N02 and S02. -
NaHS0 4 + HNo 3
cone. 78• Action of cold and dilute nitric acid on copper.
< 200°C [ICSE 2018]
KHS04 + HN0 3
Ans. Nitrogen monoxide (NO)
cone.
Nitric oxide/ n.itrogen monoxide or NO
72. Name the gas produced by the reaction of dil
HN0 3 on copper. [Marking.Scheme]
0

448 Educ;'art ICSE Chemistr Cla s x

 sti0 5
Short Answer.. f rype Qu •
"
~ What Examiners say
idates were able to give , correct [ 2 mn rk J
fl ,Atl7i/e most cand
i.t vv, fe
e the gas correct/ . fl8 oWre of the
answer. b~t a w ~oul~ not nam nitri spe cial LoboratOt!I
/led it nitrogen OX/dNe instead of c ox'd y
I e or gave 91. (A) What ls t he 11 8
ca
the incorrect answ er 0 2. app ara tus tha t ls used in t
. rep· oration of nitric acid?
P of the
w11at happens when [ 1 ma rk J ature not be
(8) Why should the temp~r
Nitric oxide is oxidised reaction mixture of Nitric acid
19• Nitric oxide is oxidised to nitrogen dioxide allowed to rise above 200°C?
mad e of all glass.
/iJJS,
2NO + 02 ~ 2NO 2 Ans. (A) The apparatus mu st be
decomposes at higher
con e. H2so4 (8) Nitric acid
SO, potassium nitrate is treated with tem per atur e and the sod
ium sulp hat e
above 200°c app ara tus _and
form ed sticks to the glass
Nitr ic acid is formed. can't be removed.
Ans. < 200°c
KNO 3 + H2SO 4 + HNO3
KHSO4 realating
(cone.) 92. Copy and complete the table Output
ortant industrial processes.
to imp
ition of cess not the
Si. What result we get by decompos refers to the product of the pro
Nitric acid? intermediate steps. -
lly decomposed, it
Ans. When nitric acid is the rma (A)
gives nitrogen dioxide gas. . / Narfie\of.pfocess
NH3 + air
LiHNO3 ~ 2H2O + 4NO2 + 2
0 Inputs
bisu lphate (8)
82, Sodium nitrate react with sodium Catalyst
above 200°C. Chemical equation
(C)
ium sulphate along
Ans. It results in form atio n of sod HNO3
out put
with nitric acid.
I

presence of
83, Ammonia reacts with oxygen in Ans. (A) Ostwald's process
platinum at 700 - 800°C. (B) Platinum
ic oxide gas. Pt
Ans. It results in form atio n of nitr (C) 4NH3 + 502 800°C
Pb
3 + 502 - - -oc-_- - 0-c__. 4NO
+ 6H2O
4NH 700 800 apparatus
93. (A) Explain why only all glass ation of
3? should be used for the prepar
84. When carbon react with cone. HNO ed H2SO4
CO2 gas HNO3 by heating concentrat
Ans. N0 2 gas produced along with
+ 4NO2 and KNO3•
C + 4HNO3 ~ CO2 + 2H2O n to illustrate the
(8) Write a chemical reactio
.85, Copper rea ct with diL and cold
HN 03 acidic nature of nitric acid.
ogen mon o oxide acid are high ly
Ms. It results in formation of Nitr Ans. (A) The vapours of nitric s or
it destroy
gas. corrosive in nature therefore,
+ 4H2O + 2NO damage the rubb er cork
3Cu + 8HNO 3 ~ 3Cu(NO 3) 2 + H2 O
(8) NaOH + HNO3 --y NaNO3
86. Copper reac t with hot and cone. HN03 considered
O + 2NO2 94. (A) Dilute nitric acid is generally ction with
11.ns. Cu + 4HN O3 ~ Cu(N0 3)i + 2H2 a typical acid exc ept for its rea
17. Nitric acid rea cts with cone. HCl different
metals. In what way is dil HNO3
Aqua regi a gets formed. s whe n it rea cts with
Ans. from other acid
O + 2[ClJ
HNO3 + 3HC l~ NOCl + 2H 2 metals?
that
8&. Nitric acid is treat.ed with methyl
ora nge. (8) Acc ount for the yellow colour
ic acid whe n
Ans. Methyl orange con verts to pink in colo ur appears Is concentrated nitr
inary gla ss
nolphth alein. It In left standing in an ord
:• Nitric acid Is treat.ed with phe bottle.
urless.
s. Phenolphthalein remains colo age nt therefore, it
Ans. (A) Oil HNO 3 Is an oxidizing es of
~ • Ammonium nitrat.e ia heat.ed. reacts with me tals to prod
uce oxid
s place leaving
ris. An ~xplosive decomposition take nitrogen and not hydroge n.
beh,ng no residue. ears yell ow
(8) Concentrated HNO3 app
olved NO 2
because of the presence of diss
NH4NO 3 ~ N2O + H2O
0

. Ac,.d
. r1c Jfl11
t::11 .! 449
N1t
 i
95. During storm (thun~er) rain water ~ontains Explanation:
nitric acid. Describe the reactions Pb(N0 3)2 + 2HC l~ PbCl2,J, + 2HNo
of
formation of HN03. (white ppt.) 3

Ans. N2 + 0 2 ~ 2NO (Insoluble in cold water but dissolve .

s 1n
2NO + 02 ~ 2N0 2 water) Vvorrn
4N0 2 + 2H 20 + 0 2 ~ 4HN0 3 Pb(N03)2 + H2S04 ~ PbS0 + HN
4 2
03
96. Identify A, B and C in following converslble. (White PPt
A On adding lead nitrate solution 'f .)
B
(A) Na2C03 ~ NaN0 3 ---) 02 precipitate is formed which ' Id. Wh'1te
.
on heating, t hen 1t . . d"l
A B C 1s I ute HCL Ifissolve
w . 11
(B) Mg ~ Mg(N 03h ---) N02 ~ precipitate formed does not dissol hite
heating, it is dilute H2S0 . Ve on
4
HN03
Ans. (A) a: Na2C03 + 2HN0 3 ~ 2NaN0 + H 0 [Marking Scherne)
3 2
+ CO 2 ~ What Examiners say
b: 2NaN03 ~ 2NaN0 2 + 0 2 ,.,. White precipitate was mentioned by
(8) a: Mg + 2HN0 3 ~ Mg(N0 h + H candidates but the effect of heat on both :evera!
3 2 mentioned. as not
(Vdil)

100. (A) What is the type of salt formed When

b: 2Mg(N 03h ~ 2Mg0 + 4N0 2 + 0 2
the reactants are heated at a suitable
c: 4N02 + 2H20 ~ 4HN0 3 temperature for the preparation of nitric
acid?
97 • Write balanced equations for following:
(8) State why for the preparation of nitric
(A) Nitric oxide comes in contact with
atmosphere. acid, the complete apparatus is made up
of glass. [ICSE 2018]
(8) Nitric reacts with cone. sulphuric acid.
Ans. (A) Acid Salt
Ans. (A) 2NO + 02 ~ 2N02
(8) All glass apparatus is used for preparation
(B) KN03 + H2S04 below2oooc KHS04
(cone.) of nitric acid because Nitric Acid vapours
are highly corrosive and they attack Rubber
+ HN0 3 and Cork.
98. (A) Why the gases entering in catalystic f/~t ,t ✓,,. t: .,_,'

chamber during Ostwald's process must

l:>t~!./fc_itl-~; ',Salt/
,-::..,;: _,:: ,

· bi_sulphate/ hydrogen
?('f·~:/'} •,Y,lp~atef:'NaHS0 4/ KHS0 4
be pure? ;:'.t,W [ ,( l:t\e!'vcipour of nitric acid being highly
,1¼,_;'.; ,\._ ~f ,~,(
,f, <• ;1, .; I
(8) Why the gases are sufficiently cooled '?'.:/,,)'.,,\:, f:oryosi;ve/ HN0 3 vapours attack
before gases enters the oxidation i~,t~,J : Y:~bbe_r, cork etc./ HN0 3 vapours do not
chamber? 't\.~' J 1.,,rea'ct.zwith glass.
r,~\.--.\_/-~} , \
Ans. (A) Gases entering the catalytic chamber ~.·. · [Marking Scheme]
must be pure, otherwise, it would poison
the catalyst. w-1 ~h~t Exam;ners say
(B) To do the complete oxidation of nitric oxide ,.,. (A) Instead of acid salt, some candidates wrote
takes place as the rate of forward reaction normal salt.
,.,. (B) Most candidates answered correctly but a few
increases or to minimize decomposition of
stated that rubber will melt due to heat or cork
Nitrogen dioxide. will break.
99. Distinguish between dilute hydrochloric acid & Caution
and dilute sulphuric acid. (using lead nitrate ,.,. Understand thoroughly the preparation of nitric acid,
solution) [ICSE 2019] equations with conditions, setting up of apparaws.
precautions, material suitable for its storage, etc.
Ans. Lead Nitrate solution reacts with dilute
hydrochloric acid to give white precipitate 101. How will you distinguish between dilu~e
of lead chloride which dissolves on heating hydrochloric acid and dilute sulphuric acid
whereas on reacting dilute sulphuric acid with using lead nitrate solution? [ICSE 2oi 7l
lead nitrate solution an isoluble precipitate of Ans. On adding lead nitrate solution to dilu~e
lead sulphate is formed which does not dissolve hydrochloric acid a white precipitate 15
further. formed which is soluble in hot water.

l:i!J
0

450 Educ:'art ICSE Chem istry Class X

 . used in t he
aratu s ,s "d
o pp f nitric ac1 ·
ding _Lead n it_ rate solut ion to dilut e (C) An all glass ° [!CSE 2 0 15]
on ad Labor atory prep arati on
l huric acid a whit e preci pitate is forme d
SU~ h is solub le in hot w ater. trong oxid ising
vvh1c t ri c aci d ha o ver y n hydr og en
adding lead nitrat e. solut ion to b ath ' Ans. (A) D ilu te ni
0 n form w h'tI prec1. p1tate nat ure and it does not relea se d Mn.
but t he one )
,,
t he~ h' . . ga s w it h all m eta ls exce pt M g an 3
in which_ WH C 1tle phr: lc1p!tate disap pears on n it ri c aci d d~
( d
N'? e
ati'r19 is ' .w ,I e in H 2S0 4 t he wh 1'te (B) Con ce ntrat ed G ·tro gen · 1ox1, h
he d ecom poses t o ,orm nl
precipitate re_m arns insolu ble on heat ing. (N0 ) whi ch is a reddi sh brow n gas whic
2 O y ellow
[Marking Scheme] disso lves in it and h en ce gives
colou r.
~ What exam iners say attac ks rubb er, wood , meto L
corre ti (C) As nitric acid 3
So an all glass appa ratus is used a s HN0
'l,t' candid ates failed to
.,. M_a~Yguishbe tween dilute HCl and dilute H y
2so 4c as
distm f h- . . is very corro sive in natur e.
1tatde forme
_ d with HCl
thesolubility o w it~ pl rdec1dp
/?eating was not '.nc u e an instea d, forma
tion (A) Dilute nitric acid a,Lso has oxidi,z ing
011
{ brown N0 2 gas with H2S0 4 was menti oned which
prope rties does not form H2 with a ll
: as not possible. meta ls exce pt Mg & Mn / p rodu ces
oxide s of nitrog en
Lead nitrate crystals are heate d in a hard
2
10 • glass test tube. (B)_ Cone. HNO 3 deco mpos es t o form
[ICSE 2013 ]
nitrog en dioxid e whic h disso lves in it.
n
oecripitation takes place , A reddi sh brow Or
f,J1S- gas is forme d and a yello w resid ue
is left in Cone. HNO 3 produ ces redd ish b rown
the test tube. gas which disso lves in it.
(C) HN0 3 vapo urs are ver y cor rosive in
i03, Magnesium reacts with nitric acid to the · natur e_ J they react w ith rubb er o r
Uberate hydrogen gas. [ICSE 2012 ] · . cork / they attac k o r dam age o r
to ) ::b~~~ de ·or destr oy any othe r mate rial
AnS- Magnesium react s with dilut e nitric acid ..,,• • , > ,,

Liberate hydro gen gas. [Marking Schem e}

104. Iron is rendered passive with fuming nitric
add. [ICSE 2012 ) gll Wha t Exa ~i~ers ~ay
g t he
ing _,. Candidates faced difficu lty i n e xp lainin
/iJls. Concentrate d Nitric Acid being a stron g oxidis
s reason.
agent oxidises Iron form ing a layer that make to m entio n the
_,. Some candi dates failed
being respo nsib le
Iron non react ive or passi ve. dissolution of NO 2 in the acid
or the yellow colou r of acid
105. Explain the following: _,. Majo rity of candi dates answ ered corre ctly.
(A) Dilute nitric acid is gene rally considered
a typical acid but not so in its reac tion ,Lh Caution chem ical
with metals. _,. Besides Learn ing to write balan ced
on t he role p layed
equations, stude nts need to focus
(8) Concentrated nitric acid appe ars yello
w react ions
by the acid in differ ent
when it is left stan ding in a glass bottl e.

,. Arin Jf~ .l..f:;1

 SULPHURIC ACID

Sulphuric acid is also called 'King of

chemicals'. It is commonly called as
"Oil of vitriol'
The compound 'sulphuric Acid' is form
ed up by covalent bonding and co-o
of H2SO4 is 98. rdinate bo nd · The molecular ....,
"10Ss

Example 1. Why is sulphuric acid

called· 'King of Chemicals'?
Ans. Sulphuric acid is called 'king of chem
icals' because there is no other man
used by such a large number of indu ufactured compound Which is
stries.
Molecular Formula = H SO
2 4
Molecular Mass = (2 x 1) + (1 x 32) +
(4 x 16)
= 98
Example 2. Calculate the molecular
mass of sulphuric acid.
Ans. H2SO4: (2 x 1) + (4 x 16) + (1 x 32)
= 98
Structure
0
t
H- O- S-O -H
t
0
H(l) = 1
0(8) = 2, 6
S(16) = 2, 8, 6
Occurence
It is a mineral acid which exist in free
as well as in combined state.
In free state, it is found in certain min
eral springs while in combined state,
(BaSO 4) etc. as Gypsum (CaSO 4.2H O), Barytes
2
Methods of Preparation
• By distillation of green vitriol, sulphuri
c acid is formed.
fl.
2FeSO 4.7H2O ~ Fe2O3 + SO2 + 13H2O + H so
(green vitriol) 2 4
• Sulphuric acid is industrially prepared
by 'Contact Chamber Process'. In this proc
ess it, follows following steps.
(1) Catalytic oxidation of sulphur diox
ide: It is done in catalytic chamber loos
pentoxide. The SO 2 is first prepared by ely packed with vanadium
Oxidation of sulphur or iron pyrite
S+ O2 ~S O2
Or
4FeS2 + 1102 ~ 2Fe2O3 + 8SO
2
(Iron pyrite)
Now in presence of Vanadium Pentaoxi
de (V2Os) at 450°C sulphur dioxide conv
erts to sulphur trioxide.
2SO2 + 02 V205400
/Pt
cc > 2SO3
(2) Absorbtion of S0 3: Sulphur trioxide
formed is absorbed in cone. sulphuric
acid (oleum: H2S2O7) acid to form Pyrosulphuric
SO3 + H2SO4 ~ H2S2O7
(cone.) (oleum or Pyrosulphuric acid)

45 2 CG, Educ;'ort ICS E Ch em istr y Class X

 . . .
") p;tution of Oleurn: Ole um is diluted b . sul phu ric
(;, . . cone.
Y odding co lculo ted om oun t of wa ter to obt ain
acid.
H2S 207 + H 20
-> - 2H2S0 4

u d cone. sulphuri c acid

... ale 3...! Na me the .cat aly st se for the O • • e.
~a, ..,:---· . ><idat1on of sulphur dioxid

I
; .. van od1 um Pen ta oxi de (V 2o 5
)

IToi 102 f
PROPERTIES
physical Properties
.
concentrated sulphuric aci d is col our les s d ourless, viscous h . . . . . wa ter in aU
. . d" . , o
t f . ygroscop1 c el,qu,d which 1s soluble in
ng 1bas1c acid . The sal ·d .
oport1ons. It 1s a stro o sulphuric oci are called sul pha te and bisulphates
pr •
ci,emical Popert1es
acid:
(N properties of dilute sulphuric
. .
ute sulphuric .d rea cts with m t ls ( l d a b ove hydrogen .1n aet1v1ty
, Reactions wit h me tal s: Dil ac1 e a P ace
d
lph ate d pro uce hydrogen.
series) to for m me tall ic shu an
Zn + H2 S0 4~ ZnS04 + H2
t
(dil)

Fe + H2S04 ~ FeS04 + H2
t
(dil)
{oxides and hyd rox ides):
, Reaction with ba ses
sal ts and wa ter.
It neu tral ise s bas es to fro m
H0
CuO + H2S04 ~ Cu S0 4 + Wa2ter
Base Acid Salt ·
0 + H20
NaOH + H2S04 ~ Na HS 4
+ 2H 20
2N aO H + H2S04 ~ Na 2 4 S0

6J Important acid as it does not ionise.

• Pure (100% H;iS0,4) hydrogen
sulphate is not an
cone. H2S04 is added to it?
mp te 4. Wh y Cu SO 4 bec om e wh ite in colour wh en
Era lisation
aus e it abs orb wa ter of crystal
e wh ite in col our wh en con e H2S0 4 is add ed to it bec
Ans. CuS 04 bec om cone.
pres ent in Cu S04-SH 20
4
) CuS 04 + SH20
250
Cu S0 4.SH 20 H

Blue (dirty white)

and Bicarbonates:
• React.ion with Ca rbo nat es bon dioxide
Acid ~ Sal t + Wa ter + Car
Ca rbo nat e/B ica rbo nat e +
S04 + H20 + CO 2 t
Na 2C0 3 + H2S0 4 ~ Na2
(dil)
Na 2S04 + 2H 20 + 2C0 2 t
2N aH C0 3 + H2S0 4 ~
(dil)

• Reaction with Sul phi des: Salt + Hy dro gen sulphide

Me tal sul phi de + Acid ~
4 + H2S t
Na2S + H2S 04 ~ Na 2S0
•
rrrr 453
sulphuric Acid t:::JIO
 • Reaction with sulphites and Bisulphite:

Sulphite/Bisulphites + Acid ~ Salt+ Water + Sulphu r dioxide

Na2S0 3 + H2S04 ~ Na2S04 + H20 + S02 t
2NaHS03 + H2S04 ~ Na2S04 + 2H20 + 2S02 t
Example S. Name the gas produced by dll. sulphuric ac1'd hi h Is poisonous in nature.
w c
Ans. S0 2 (sulphure dioxide)
Example 6. What happens when potassium sulphite react
with dil. H2S0 4
Ans. S0 2 gas is evolve d.

~ Impo rtant
· · ·
• Sulphur d1ox1de • • for II ·
1s poisonous and is therefore responsible · nment Hence it adversely affect the h
po utmg envtro · ' umon
health and vegetation.

(2) Properties of Concentrated Sulphuric Acid:

• Concentrated sulphuric acid is a non-volatile acid. It is, therefo
re, used for preparing volatile acids.
Salt of volatile acid+ Acid ~ Acid salt+ Volatile acid
(cone)
NaCl+ H2S0 4 ~ NaHS04 + HCl
NaN0 3 + H2S0 4 ~ NaHS04 + HN03
• Reaction with Non-metals

C + 2H2S0 4 ~ CO2 + 2H20 + 2S02 t

S + 2H2S04 ~ 3S02 + 2H20

itrJ lmportant
- Sulphu re dioxide gas is oxidising as well as reducing agent.
It also shows temporary bleaching property due to its reducing
nature in presence of moisture.

S02 + 2H20 ~ H2S04 + 2[H]

Nasceu t Hydrog en
Coloured mater ial+ [H] ~ Colourless product

itrJ Important
- H2SO 4 is not a strong bleaching agent as chlorine. So it
is used only to bleach delicate materials as coloure d clothe$
coloure d soft flower petals or fresh green grass.

3. As a dehydrating agent: Sulphuric acid has a

great affinit y for water. It readily removes elements of
water from other compounds. Hence, it acts as a dehydrating agent.
cone. H2S04
C12H220 11 (s) > 12C(s) + 11H 20
Sugar chareo t

CuS0 4.SH20 H2S0 4

> CuS0 4 + SH2o
(Blue) (white)
Carbohydra tE:i; Likx: glucose, sugar and cellulo se react immed
iately to give black
rises up. spong y mass of carbon which
Conc.l ~ O 4
Cb 11 12 0 [) - ~ 6C + 6H 20
Glu co se

CunL111.s04
C12 H22 O11 - ~ 12C + 11 H o
Cone sugar 2
Sugar charcoal
0

454 Ci!fJ Edu ~ art ICSE Chem istry Class X

 ~
l
I

A ,niportant
Wcone H2so4 reacts with skin to give bl'isters, because of r
,; l h • A. emoval of water and chars the skin black.
tfor Su p uric c1d
. . wit. h Barium chl
feS white prec1p1tate 'd
ltgives on e solution
BaCL2 + H2SO 4
--> Baso 4 -J.. + 2HCl
(dil)

6J 1111portant
precipitates of both BaCl2 and BaSO 4 are white but 8 S . .
,; does not. a 04 precipitate dissolves in mineral acids while BaSO 4 Precipitate

f ,csE Sugg~stions .
., srudy observation-based questions. While studyin an . .
(ormotion of precipita:es, ga~es temperature , etc. g Y chapter, stress upon related observations like colour changes,
_ Understand the meaning of relevant observations.
,.. practice writing balanced chemical equations.
-
.,
Fo cus on the colour
Practice
.
answering
I solubility. of precipitates formed us,·~~~~~
observation -based questions.
., Prepare flow diagrams, s~~rt notes, tables for facts and concepts.
., Learn the Laws and definitions well with the correct terms/key words.

( OBJECTIVE Type Questions )

Multiple Choice Question [ 1 mark ] Explanation: Cone. H2S0 4 absorbs water from
(Strictly for !CSE Semester II Exams) hydrated CuS0 4 and convert it into anhydrous
one.
1, The molecular mass of sulphuric acid is
4. When dil. H2SO4 reacts with iron sulphide,
(a) 49 (b) 98 the gas evolved is ..............
(c) 50 (d) 6.25 (a) Hydrogen sulphide
Ans. (b) 98 (b) Sulphur dioxide
Explanation: (c) Sulphur trioxide
H2S04 = (2 x 1) + (1 x 32) + (4 x 16) (d) Oxygen
= 2 + 32 + 64 Ans. (a) Hydrogen sulphide
= 98
Explanation:
2, The catalyst used in contact process is: FeS + H2S0 4 ~ H2S + FeS04
(dil)
(a) Copper
(b) Iron
S. Corrosive action of sulphuric acid on skin is
(c) Vanadium pentaoxide
due to ..............
(d) Manganese dioxide
(a) Dehydrating nature
Ans. (c) Vanadium pentaoxide
Explanation: (b) Volatile nature
(c) Reducing nature
(d) Oxidising nature
3• In the given equation identify the role played Ans. (a) Dehydrating nature
Explanation: Cone. H20 4 reacts with skin to
by Cone. H2SO4
give blistres because of removal of water, and
CuSO4.SH 2O H2504 (Conc.) > CuSO4 + SH2O
chars the skin black.
(a) Dehydrating agent
6 Promoter used in contact process ..............
(b) Oxidising agent
(a) V2Os (b) Quartz
(c) Non-volatile solid (d) K20
(c) Fe(OHh
A. (d) None of these
Ans. (d) K20
ns. (a) Dehydrating agent
0

TfI!
Sulphuric Acid f::::§Ji 455
 7. The basiclty of sulphuric aci (b) Co ncentrated Nitric aci
d Is ............ .. d
(a) One (b) Two (c) Conce ntrated Sulphuric
(c) Three acid
(d) Four (d) Co ncentrated Acetic aci
Ans. (b) Two d
Ans. (c) Conce ntrated Sulph
Explanation: Sulphuric aci uric Acid.
d ionises In two Explanati on: The other aci
stages and looses two W ds are not
dehyd rate sug ar as better
Explanation:
sulphuric acid.
as con 6le to °
H2S04 + H20 ~ H o+ centrated
3 + HS0 4-
HS04- + H20 ~ H o+
+ S0 4-
c or .
concentrated S'Ulphuri2-,·cib'(<f. ;,.
3 H2S0 4 . ,_,. ,.> ,?r cone
8. Oleum is also known as ............ , ,· Y/ / /
.. ,,
(a) Pyrosulphuric acid ,

-- ,.
j , , lM b~h.:· -
,;,,,, , .1~ '.~~hel
. ,

(b) Anhydrous sulphuric acid l\e}

(c) Oil of vitriol
w} What Examiners say
(d) ,.. Most of the candidates
None of these answered correct1
selected concentrated nitric
Ans. (a) Pyrosulphuric aci acid. y. A fev,
d
Explanation: 12. The cat aly st used in the Co
ntact Process is:
S03 + H2S04 ~ H2S207
(a) Copper [ICSE 2018}
(oleum or pyrosulphuric acid
) (b) Iron
9. The dilution of oleum result (c) Vanadium pentoxide
s in produc tion of
(a) H~ 04 (b) HCl (d) Manganese dioxide
(c) HN03 (d) None of these Ans. (c) Vanadium Pentaoxi
Ans. (a) H2S0 de
4 Explanation: The contact pro
Explanation: cess is a method
of producing sulphuric
acid in the high
H2S207 + H20 ~ 2H2S0 concentrations. The use of
4 a catalyst enables
10 . Th e sul phu ric acid rea cts law temperatures to be use
wit h NaOH to give: d in the reaction
(a) NaOH vessel while maintaining
(b) Na 2S03 a very high rate of
. reciction. Vanadium Pentox
(c) Na2S0 4 (d) None of the se ide (V20 5) is used as
Ans. (c) NaiS0
catalyst in contact process
4
Explanation: ·:'.tlJ,½' ~~~~o-~ide
2NaOH + H2S04 ~ 2H
11 . The
20 + Na2S04 /Y ,,:i; <,:; , ,·
,·,,,. ,e'.1·., ,,., ,/, _.,,
[Marking Scheme]
aci d wh ich can produc ,

cane sug
ar, is:
e carbon from
(ICSE 2020]
w-1 What Examiners say
(a) Concentrated Hydrochl _,. Most candidates selecte
d the
oric acid Vanadium pentoxide. Howeve correct option of
r, a few chose iron
which was incorrect

( SUBJECTIVE Type Que

stions)
Fill in l'h e Blanks
[ 1 mark ] 15. Sulphuric acid is a ..............
13. Sulphuric acid is also kno acid.
wn as .............. Ans. Strong
Ans. Oil of vitriol
Explanation:
Explanation:
In the later middle ages, Sulphuric acid is a strong acid
sulphuric acid was because H2S0 4
obtained as an oily viscous completely disassociates to
liquid by heating W and so /- when
crysta ls of green vitriol. hen it is dissolved in water to
ce known as oil of form an aqueous
solution.
vitriol.
14 . The arc used for production 16. The acid anhydride of sulphu
of sul phur dioxide ric acid
is ..............
gas is .............. Ans. Sulphur trioxide
Ans. Iron Pyrite (Fe S;i) Explanation:
Anhydride is formed when .
Explanation: water molecule 15
4FeS2 + 02 ~ 2Fe 20 3 + loosed by any substance.
8S 02
H2S04 -~ H20 + S02

456 Cl,, 0

Educ'ort ICSE Ch em ist ry

Class X
 11• The p~oduct formed by t
5 ugar 1s ..... ..... .... he dehydr .
,,s. sugar cha rco al
at, on of
A Explanation : t ower In con e. H
2
pyrosulphurlc acid H s o4 ,
(98%), so oleum or
C12H220 11 Conc.H 2s0½ 2 2 7
carbon ob tain ed in abo 12 S0 3 + H2S0 4 ~ H S 0 7
c + 11H2o 2 2
and ca lle d as sug ar chave rea ct"10
rcoa ole um is obtain ed.
t. n is ve ri, In t he late r middle age s, H
~ Pu re
•8• When ba rium chlorid S0 wa s obtained
" SO as an oily viscous liquid by 2 4
hea ting cry sta ls of
H2
. 4 ..... ...... ... colou r pre .rea
. ct Wi. th Co gre en vitriol, so it is known
AllS. Wh ite ec1p1tate is fi nc. as oil of vitr iol
Gyps
ormed. um ·is a sof t mineral compos
Explanati on: ed of calcium
sul pha te dihydrate. When it
is hea ted at 373K it
BaCl2 + H2 S0 4 ~ Boso l 3
ose s 2 of .its wa ter to five
(wh itep :t) + 2HCl plaster of pa ris.

19. The conversion of sul ph ur d. .d .

. 'd .
tnOXI e IS an .............. reactioiox,
h e into sulphUr
Ans. Exothermic ~ ,, 1,- -,. , : , ;',·/I''/:
24. ;,;,.:<:<??.%
, _5o,l u~ n ~CJ): -/.{ /"/,:7/t;f>,,f'
\
7y.,,, ~/,
Explanation: , '/,1 ,'Colum
, /, ;, , r /~>,;/;,-~.z n (b)
,
He at is evo lve d in the rea (i) H2S ~·

ctio n. (a) White ppt

(ii) S0 2
20. An
. explosive prepared by using s l h .
(b) Burning sulphur
IS ...... ...... . . u P uncac1.d smell
Ans. TNT (Trinitro toluene), (iii) BaS0 4
Picric aci d (c) Green ppt
(iv) Cr2(S0 4h
21. Sulphuric acid use d for ma (d) Iron pyrite
kin g fiert·l· (v) FeS2
made by the .......... 11zers •1s
.... (e) Rotton egg smell
Ans. (i)-(e), (ii) (b), Oii) -9, (iv)
Ans. Lead cha mb er proces -(c), (v) -d
s
Explanation: H2S gas gives sm
22. When ho t an d cone. ell of rotten egg .
H 2S0 4 is add ed to It is poisonous, corrosive and
sulphur, it ge t oxidised to ..... flammable.
......... S02 is an inorganic com
Ans. Sulphur dioxide (SO:i) pound, a heavy,
colourless, poisonous gas. It
gives sm ell of bur nt
Explan ati on : . ma tch es.
S + 2H 2S 04 ~ 3S 02 + White crystalline BaS0
2H 20 4 is a inorganic
com pou nd tha t is colourless
Match th e Fo llo wi ng and insoluble in
wa ter. It occurs as the min
eral barite, wh ich
[ 1 ma rk ] is the main commerical sou
rce of barium and
ma teri als poe par ed from it.
23. Chromium sul pha te is a dar
k gre en to violet
crystalline material. It is use
(i) Picric acid d pai nts and inks,
1
(a) Pyrosulphuric and in textile dying.
\ acid Iron pyrite is a mineral pyr
ite which is mo st
(ii) Ammonium \ (b) Ca S0 4.2 H2 0 abu nda nt sulphide min era
l It resembles wit h
sulphate I (c) Fertilizers gold, so the well known nick
nam e of foo l's gold.
Oii) Oleum (d) Explosive
(iv) Oil of vitriol
Tr ue / False {l ma rk ]
(e) Sulphuric acid
(v) Gypsu m
25. Sulphuric acid is a weak acid.
_ _ __
Ans. (I) -(d) , (ii) -c, ~~~~
(iii) -a, (iv) -e, (v) -b Explanation: It is a strong acid . .
Explanati on: Picric aci d is a because it is a
lso kno wn as 2, 4, 6 min era l acid.
trin itro phe
nol, pal e, ye llow , cry sta llin
is use d as a mil ita ry exp los
e solid tha t 26 . Dehydration of sugar produces
ive . CO2 gas
Am mo ni um sul phat e (NH Ans. Fal se.
4).S04 is an sul ~h at;
salt obt ain ed by rea cti Conc .H2S04 ➔ 12C
o n of H2S04 wi_t ~ Ex pla nat ion: Ci 2H220 11
Volu me s of NH . It is wid + l lH20
3
ely use d as a fertili zer.
When sul phu r trio xid e
is coo led in hea t It pro duc es car bon .
exc han ge and is the n abs
orb ed in abs orp tio n
0

su lph ur ic Acid 1:::§1 JII!_ 45 7_

 27. The gas produced by reaction betw
een - 04 ~ NaHS04 + Hct
Ans . NaCl+ H2S
(cone )
sodium sulphite and dll. H2S04 ls S02
,
Ans. True. 41. C + H2S0 4 ~
Explanation : Na 2S0 3 + H2S04 - 4 (cone)
Na2S0 4
(dll) Ans. C + 2H2S04 ~ CO2 + 2H20 +
2S0 2
42. Preparation of Copper sulphate
28. Sulphuric acid is a diba lsic acid . Neutrllzatlon. [ICSE by
Ans. True Ans. Copper sulphate by Neutralization 20 20
1
Explanation: It releases two hydrogen ion. CuO + H2S0 4-- , CuS04 + H 0
2
29. Picrlc acid is an explosive. (Copper sulphate)

Ans. True. , ·. C\,AO + H,2~04 -- -'- +CuSO 4 + H o

2
.or ,Cu(OHh ~ ~2so.~--, CuS04 + 2H2 0
Complete and Balance the following ,, ,, , ,.,,, :,, ,~/''I' ' ,; ,
: ·; :: /0-/4!';-i.✓, • - .: [Marking scherne]
equation .'P ,/,1/1:t,, ✓,.-,,,;/, .;>.,,.
[ 1 mar k]
~ What Examiners say
30. S02 + H20 + 02 -4
..,. Most of the candidates matched
Ans. 2S0 2 + 2H 20 + 0 2- 4 2H S0 the salt . ,
2 4 the preparation mistead of writing
.d bala Wi th
equations. Same can dt ates use d copp
31. FeS2 + 0 2 - 4 er suiphneed
as the reactant or used sodium sulphate
Ans. 4FeS2 + H02 - 4 2Fe203 + 8S0 misteadatef
2 sulphuric act'd. o
32. S02 + 02 -,
43. Preparation of Ammonium sulphate by
Ans. 2S02 + 02 Titration. [ICSE 2020]
Ans. Ammonium sulphate by Titration
33. S03 + H2S04 - , 2NH40H + H2S 04- -, (NH4)S04 + 2H
0 2
Ans. S03 + H2S 04- -, H2S207
(Ammonium Sulphate)
f!;/, r ,,, ✓,, , .
34. H2S207 + H20 --, ' ,: ~tl'/ ; ,:> (N~2hS04 + 2H o
2
Ans. H2S207 + H2 0-- , 2H2S04
, ,
}{r; [Marking Scheme]
35. Mg+ H2S04
(dil)
--,
wJ What Examiners say
..,. Either the reactants selected were
Ans. Mg+ H2S0 4 - , MgS04 + incorrect. or
H2i formula for ammonium sulphate writte
(dil) n was
incorrect in some cases.
36. CuO + H2S0 4 -, 44. Action of dilute sulphuric acid on
(dil) sodium
hydroxide. [ICSE 2019]
Ans. CuO + H2S0 --, CuS04 + Ans. 2NaOH + H2S0 --, Na S0
4 H20 4 2 4 + 2H 20
(dil)
~' :2Na9H\ 8j so~~ Na2S04 + 2H20
37. NaHC03 + H SO - - , ' ,, ' '\>' ~ " -. \._, ~( '-, '
2 4 ·· ·
(dil) '\
· . .. [Marking Scheme]
Ans . 2NaHC03 + H2S04 - , Na S0 45. Action of dilute sulphuric acid on zinc
2 4 + 2H 20 sulphide.
(dil) + 2C02 [ICSE 2019]
Ans. ZnS + H2S0 4 ~ ZnS0 + H
38. Fes + H2S04 --, 4 2S i
(dll) ZnS + H2S0 4 ~ ZnS0 4 + H2S-.l.
Ans. FeS + H2S0 4 --, FeS04 + H2S [Marking Scheme]
39. NaHS03 + H2SO 4 - - , ~ Wh
~
(dll)
at Examiners say
..,. Serveral candidates represend zinc
Ans. 2NaHS0 3 + H2S0 4 - , Na2 sulph ide
S04 + 2H20 incorrectly as ZnS0 or ZnS0 •
4 3
(dil)
46. C + cone. H2so ~ [ICSE 2019]
4
+ S0 2i Ans . C + 2H2S0 4 ~ 2H 0 + CO +
2 2 2S0 2
40. NaCl + H2SO 4 --?
(cone) C + 2H2S0 4 ~ CO 2 + 2S0 2 + 2Hi0
[Marking ScherYlel
0

45 8 Cl/, Educ;'art ICSE Ch em istr y Clas s X

r 0J w1iat Examiners say
'fl' h ugh CO2 was the product St• Action of concentrated sulPhuri·c acid on
"" ~:o:e H2C03. , serveral candidates carbon. [ICSE 201 41
caution Ans. C + 2H7 S0 4 , - . CO 2 + 2H20 + 2S0 2
!> ..,, pro
eqLl
ctice adequately in writing of b l
O
tions with necessary conditions
a anced h
c ernical
(cone.)
S2. Dehydration of concentrated sulphuric acid
.
With sugar crystals. [ICSE 2013]
11. tion of concentrated sulphu . Ans. C12H220 u. + [H 2S0 4] - , 12C + [H 2S0 4 +
1, ,,.c ric acid on
' carbon. [ICSE 2018] (con e.) l1H 20]
C+ 2H2S0 4 ~ CO2 + 2H20 + 2S0 5 3. Zinc sulphide and dilute sulphuric add.
A,,s. 2
c + 2H 2S04 ~ CO2 + 2S0 2 + 2H 2o [ICSE 201.2]
[Marking Scheme] Ans. ZnS + H2S04 ~ ZnS0 4 + H2S.

W1 What Ex~miners say Write down the observation

.,. MonY candidates erred by writing H2so3 or H CO [ 1 m ark ]
2
. 3
o....,,,,0 ng the products. Some left the equation 54• Iron reacts with dil. H2so 4
unbalanced. A few wrote Cu mistead of c.
Ans. Fe+ H2S04 ~ FeS04 + H2 j
'8, preparation of Copper sulphate from copper (dil)

carbonate.
A gas is evolve which gives pop up sound.
[ICSE 2018]
55. Sulphuric acid reacts with sodium hydroxide
Ans. cuC0 3 + H2S04 ---: CuS04 + H20 + co 2 in excess.
CuC03 + ~2S04 ~ C~S04,7 ~ 20'1, .c&~:J: Ans. 2Na0H + H2S04 ~ Na2S04 + 2H20
' ': ,_'~\ '· ., ',[Marldng:schi!;ij!;
r'v..~,, w~~::Z,t~w>,
~1,- , , j- ,; ';
(dil)

Sodium sulphate will form.

W-J What Examiners say 56. Sodium carbonate reacts with dil H2SO 4
• Misted of reaction with H2S04, a few candidates Ans. A gas evolves with brick effervescence.
used Nai$0 4 solution. Some candidates wrote two
equations, first using HCl and then using H2S0 4. Na2C03 + H2S04 ~ Na 2S0 4 + H20 + CO 2
(dil)

49. Action of concentrated sulphuric acid on 57 • Zinc sulphide reacts w ith dilute sulphuric
Sulphur. [ICSE 2017] acid.
J;ns. S + 2H2S0 4 ~ 3S0 2 + 2H20. Ans. ZnS + H2S0 4 ~ ZnS0 4 + H2S i
, ,y ¢;., ". ·m. , , , 'ft,_,, (dil)
S + 2H2 _,, ·
' ' A gas evolves w ith rotten egg s mell
58. Sodium sulphite reacts with dilute H2SO4
Ans. Na2S03 + H2S0 4 ~ H20 + S02 + Na2S04
~ What Examiner~ say (dil)

-. In some cases, ~he products were incorrect. Some A gass evolves w ith smell of buring sulphur.
wrote the reaction of S with concentrated HN03
mistead of concentrated H2S0 4 indicating not having
59. Sulphur react with cone. sulphuric acid
read the question carefully. Ans. S + 2H 2S0 4 ~ 3S0 2 + 2H20
so. Acti on of dilute Sulphuric acid on Sodium
A gas is envolved w ith smell of buring sulphur
Sulphite. [ICSE 2016] 60. Cone. H 2S0 4 is added to sugar
Aris. Na SO
2 3 + H2S0 4 ~ Na 2S04 + H20 + S0 2 Conc. H2S04 > 12C + 1lH20
Ans. C12H220 11
Na2S0 3 + H2 so·4 ~ Na2S0 4 + H20 ➔• $0 2 Suga r crystals becomes black in colour.
[Marking Scheme) 61. Cone. H2so4 15 added to Blue vitriol
~ What Ex · Ans. CuS04.S H20
Conc. H2S04 > CuS04 + SH 20
~ . am1ners say
Either th . The blue copper sulphate convert into w hite
Na S e acid chosen was HCl mistead of H2S04 or
2 after loosing wate r molecule.
the d~ Was take~ as Na 2S. Candidat~s failed t~ see
rence sodium sulphite and sodium sulphide.
0

C.- o ■ l n hm-i
rrrr 45n_
 ~ What Examiners say
62. Cone. Sulphuric acid is treated with barium -. candidates mentioned formation of su
chloride solution. or carbon without stating its appeara:C~ cha,eo01
8
Ans. BaCl2 + H2S04 ---, BaS0 4 ! + 2HCl them described the observation as deh · orrie Of
White precipitate of Barium sulphate is formed. sugar which was incorrect. Ydration Of

63. Potassium bicarbonate react with dilute & caution

-. Understand the fact that identification f
sulphuric a cid.
and starting the observations are two diff: Productti
rent th·ll')g\
Ans. 2KHC03 + H2S0 4 ___, K2 so 4 + 2H 20 + 2C02
A gas evolved with brisk effervescence. Give Reasons [ 1nn;irv ]
64. Action of concentrated Sulphuric a cid on 68. Why sulphuric acid is also called the 'ki
hydrated copper sulphat e. [ICSE 2017] chemicals'? ng Of
Ans. On reacting hyd rated copper sulphate with Ans. Sulphuric acid is called the king of che .
h . h rn1ca~
concent rated sulphuric acid, blue coloured because dt erh~ his . no dot ber manufatured
copper sulphate t urns white .. compoun w 1c 1s use y such O lo
number of key industries. · r%
Chemical Equation:
CuS0 4.SH 20 H2S04 CuS0 4 + SH 20 69. Why sulphuric acid is known as oil of vitri0,1,
Ans. It was obtained as an oily viscous liquid b
heating crystals of green vitriol Hence it 15_Y
known as oil of vitriol. '
70. Platinum is more efficient as a catalyst than
Vanadium pentaoxide. Still V20 5 is used as 0
~ What Examiners say catalyst.
-. Most candidates ignored the colour change or the Ans. Platinum is more efficient as acatalyst than
change from the crystalline state to amorphous V20 5 but platinum is more expensive and also
state and mistead mentioned the phenomenon of it easily get poisoned by impurities Like arsenic
dehydration or the formation of anhydrous copper
oxide.
sulphate.
I 71. How sulphur dioxide is responsible for
65. Concentrated Sulphuric acid is added to polluting environment?
Sugar Crystals. [ICSE 2016]
Ans. Sulphur dioxide is poisonous and is therefore
Ans. Black spongy mass is formed.
responsible for pollu~ing environment
Chemical Equation:
72. Why sulphur dioxide is an oxidising as well as
C12H22011 H2S0 4 12C + 11H20 reducing agent?
66. Concentrated sulphuric acid is added Ans. Sulphur dioxide gas is oxidising as well as
dropwise to a crystal of hydrated copper reducing agent It also shows temporary
sulphate. [ICSE 2013] bleaching property due to its reducing nature
in presence of moisture.
Ans. Crystals of hydrated copper sulphate turn
S02 + 2H20-----+ H2S04 + 2[H]
white and amorphous.
73. Why sugar gets black in colour when cone.
Chemical Equation:
sulphuric acid is added to it?
H2S0 4
.
Cuso 4- SH 2 O dehydrating C SO 4 SH 0 Ans. When cone. sulphuric acid is added to sugar t
agent u + 2
absorbs the water molecule and sugar becomes
67. In the given equation identify the role played black in colour.
by concentrated sulphuric acid C H O · Cone. H2S04 12C + 11HP
12 22 11
S + 2H 2S04 ---? 3SO2 + 2H2O [ICSE 2013]
74. Why cone. H 2SO 4 give blister on skin?
Ans. Oxidising agent
Ans. Cone. H2S04 reacts with skin to give bli5Cers
Explanation: Sulphur is oxidised to Sulph ur
because of removal of water and chars the skin
dioxide by Sulphuric aci d which acts as an
black.
oxidising ag ent.
75 • Why the potassium dichromate becomes
Sugar chars to give black porous mass. ·0xide
orange to green colour when sulphur d
1
[Marldng Scheme]
is passed on it?

460 ldl!, Edu i:ort ICSE Chemistry Class X

 turns a 'd•fi
Ar,S• Sulphur dioxidel . c1 11ed . colourle ss
r dichromate so ut1on green b Potassium 84• Name the tolutlon which turns h
. d . ecause l h
dioxide possess re ucing property su p ur when sulphur dioxide gas Is passed throug
K2cr2O2 + H2S04 + 3SO 2 ~ Cr (S
It?
(orange) 2 04h
green Ans. Potassiu m Pormagnate. It become s colourless
as S02 possess bleaching property .
+ K2S0 4 + H20 to obtain
85. Name an acid that can't be used
State why concent rated sulphur,· c ac1d •1s n0 t
16• used for drying
·
ammon ia gas [ICS
S02, from sulphite
· E 2018] Ans. Nitric acid, as it do not possess sulphur.
s. conentrated Sulphur ic acid cannot b
A11 • e used for 86. Give the chemical name and common name
. 1 ammoni.a
drying ammonia gas as it reacts w"th
of reagent used in photographic work.
.
farming ammoni um sulphate.
Ans. Sodium thiosulphate (Na 2S2O3) is used in
Concentrated .
sulphuric acid reacts with photography
. . , .. , . .
ammoni a/from ammon ium sulphat N
. b . . e or H3 87• Name an orange colour solution which turns
being as,c cor:nb1nes.. with coneent rated in green colour when sulphur dioxide gas is
H2So 4· · ' ·
passed through it
[Marking Scherri~l Ans. Potassium dichromate get converted from
orange to green.
W-J What Examiners say 88. Process by which sulphur is boiled with
-. Most candidates answered this question correctly. rubber.
Name the follow ing [ 1 mark ] Ans. In vulcanization of rubber sulphur is boiled with
rubber.
77, Name the catalys t used using contact
process. 89. Name the acid which produces sugar
charcoal from sugar. [ICSE 2015]
Ans. During the contact chambe r process vanadium
Ans. Cone. Sulphuric Acid (H 2SO 4)
Pentaoxide (½Os) or platinum is used as
catalyst. 90. Name the acid on mixing with lead nitrate
solution produces a white precipitate which
78. Name the promoter used in contact process. is insoluble even on heating. [ICSE 2015]
Ans. K2O is a promote r which enhance the working Ans. Sulphuric Acid
ofV2O5. Explanation:
79. Give the atomicity of sulphur. H2SO4 + Pb(NO3h ~ PbSO 4 + 2HNO3
(white)
Ans. The molecular formula of sulphur is S8. Hence
its atomicity is 8.
Short Answ er Type Questions
80. Give the basicity of sulphuric acid [ 3 mark]
Ans. Sulphuric acid (H 2S04) loses 2 hydrogen ions
91. Distinguish between Calcium nitrate and Zinc
(W). Hence it has basicity two.
nitrate solution using a reagentas a chemical
,21. Name the acid obtained by dissolving sulphur test. [ICSE 2020]
dioxide in water. Ans. Calcium nitrate and Zinc nitrate solutions con b~
Ans. Oleum is an acid formed when H2SO4 is diluted distinguished from each other by adding dilute
by water. sulphuric acid (H 2SO 4) to both the solutions.
Calcium nitrate forms a white precipitate while
H2S04 + H20 ~ H2S207
Zinc nitrate does not form any precipitate.
82. Name the block coloured substan ce formed
when sugar is dehydrated. NaOH/KOH/ dil. H2SO 4 to both the solutions.
Calcium nitrate forms a white precipita te
Ans. When sugar is dehydra ted by concentrate
whi ch is insoluble in excess of NaOH white
sulphuric acid, only carbon get remained zinc nitrote forms o gelatinous white
C12H22011 conc,H2S0 4 ➔ 12c + 11HP precipitote soluble in excess.
Wi th (dilute) sulphuric cicici; Colcium nitrate
83• Name the bleaching agent used to bleach forms a whi te precipita te white zinc nitrote
A. delicate articles. does not fo rm precipitate.
l'ls. Sulphur dioxide is used to bleach delicate (Marking Scheme]
articles.
0
. JfI!_
Sulphuric Acid t::£::J 461
 ~ What Examiners say
"wJ What Examiners say candidates wrote dring mistead of deh
.,. A num bero f candidates chose the correct Heagent. -. Some . . Ydror1
-. Sever;al candidates stated ac1d1c property ,·nstead ori
92. Distinguish between Dlsting~ish between oxidising property. of
Dilute hydrochloric acid and dilute sulphuric
acid. (using lead nitrate solution) [ICSE 2019] &.,. Caution .
St dy about the behaviour of
Ans. Lead Nitrate solution reacts with dilute sulphuric acid . .
u and concentrate d fi
'lute d ,ts
· volatile n in 'ts
hydrochloric acid to give white precipitate d1 orms, an
ature.
of lead chloride which dissolves on heating
On adding light nitrate solution, if wh·
whereas on reacting dilute sulphuric a cid with
'?r":e d w h'ic h d'issolves lte
• .c .
precipitate is. on
lead nitrate solution an isolu ble precipitate of
heating, then 1t 1s dilute HCl.
lead sulphat e is fo rmed which does not dissolve
If white precipitate formed does n
furth er.
dissolve on heating it is H2S04. ot
Explanation:
Pb(N03)i + 2HCl---? PbCl2! + 2HN03 [Marking Scheme}
(white ppt.)
(Insoluble in cold water but dissolv~s in warm
,9)1 What Examiners say
-. White precipitate was mentioned by servero(
water) candidates but the effect of heat on both was not ,,r;,J
,;
Pb(N03)i + H2S04---? PbS04 + 2HN03 mentioned. ' I
r., e
(white ppt.)
(Insoluble both in cold and warm water)
95. How will you distinguis h between dilute ~ I
hydrochloric acid and dilute sulphuric acid i ~f SI
93. Copy and c9mplete the following table using lead nitrate solution? [ICSE 2017]
which refers to the industrial method for the
preparation of sulphuric acid: Ans. On adding lead nitrate solution to dilute
hydrochlo ric acid a white precipitate is
' formed which is soluble in hot water.
Name of the<;, .
compound · · :· On adding lead nitrate solution to dilute
,! ·,. Sulphuric acid a white precipitate is formed ~' 101
w1
Sulphuric acid 1 which is soluble in hot water.
((
[ICSE 2019] ? ~i~gf tedd nitrate solution to both,
Ans. (A) Contact process ,Jm;:Wnit:e -precipitate but the one in
' · · · hite precipitate disappears on
(8) 2S02 + 02 V2Os 2S03

(A) Contact Proce:;,

(B) 2S02 +·02 05
>· 2S03··· ·. . :".r ·
•>~lJ "~Cl, 'while in H2S04, the white
. remains insoluble on heating.
[Marking Scheme]

' , '_·.;·.:: ::: ·-✓-lr~tai.~~~~~t~,rp'.~ti ,9)1 What Examiners say

~ What Examiners say ~ Many candidates failed to correctly distinguis/-
between dilute HCl and dilute H~0 4 as the solubility
• Some candidates wrote Haber's process instead of of white precipitate formed with HCl on heating
contact process. was not included and mistead, formation, of brown
,6 Caution N02 gas with H~0 4 was mentioned which was not
possible.
-. Study industrial method for preparation of sulphuric
acid thoroughly.
96. Write balanced chemical equations to show
94. Which property of sulphuric acid is shown by how S03 is converted to Sulphuric acid in the
the reaction of concentrated sulphuric acid contact process. [ICSE 2017]
with: Ans. S03 + H2S0 4 ~ H S 0
(A) Ethanol? 2 2 7
oleum
(B) Carbon? [ICSE 2018] .
Ans. (A) Ethanol: Dehydratin g agent H2S207 + H20 ~ 2H 2S0 4
(B) Carbon: Oxidising agent.
S03 + H2S04 ~ 'H2S2o':,
(A) Dehydratin g agent/deh ydrat ion cone.
(B) Oxidizing agent/oxid ation H2S207 + H20 ---? 2H2S04
[Marking Scheme) [Marking Scheme]

462 Cl!:; Edu ~ art ICSE Chemis try Class X

r
0J What Examiners say
fl' nY candidates forgot the two (4) MgO + H2S04 ~ MgS04 + H20
,.,tf,t/Oa to H2S04 through the fo rrnast~ep conversion of
S 3 . . h Ans. Dilute acid
diluting it ,n t. e secon d step. Mistead
ion of ale
urn and
0 directly with water to get sulph . ' they treated (5) Zn + 2H2SO 4 - >ZnS04 + S0 2 + H2 0
S 3 uric acid. (cone.)
A caution
/)> Understand oxidising action of sulphuric ._ . Ans. Oxidising agent
_. for better understanding. ac,d 111 steps (6) NaCl + H 2 S0 4 ---► NaHS04 + HCl
Understand the outcome of adding w t Ans. Non-volatile acid.
_. trioxide in the contact process. a er to sulphur
(7) N02C0 3 + H2S04 ~ N02S04 + H20
Differentiat between Dilute sulphu . . + CO2
91• d h ric acid Ans. Dilute acid
and dilute h~ roe Lorie acid (using barium
chloride solut i~n). [ICSE 2014] 102. (A) NCl, HN03 and H2So4 are the formulae of
Barium Chlori de on reacting with d'l three compounds which of these
ArtS- . 'd s:: h' 1 Ute compounds has the highest boiling point
sulphuric ac1 1orms a t 1ck white precipitat
which is insoluble in Nitric acid. e and which has the lowest?
BaCl 2 + H2S04~ BaS0 4 + 2HCl. (B) Oil. HCl and dil. H2S04 are both colourless
white ppt solutions. How will the addition of barium
Barium Chloride on reacting with dil HCl has chloride solution to each help to
no effect. distinguish between the two?
Ans. (A) H2S0 4 has the highest boiling point HCl
98, State any two conditions for the conversion
has the lowest boiling point.
of sulphur dioxide to sulphur trioxide.
(B) Oil. H2S0 4 on reaction with BaCl solution
[ICSE 2014] gives white, precipitate which is insoluble in
Ans. Vanadium Penta oxide or Platinum as Catalyst all mineral acids, whereas with HCl there
and temperature of 450°C - S00°C and 2 is no reaction.
atmospheric pressure.

99. Identify a dilute mineral acid which forms a

103. Write balanced chemical equations to show:
white precipitate when treated with barium
(A) The oxidizing action of cone. Sulphuric acid
chloride solution. on Carbon.
[ICSE 2013]
(B) The behavior of H2S04 as an acid when it
Ans. H2S0 4 (d ilute) [dilute Sulhpuric Acid]
reacts with Magnesium.
Explanation:
(C) The dehydrating property of cone. Sulphuric
H2S0 4 + BaCl 2 ~ BaS04 + 2HCl
acid with sugar. PCSE 2017]
white ppt
Ans. (A) C + 2H 2 S0 4 ---► CO 2 + 2H20 + 2S02 i
100. Hentify the gas produced on reaction of
(B) Mg + H2S04 ~ MgS04 + H2 i
dilute sulhpuric acid with a metallic sulphide.
[ICSE 2012] cone H2S04 ) C + l1H O
12 2
Ans. Hydrogen Sulphide gas.
Olemical Equation:
Na2S + H2S0 4 ~ H2S + Na2S04
1.0t Some pr.operties of sulphuric acid are teste_d
bet.ow. Choose the role played by sulphuric
acid as ~ B, C, D, which is responsible for th e [Marking Scheme}
reactions.
(A) Dilute acid (B) dehydrates agent
(q Non-volatile acid {D) Oxidising agent 'fo7J What Examiners say .
• Most of the candidates either ~rote incorrect
-~ -4 '➔ CuS04
10
(1) CuS04-5H 20 -Conc.H2 products or did not balance the equation.
+ SH20 • Many candidates wrote the formula for sugar as
Ans. Dehydrat ing agent
c6 H12o6 (glucose) which is incorrect.
(2) S + 2H 2SO 4 ~ 3S02 + 2H20 &• Caution
Understand the difference
(cone.) in produc~s formed when a
metal/metal oxide reacts with an acid.
Ans. Oxidising agent
(3) NaN03 + H2S04 ~ NaHS04 + HN03 104. A B, C and D summarise the propertie~ ~f
' 1
sulphur c ac id depending on whether 1t 1s
(cone.)
dilute or concentrated.
Ans. Non-volatile acid
rrI!_
Sulphuric Acid 1:4111 463
 A = Typical acid pr?perty
B = Non volatile acid
c = oxidizing agent
0 _ Dehydra
ting agent r:il What Examiners say
c~ose the property (A, B, C or D) depending ~
• _. Few can
d/ates m ade the error by giving the Produc,:
on which is relevant to each of the following: KHS04 or H2C0 3
{!) Preparation of Hydroge n chloride gas. GI one equation each to show the follow·
(2) Preparation of Copper sulphate from 10 6• ve rtles of sulphuric acid: lflg
. prope
copper oxide. (A) Dehydrating property.
(3) Action of cone. Sulphuric acid on Sulphur.
[ICSE 2016) (B) Acidic nature.
(C) As a non-vola tile acid. [ICSE 20141
Ans. (1) Preparation of HCl gas Dehydra ting Nature of H2S0 4
NaCl + H2S0 4 -----4 NaHS04 + HCL Ans. (A)
e,e H1p 6 +[cone H~4]-- -4 6C +6H20 +[¾4j
Non volatile Acid (B) Black re sidue
(2) Prepardtion of CuS04 from CuO
(B) Acidic Nature of H2S04
CuO + H2S0 4 -----4 CuS04 + H20
H2S04 + K2C03 ~ K2S04 + CO2 + H20
Typical Acid Property (A)
(3) Action of Cone. Sulphuric Acid on Sulphur
(C) As a Non volatile Acid
<200°C
S + 2H 2S0 4 -----4 3S02 + 2H20 Na + H 2S0 4 _ ___, NaHS0 4 + HCl

Oxidizing Agent (C) (volatile Aci<fJ

"" - ./'
1
(1) B or non-volatile acid ., : :'' · : ~· ' , ;, ' 107. Some properties of sulphuric acid are Listed
(2) A or typical acid propertyi: '1 , ·> . below. Choose the role played by sulphuric
,,,,:,,,,
., , .;
(3) C or oxidizing ptope~ty{a9,.E;!nt,, ~.: •:;:.,::h·~r,{
,':1'it'~t..; "~;
acid as A, B C or D which is responsible for
, it

. , /\'
1
"J'--16rkjng;Sc~emeJ ; the reactions (1) to (v). Some role/s may be
, '- /· ., , ! , ; ~/4._..,,' .,( \' , · . -~ . p $'' / • 'l

repeated.
,s?J] What Examiners say (a) Dilute acid
"- (1) chosen as a typical acid or as an oxidising
H;zS04 (b) Dehydrating agent
agent mistead of its behaviour as a non-volatile
add. (c) Non-volatile acid
(2) Candidates suggested the property of H2S04 (d) Oxidising agent.
as a dehydrating agentfoxidising agent mistead Conc.H2S04
of its acidic nature. (1) CuS04.SH20 CuS04 + SH20
(3) Many candidates erred by stating dehydrating (2) S + H2S04 (cone. )~ 3S02 + 2H20
property/typical acid property mistead of its
oxidizing property. (3) NaN03 + H2S04(conc.) <2 00°C )

& Caution NaHS0 4 +HO

• HCL is a volatile acid and hence to avoid contamination
with substances such as moisture cone. H2S04 is used (4) MgO + H2S04 ~ MgS04 + H20
as a non-volatile acid. (5) Zn+ 2H 2S04(conc.) ~ ZnS0 4 + S02
105. Give balanced chemical equations for the + 2H20
action of sulphuric acid an each of the [ICSE 2012}
following: Ans. (1) CuS04.SH20 Conc.H2S 04 CuS04 + SH~O
(A) Potassium hydrogen carbonate.
(b) Dehydra ting agent
(B) Sulphur [ICSE 2015]
Ans. (A) (1) 2KHC03 + H2S04 - - - j K2S04 + 2H 20 (2) S + 2H2S0 4(conc.) ~ 3S0 2 + 2H20
+ 2C0 2 (d) Oxidising agent.
(2) S + 2H 2S04 - - - j 3S02 + 2H20 <200°C
(B) (1) S03 + H2S04 ~ H2S20 7 (3) NaN03 + H2S0 4 - -- ~ NaHS04+ HC!
(2) H2S207 + H20 ~ 2H 2S04 (c) Non-Volatile Acid.
(A) 2KHC03 + H2S04 ---+ K2S04 + 2H20 ( ) MgO + H2S04 ~ MgS0 4 + H20
4
+ 2C0 2 (a) Dilute Acid.
(v) Zn+ 2H2S04 (cone.) ~ ZnS04 + S02 + 2Hz0

0
Jrl!_ ,- _._ _,-J_ _.. ,,.cl: r-""a""i,,. ..... ,-, ____ V
(d) Oxidising agent.

~-
 Organic
Chemistry

Carbony l
gro up

Garlic

f1'f?~
~-
Organic chemistry deals with che
mical compounds that contain
to life. Organic chemists study carbon , an element considered ess
the composition, structure, pro ential
which along with carbon, contain perties and reactions of such com
other non-carbon elements suc pounds,
Organic chemistry is used in ma h as hydrogen, sulfur and silicon.
ny applications, such as biofech
pharmaceuticals and plastics. nology, the petroleum industry,

C ha pt er Topics
il Organic Compounds
il Structure and Isomerism
il Writing Structural Formula Fro
m /UPAC Name
il Alkanes

il Alkenes
il Alkynes
 ITOPIC1 I
ORGANIC COMPOUNDS
. try was known, people thought th
l l'ttle chem1s l" ot
. . l'fi When com parative y ' l from living sources ike plants a d
nic means pertaining to I e. obtained on y .. . n
The word orga . nd acetic acid could be ds derived from l1v1ng organisms, and
substances like sugar, starch, protein a . mpounds, the compoun
ll d such substances organic co
animals, so, they ca e d organic chemistry.
the chemistry dealing with them was name

,...-1, Important . l'eved that they were the products of some vital
dJ'-1" .h fr, nature ,t was be ,
,. Since organic compounds were obtained stra,g t om .
force of nature.

Sources of Organic Compounds al drugs are obtained from plants.

. d ll lose as well as sever ,
• Plants: Compounds like sugar, starch, an ce u ,
. bt . ed from animals.
• Animals: Urea, proteins, fats etc. are O ain h l ne dyes drugs, perfumes etc.
d b ene toluene, napt a e , ,
• Coal: Destructive distillation of coal pro uces enz ' b . d from petroleum
l neptha etc are o taine .
• Petroleum: Compounds like gasoline, fuel gases, petro ' f H d b d
. • h d ls with the study o y rocar ons an the
• Organic chemistry is a special branch of chemistry whic ea
basic derivatives of carbon. .
.
• The Vital force thoery was given earlier to explain the concep t 0 f organic compounds, but after discovery of
urea, the theory was discarded.
•
• The first organic compound discovered was urea. 1twas prepa red from Ammonium cyanate.
NH 4CNO ~ NH2CONH2
(Ammonium cyanate)

Unique Nature of Carbon Atom

• Catenation: The property of self-linking of atoms of an element through covalent bonds in order to form
straight chains, branched chains and cyclic chains of different sizes is known as catenation.
• Tetravalency of the carbon atom: Carbon has four valence electrons. Since it can neither lose nor gain
electrons, hence, for completion of octet, it forms covalent bonds. This is known as tetravalency of carbon.
• Multiple Bonding: Due to its tetravalent nature carbon is capable to form single, double and triple bond.
I I
-C-C- -C=C- -C=C-
1 I 1 I (Triple bond)
(Single bond) (Double bond)

Hydrocarbons
The compounds formed by the combination of hydrgoen and carbon onl k Th
. .
are the simplest organic compounds. Other organic compounds are the b Y· are nown as hydrocarbons. ese
d • .
as1c envat1ves of Hydrocarbons.
Hydrocarbons
-l,
r
Aliphatic (open chain) i
t Aromatic (closed chain)
Saturated Unsaturated
or -l,
Paraffins
or Alkenes (Olefin s)
Alkanes Alkynes

0
JrI_r
466 c:11 Edu~art ICSE Chemistry Class X
 oted Hydrocarbons called
5~t1Jf in which the all fi . b d onely, are f
drocarbons our valencies of carbon is satisfied by single on l fi rmula 0
rne n~ed hydrocarbons. These are also known as Alkan es or Paraffins. The genera ho ne) C2H6
soturll is CnH2n +2 [where n = 1• 2 ........]. Alkanes gives substitution reactions only. Eg. CH 4 (M et a '
AikOr,es
cnorie)
~ turated Hydrocarbons
U~sO l The general
• Alkenes: When any. one va ency of carbon is satisfied by double bond, it is known as Alkenes.
formula of Alkenes is CnH2n• [where n = 2, 3 .......]. Alkenes gives addition reaction
CH2 = CH2 ; Ethene
(C2H4)
CH 3-CH = CH2 ; Propene
(C3Hs)
• AlkYne: Vv'.hen any valency of carbon is satisfied by triple bond it is known as Alkynes. The general formula
of Alkyne 1s CnH2n - 2 =2 [where n =2, 3 ....]. Alkynes give addition ractions.
E.g. CH = CH ; Ethyne
(C2Hv
CH3-C = CH ; Propyne
(C3H4)

STRUCTURE AND ISOMERISM

Stn,1cture
Hydrocarbons are usually represented by their structural formula.
The formulae that shows how atoms of different elements are linked together in a molecule is known as
;tn.1ctural formula.

&ample 1. What is the structural formula of Butane?

Ans. Butane (C4H10) can be represented as :
H H H H
I I I I
H-C-C- C-C-H
I I I I
H H H H
• Amolecule having the bigger structural formula is represented by abbroviated formula.

~Abbreviated formula of Butane

Ana, CH3 - CH2 - CH2 - CH3
• Astructure that show only the linking of carbon atoms in a molecule is called the carbon skeleton.

~ 3. Carbon skeleton of Butane

Ana. c-c- c-c.
Isomerism
T~e compound having similar molecular formula but different structural formula are called isomers and
P
t his
nenorn .
enon is called isomerism.
Isomerism
t
Structural Stereo or space
t i
C~---.:i--___.:_..,... J, _ _ __,i i,.....-_ - ----.-1,

ltnp 0 hain Position Functional Metamerslm Geometrical Optical

·
rtant isorn ers different · or bot h.
· properties
in physical or chemical

.
. Chem1stry
0 rgamc JrI! 467
t:::f'S
 of following compounds:
Write the structure
£,campl• 4•
(1) 2, 2-dimeth!:ll butane
(2) But-2-!:lne
cH - cH - CH - CH 3
3 I I
Ans. (l)
CH 3 CH 3
CH 3- C = C- CH 3 t are different in the
(2) . ,'la r mo lec ula r formula bu
0 pounds
have s,m
d h0 ·ns t he com pou nds
are referred to as h .
,
o or mo re c m c 0111
• Chain lsom ers ,m: Tw atoms in straight or bra nche .c ' '
arrangement of carbon · · mensm ·
is termed as cha,n ,so
isomers and the phenomenon
CH3
E..g. : C5H12 CH3- CH2-C H2 -CH 2-
Pentane
1 2 3 4
CH 3-C H- CH 2- CH3
I
CH3
2-Methylbutane
CH3
1 2I 3
" CH 3-C -CH 3
I
CH3
2, 2-Methyl propane
ite the chain isomers of it.
alk:ane having molecular mass 86 i.s given to you. Wr
Example 5. An
Ans. CnH2n + 2 = 86
(12 x n) + (2n + 2) x 1 = 86
14n = 84
n =6
Molecular formula = C6 H14
2-C H 3
CH 3-C H2 -CH 2-C H2 -CH
hexane

5 4 3 2 1
CH 3-C H2 -C H2 -C H- CH 3
I
CH 3
2-M eth ylp ent ane

5 4 3 2 1
CH 3-C H2 -C H- CH 2-C H 3
I
CH 3
3-M eth ylp ent ane
CH 3
I
CH 3-C H2-C -C H3
4 3 2I 1
CH 3
2, 2-d ime thy lbu tan e

4 3 2 1
CH3- CH- CH- CH3
I I
CH3 CH3
2, 3-dime thylbu tane

• Position isomerism: Wh
en two or mo re
. . compounds With th e sam e molecular formula differ in the
.. f fun ctional group on th d
position o sub strt·uen t ato
d
m of
•. e carbon at om , t hey are called position isomers an
this ph enonenon ls terme as position isom eris m.

0
1.r_irrr
468 c: ry Class X
18 Ed uc 'ar t IC SE Chemist
 1 2 3 4
CH3 - C = C- CH 3
E.g.: But -2-yne
4 3 2 1
CH3 -CH 2- C ;;;; CH
and
But-1- yne
re given to the
enclature the IUPAC nam es a
Nof.l1 the organic com pou nds whe re known by thei r com mo n nam e • but now .
try.
earlier d c 1 .
Union of Pure and Applied Che mis
i::.
0 und
s. IUPAC stan s ,or nter nat1.ona l
c0111P .
n by IUPAC for nam ing of org
anic com pou nds are ·.
idelines give . . e par ts
r11e gu org anic com pou nd con sist s of thre
O
rding to this sys tem , the. nam e of .
• ACC (3) Prefix
(l) Root wor d (2) Suf fix in.
t in lon ges t car bon cha
(!) Root wor d: It dep end s upo
n num ber of car bon ato ms pre sen
C1; Me th C5-Hex
C 2; Eth C7- Hep t
Ca- Oct
C9 -No n
C ; Pen t C10-Dec
5
ato m 0nd as
{2) suffix:
suff ix whi ch rep rese nt the nat ure of bon d in car bon -ca rbo n
The roo t wor d is foll owe d by
in it.
well as fun ctio nal gro up pre sen t
atio n Suf fix
co•m'poun~ V , '

• • ;!

. (Fu n~i on
one
(1) Alk ane
-C- C-
-C= C- ene
(2) Alk ene yne
-G C-
(3) Alk yne ol
-OH
(4) Alc oho l al
-CH O or
(5) Ald ehy de -C= O
I
H
one
(6) Ket one >C = O or- CO 0
0
II II
-C- OH -CO OH oic acid
/ (7) Car box ylic acid alko xy
R-0 -R'
(8) Eth er alk ane
X(F, Cl, Br, I) Hal o
(9) Hal ide
pos itio n in car bon cha in.
den ote s the sub stit uen t alky l or hal oge n gro up and its
(3) Prefix: It as 'Pa ren t o r ma in
ins: The lon ges t con tinu ous cha in of car bon ato m, kno wn
• Selection of carbon cha
chain' is rele a sed firs t
1 2 3 4
E.g.: (1) C- C- C- C
1 2 3
(2) C- C- C- C
I
C- C- C
4 5 6
it ion s a re ind icate d by
con s id e red to be s ubs tit uen ts o r s ide c hai ns a nd the ir pos
• The Bra n ch cha ins are
ch t he y are a tta che d.
num ber of car bon ato ms t o whi
1 2 3
E.g. C- C- C
I
CH
(2 -Met ~yl) 0

O rga nic Ch em ist ry ~ 46 9

 . f1
. of parent chain will be started from the side where side chain is at nearest .
• The coun t 1n 9 rom Position
12345 ,
5 4321
c-C- C-C -C C-C- C-C- C
I I
CH 3 CH3
2-Methyl (right) 4-Methyl (Wrong)
. . .
• In case, any functional group 1s present 1n chain, t hen num ben·ng is do ne from the side where~
Unct.iono[
group is nearest.
4 3 2 1
CH3- CH-C H-CH 3

dH3 6H
3-Methylbutan -2-ol (right)
1 2 3 4
CH3-CH- CH- CH3
I I
CH3 OH
2-Methylbutan-4-ol (wrong)
• In case, different types of side chains are attached to the chain,
they are named alphabetically.
1 2 3 4 5
CH3- CH-C H2-C H-CH 3
I l
Br Cl
2-Bromoe, 4-chloropentane
• The position(s) of alkyl group(s) or other·substituent are indica
ted by writing the position and name of the
alkyl group just before the name of parent hydrocarbon.

1 2 3
CH3- CH2- CH-C H3
I
CH2-CH3
4 5
3-Methylpentane
• Multiple alkyl groups are labelled with numerical prefixes
such as 'di' for two, 'tri' for three, 'tetra' for four.
etc.
If two alkyl groups are on the same carbon atom, the numeral
is repeated.
CH3
1 21 3 4 5
CH3- C-CH 2-CH 2-CH 3
I
CH3
2, 2-dimethylpentane

Example 6. Write the IUPAC name of the following compounds:

AnL 1 2 3
(1) CH3- CH2- CH-C H2-C H3
I
CH2-CH2-CH2-CH3 3-ethylheptane
4 5 6 7
CH3
1 2I 3
(2) CH3- C- CH3
2, 2-dimethylpropane
I
CH3
Cl
I
(3) CH 3-CH2 - C- CH2- 0H
4 3 2I 1 2-chloro-2-methyl
CH3
butan-1-ol
0

470 ~ Educ'art ICSE Chemistry Class X

 (4)

3 -Methylp
ent-2-ene
,AlkYl group
,,..Ar, alkyl group is ob tai ne d by .
ihe general for mu la of rerriov1n
111 an alkY l group, su ffi ,
alkyl g . g on
ix -yl ' is rou p is C H e ato m of h
pla ced . n 2n+ l· Ydrogen fro
m an alkane molecule. It is
in pla ce of on e represented by 'R'.
CnH2n + 2 ~ -C
(Alkane) .
nH 2n + 1 or R
(Alkyl)
CH4 ~ -C H3
Methane
Methyl
E,c
~ arn ole 7. W hich gr ou p is re
f,JII• Alkyl gro up spo ns1. ble for th e .
ph ysi cal properties of
organ.ic compound?
Functional gr ou p
It is defined as an ato
m or gro up
che . l .
m1ca pro pe rti es of the org of ato ms Joi
. .
an ic co mp ou nd s. ned in a specific ma nn er and is
E.g. : Al de hy de (- CHO) responsible for character
~eto ne
istic
, (- CO)
Example 8. W hic h gr ou p is
An•• Functional gro up rep on sib te fi . l prop
or ch em ica t· f
er ies O organic compo
unds?
Homologous se rie s
A
• hom• ologous ser ies
1n which the suc ces is a gro up of org an ic com
siv e co mp ou nd s differ bpo un ds having
. a similar t
CH t
Y
2 group . s rue ure an d s1m
· •
1lar chemical properties
Each me mb er of ser ies dif
molecular ma ss is ob ser ve fer fro m the pre cee din g on e b
d (B eca use mo lec ule dd" .
· rm as sof CyHa2 is1
ition of CH2 group . A reg
4). ular increase by 14 in
E.g. : Ho mo log ou s ser ies
of alk an es,
CH4, C2H 6 , C3H8 , etc.
Example 9. Write th e ge ne
ra l for mula of follow
ing:
(1) Alkane, (2) Alkene
, (3) Alkyl group, (4) All
eyne
Ans. (1) CnH2n + 2

W R IT IN G STRUCTUR
AL FORMULA FROM IU
• Write the nu mb er of ca
PAC NAME
rb on ato ms acc ord ing to
the roo t word.
• Number the ca rbo n ato
• According to th e suf fii ms fro m an y en d.
x an e, en e or yn e, th e
po sit ion of the bo nd is
• Attach the su bs tit ue nt spe cif ied in the pa ren t ch
or fun cti on al gro up at the ain.
• s0 t·....t
h:.i: y the fou r va len
cie s of ca rb on ato m by
me nti on ed car bo n ato m.
att ac hin
. g hy dro ge n ato ms
.
E.g. : 3-M eth ylp en tan e
step (1) C -C -C -C -C
1 2 3 4 5
Step (2) C -C -C -C -C

or ga ni c chemistry J(,I !_t I . Wf t

t::::9 .. , ,
 1 2 3 4 5
Step (3) & (4)
c-C- T- C- C
CH3
1 2 3 4 5
Step (5) cH 3- CH 2- CH- CH 2- CH3
I
CH3

I TOPIC 4 1
ALKANES
There are the compounds having general form h
ula CnH2n + 2· T e va lency of carbon is staisfied by singl b
only. They are also called as paraffins. e ond

Me thane
Methane is the simplest hydrocarbon, commonly calle M h
d as ors gas. Methane is a colourless, odourl
which insoluble in water. It contribute for gree ess gos
nhouse effect.
~am ple 10. Why Methane is known as Marsh
gas?
Ans. Met hane is known as Marsh gas because
it is found near the surface marshy areas.
Halogenatism of Methane and Ethane
Methane and ethane results in formation of Halo
alkanes or Halogenation.
(1) hv
CH4 + Cl2 ~ CH3Cl + HCl
hv
CH3Cl + Cl2 ~ CH2Cl2 + HCl
hv
CH2Cl2 + Cl2 ~ CHCl3 + HCl
hv
CHCl3 + Cl2 ~ CC4 + HCl
Or
hv
CH4 + 4Cl2 ~ CC'4 + 4HCl
(2) hv
C2H5 + 6Cl2 ~ C2Cl5 + 6HCl

Complete combustion of Methan·e and Eth

ane
Methane and Ethane burn in air with a bluish
non-soothy flame to form CO and water.
2
CH4 + 202 ~ CO2+ 2H20
2C2H5 + 702 ~ 4C02 + 6H20

ALKENES
Alkenes are the hydrocarbons having general
formula CnH2n- In alkenes a valency of carb
double bond . They are also known as olefins. on is satisfied by
The fi rst member of their series is ethene (ethy
lene) C2H4

~ Imp orta nt
-. Ethene is a comp ound which gives addit
ion reactions only.
• Reaction by Hydrogen (Hydrogenatio
· n): Hydrogen is added to ethen •
give et hone. . l t l11stto
e 1n presence of N1cke ca a ::,
Ni

JrI'.
472 tiJ ~art ICS E Chemis
Edu \-, try Class X
 nes
,Addition of Ha log ens (Ha
log ena t·
ion): Ethene reacts wit h
Haloge nes to give Ha loa lka
• CH CH 2 CL
2
II + Cl2 ~ I
CH2 CH 2Cl
1, 2-dichlore eth ane
CH2 CH 2- Br
11 + Br2 ~ I
CH 2 CH 2-B r
1, 2-d ichl ore eth ane ·
ora nge col our Wh to eth ene , the ora nge col our of bro mi ne
. e solution is CC4 has an en add ed dropwise
tio n of th l l .
9rorri1n due to the for ma e co our ess eth yle ne bromid
e.
diaPPears

Jf! impowith
~a nt . . .
fluorine is exp losi ve, hen ce
. not stab le.
com pou nd fi.orm ed is
action
.., ,,.e
0

~ Wh at hap
pen s wh en:
oxidised
i) Methane is com ple tel y
th .10d.me
0

) Ethene react w, h b .
(2 . rom ine
(3) Eth!Jne react wi t
Ans. (1) CH4 + 20 2 ~
CO2 + 2H 20
CH2 ~ 12 + CH2l
(2) Ill I
CH2 CH2l

CH CHBr1
(3) 111 + 2Br2 ~ I
CH CHBr2
ow n as Alefins?
Example 12 . Wh y Alk en e is kn
forming sub sta nc.
fin s bec aus e the se are oil-
Ans. Alkene is kno wn as ole

AL KY NE S
sat isfi ed by trip le bon d.
ura ted hyd roc arb ons in wh ich val enc y of car bon is
Alkynes are the un sat
s is CnH2n _ 2-
The general for mu la of Alk yne
is eth yn e (C 2H2.).
The first me mb er of the ir ser ies y.
giv es add itio n rea cti ons onl
Ethyne is a com pou nd wh ich
n (Hydrogenation):
• Reaction wit h Hydroge in pre sen ce of Nickel cat aly
st.
rea ct wit h Hy dro gen to for m atk ene and the n alk ane
Ethyne
. CH2 CH3
CH 2 /Ni ) I
Ill + H2 ~ II H

CH2 CH3
CH
(Halogenation):
• Reaction wit h Halogens
CHCL CHCL2
CH Cl2 ) I
Ill + Cl2 --- + II CHCl2
CH CHCL

! 1
'.;5Est Suggestions
i.,. Sn er and the diff
erence bet we en con den sed for mu la

th e videos sho win g iso me rism -ho w car bon ato ms rea
and stru ctu ral for mu la wit h the
rra nge themselves res ulti
help of exa mp les.
ng in for ma tion of isomers
l . 'bl e.
.

i.,. ee . all the bon ds pro per Y v1s1

h
Always wnte. d ow n the stru ctu ral for mu la of org ani c com pou nds wit
0

Orga ni c Ch e m is try l:1!:J 47 3

 TIVE Type Questions
es:
The unsatura~ed hydro.carbo n undergo
7
• (a) substitution ~ acti on
Multiple Choice Question [ 1 ma rk]
(b) Addition Reactio n
(Strictly fo r !CSESemeste r-II Exams) (c) oxidation React~on
.......
1. The general formula of alkene is ........ (d) Reduction Re~ct1on
(a) CnH 2n + 2 (b) C.,H 2n + 1 b Addition Reaction
1 1 • l b d
Ans. i i 'I double
(d) CnH 2n - 2 Expla nation: The tn~ e .onl coftnvert in
(c) C,,H 2n a er addi tion Of
and double convert in sing e
Ans. (c) CnH2n groups.
Explanation: The general fo rmula of
alken_e
on rs S. Alkanes are also known as:
is Ci,H 2n, In alkenes the vale ncy of carb (a) Olefins (b) Paraffins
satisfied by double bond only. (d) None of these
(c) Ester
ns and
2. The property of carbon to form chai Ans. (b) Paraffins
rings is called: relat ive[
(b) Polymerisation Explanation: These h~drocarbon~ _are
(a) Catenation cond 1t1ons and s
(d) Hydrogenati unreactive .under ordinary
(c) Cracking they are also known as Paraffins. o,
Ans. (a) Catenation
Explanation: The property of self-linki
ng of
9. Methane is also known as:
cova lent bonds in
atoms of an element through (a) Marsh gas (b) Olefins
nation.
order to form chains is known as cate (c) Esters (d) None of these
s differ
3. Two neighbours of homologus serie Ans. (a) Marsh gas
Marshy
by: Explanation: Methane also known as
r marshy area rs.
(a) CH (b) CH2 gas because it is found nea
(d) CH4
(c) CH3
10. In an orga I
nic compound, the group that
Ans. (b) CH2 is:
ns we maintains its identify in chemical reaction
Explanation: On adding CH 2 in alkyl chai
get next member of series. (a) Alkyl group
(b) Functional group
molecule
4. The number of C - H bonds in ethane (c) Both of thes e
is:
(b) 12 (d) None of thes e
(a) 6
(c) 4 (d) 2 Ans. (b) Functional grou p
ts the
Ans. (a) 6 Explanation: Functional group represen
Explanation: properties of an element.
H H 11. The organic compound having a triple carbon-
I I [ICSE 2020 )
H-C -C -H carbon covalent bond, is:
I I (a) C3H4
H H
(b) C3H 6
satisfied (c) C3H9
5. In aUc.enes the valency of carbon is
by: (d) C4H10
(b) Double Bond Ans. (a) C3H4
(a) Single Bond
which
(c) Triple Bond (d) Ionic Bond Explanation: Alkynes are hydrocarbons
Their
contain carbon-carbon triple bonds.
Ans. (c) Triple Bon d CnH
group general formula is 2 n-l·
Explanation: Carbocyclic compounds are 3 satisfies the formula while
the C H2 3 - 2 = C3H
of organic chemcial compounds in whic h all
k 4
s 0thers in the options do not.
atoms composing the ring are carbon atom
e.g. benzene.
~ \ ,.-. -~
6. Ring chain compounds are also calle
d: ' ,.,~~ .
:- "[.l:, V, s,
. ·,,,_ ,..,,
>4, '¼c "· ~ ' ..
(a) CarbocycUc (b) Inorganic f;-=tI
(d) None of these X/- Wh at Examiners say
(c) AUphalic ·~ Th ' most of th e
is .part was well attem pted by
Ans. (a) Carbocyclic candidates, but a few chose C3H5-

0
. 1- ire s: rh, >m idrv r:l::ic;c; y
 /J> caution
_,. Understand the differences in th
Explanation: As alkenes (CnH2n) u n<lerg~
a/kanes, alkenes and alkyn es. e genera/ fo ~~Ly
rrnula of addit ion react ion and never sub5titu
,on
JZ• Ahydrocarbon which is a greenho1.1 rea ction .
(a) Acet ylene se gas Is: 15. Aluminium powder la used in ther
mite
(b) Ethylene w•ld lng becauae:
(c) Ethane
(a) It la a strong reducing agen t.
(d) Meth ane
(b) It la a strong oxidising agen t.
Arts, (d) Meth ane [ICSE 2019 ]
(c) It Is corrosion resistant.
expla~ation:. Meth ane (CH 4) is a hydrocarbo
n (d) it ls a good conductor of heat .
that 1s a primary comp onen t of
.
Methane 1s a gree nhou se gas and itsnatural gas [ICSE 2014]
.· Ans. (a) It is a stron g redu cing agen t.
the atmo sphe re effects the earth 's t presence in
. emperature Explanation: Thermite process is the reduc
and climate system. tion
,'\ \, ' of metallic oxides with aluminium. Alum ini
Dot Met~~n~1>r,
,\.1.."'"'-.'' ,,,
um
~~: ~·:S·~r~.·
.· i is used beca use it is stron g reducing agen t and
' ,~~ ~·~~~~f
.: it reduces Fe 20 3.
. ,. ~" ,;~, ,, ?,
~ What Examiners s~y " . . • ,, ~;.:. ,, · Fe203 + 2A l~ 2Fe + Al203
., '+. .. "'.

16• .Identify the state men t that is incor

rect abou t
• Most candidates answered correctly, but allcanes:
some chose
Ethane over Methane.
(a) They are hydrocarbons.
11. If the mole cula r form ula of an orga
nic (b) There is a singl e cova lent bond betw een
comp ound is C10H1a it is:
(a) alke ne carbon and hydr ogen .
(b) alka ne (c) They can undergo both subs titut ion
as
(c) alky ne well as addition reactions.
(d) not a hydr ocar bon [ICSE 2017] (c) On comp lete comb ustio n they produce
Ans. (c) alkyn e
carbon di oxide and wate r [ICSE 2013 ]
Explanation: The mole cula r form ula of
alkyne Ans. (c) They can unde rgo both subs
is C10H1s• The gene ral form ula of alkyn tituti on as
e is well as addi tion react ions.
CnH2 n- 2
Explanation: As alkan es only unde
C10H2x 10 - 2 = C10H 1s rgo
subs tituti on reaction.
The gene ral form ula of alke ne is CnH n
2 17. The organic comp ound whic h
unde rgoe s
C10 H2 x 10 = C10H 20 substitution reaction is:
The gene ral form ula of alka ne is CnH2 n +2 (a) C2H2
C10 H2 x 10 + 2 = C10H 22
(b) C2H4
(c) C10H1a
(d)
C2H6 [lCSE 2018]
Ans. (d) C2H6
.,. Alkene or alkane was the occasional incor Explanation: When amm oniu m hydr
rect answer oxide
written by many candidates. is adde d to calcium nitra te, no reac tion
or
form ation of prec ipita te is seen . As a mmo nium
14. Identify the stat eme nt which does hydroxide \s a weak acid, it is very diffic
not
deacribe the property of alkenes:
(a} They are un1aturated hydrocarbons
for the m,ions to displace the NOs2 ions in
ult

calci um nitrate.
(b) They decolouriH bromine wate r
D orC2:H6
(c) They can u~dergo addition aa well
aa (Marking Scheme]
1ubl titut lon reac tion a.
(d) They undergo com bult lon with oxyg
en Jv] What Examiners say
forming carbon dioxide and water. • Man!) cand idates made random choice
s indicating
they did not associate the met that alkanes
[ICSE 2015) substitution reactions or did not apply the
show
Ans. (c) They can unde rgo addition as well general
as fo rmula to select the correc t alkane.
substitution reac tions
0

f'I!.
org anic Chemistry ~ 475
 ·on· Dimethyl ethe r is CH 30CH
f dimethyl ether is: Exp Lanat 1me• is Methoxy 3 and ·
Methane. ts 1

1s. T he /UPAC name o IUPAC na

(a) Ethoxy methane B or mathoxy meth ane
(b) Methoxy meth ane [Marking Sche
F\'\t)
(c) Methoxy etha ne
~ What Examiners say
(d) Ethoxy etha ne [ICSE 2018)
-. Many can di.dates were unsure of the correct n
Ans. (b) Methoxy Methane arne
and gave varied name s.

( SUBJECTIVE Type Que sti0 ns )

Fill in The Blanks [ 1 mark] 26. When an alka ne loos e a hydrogen
group is form ed.
19. The first organic compound discovered
is Ans. Alkyl (R)
Explanation:
Ans. Urea (NH2CONHv Alkane ~ Alkyl group + Hydrogen
Explanation: It was prepared by heati
ng CnH2n+2 ~ CnH2n + 1 + H
ammonium cyanate (NH2CHO) It is represented by R.
20. ............... is a necessary elem ent in every 27. The suffix used in nom encl atur e of
alkene is
organic compound.
···············.
Ans. Carbon Ans. One
Explanation: Carbon is an element essential 28. Carboxylic group is repre sente d by ...............
for .
every organic compound.
Ans. COOH
21. Carbon has the elem ent having .........
...... 29. Conversion of ethanol to ethene by the action
valency.
of concentrated sulphuric acid is an exam
Ans. Tetra ple
of_ __ (deh ydra tion/ dehy drog enat ion/
Explanation: Carbon has the atomic number
six. dehydrohalogenation)
There are four electrons in outermost shell and
it require only four electrons to complete the [ICSE 2019]
octe t Ans. Dehydration
22. ............... are the compounds made up
of
hydrogen and carbon only.
Ans. Hydrocarbon. [Marking Scheme]
Explanation: Hydrocarbons are the compound
s ~ Wha t Examiners say
in which valency of carbon is satisfied by -+ Several candidates were confused
hydrogen only. between
dehydration and dehydrogenation.
23. Organic compounds are generally insoluble 30. The comp ound form ed
in whe n ethe ne reacts
with Hydrogen is ............... . [ICSE 2017]
Ans. Wate r
(CH4, C2H 61 C3 H8)
Explanation: Water is polar compound while
organic compounds are non-polar in nature.
24. The Hydrocarbon containing only single bond
is called ............... . [Marking Scheme]
Ans. Alk.anes ~ Wha
XI- t Examiners say
Explanation: When all fo ur valencies of carbo
n -. Mo st of the candi dates answ ered correc
is satisfied by single bond only then it is called tly. A fe W
gave answers as CH or c Hs,
saturated hydroca rbon or alk.an e. 4 3
31• Conv
25. In homologus serie s ............... group is adde ersion of ethe ne t o et hane is an
d ~xadmple of ..............................
to the next member of series. (h ydration/
Y roge natio n). [ICSE 2016]
Ans. CH2
Ans. Hydrogenation
Explanation: A Hom ologus serie s is a grou
p
of organic comp ound s in which the successive hydr ogen ation
compound s differ by CH2 group .
[Marking Scheme]

476 f:::a
r°r1r
Edu c'ar t ICSE Che mis try Cl ass X
 ~ What Examiners say
°(I.,. candidates . got
confused b
etween I d
Explanation: CH 4 met hane is called saturated
hydrogenat'.on . and fa iled to u 1Y ration and hydrocarbon. It is three dimensional in shape
hydrogenation 1s addition of hydro ;derstand that and IL fo rrnu tetrabedron.
9 11
is addition of water. and hydration
C1H'1 Et hene is an lmsat urated hydrocarbon.
~". The compound formed whe n eth It s gonera l name is ethylene. It contains one
'" d' . anal react doublo-bond.
with so ,um ,s .............. (sodium h s
'd et anoote Urea NH2CONH 2 is fi rst organic compound
sodium ethox, e, sodium propa ,
noate). which was prepared in laborat ory by heating
ammonium cyanate.
[ICSE 2014]
sodium Ethoxide.
Aris, . NH4CNO ~ ~' NH2CONH2
Explanation:
Ammonium urea
2C2HsOH + 2Na ~ 2C2HsONa + H2i cyonate
(Sodium Ethoxide) CH3COOH is ethanoic acid (acetric acid). It is
organic compound containing the carbonyl
group (- COOH) is known as carboxilie acid.
Match the Follow~~~- - [ l mark]
I - - -- --:...:' CH3COOH is ethanoic acid (acetric acid). It is
33, Colum n (I) - - ; Column (II) organic compound containing the carbonyl
(a) Alkanes
-t - - -- -- - - - group (-COOH) is known as carboxilie acid.
(i) CnH2n
Alkyene is an unsaturated hydrocarbon. Its
(b) Alkenes (ii) CnH2n + 1
general formula is CnH 2n + 2.
(c) Alkynes (iii) CH 2
The simplest alkyene is C2 H2 acetylene (ethyne).
(d) Alkyl (iv) CnH2n + 2
(e) Homologous (v) CnH2n-2 True & False [ 1 mark]
Series I 35. Alkenes are the hydrocarbons having single
f,tis. (a)-Ov), (b)-0), (c)-(v), (d)-(ii), (e)-(iii) bond only.
General formula of alkanes is CnH 2n + 2. Ans. False
Explanation: Methane CH 4, Ethane C2H6, Explanation: In Alkenes, the valency is satisfied
propane C3H3, butane C4 H 10 etc. by double Bond.
General formula of dkenes is CnH 2n. 36. Hydrocarbons are the compounds formed by
Hydrogen and Carbon only.
For n =2 C2H4 Ethene
Ans. True
n=3 Propene
Explanation: Hydrocarbons are the organic
n=4 butene compound formed by carbon and hydrogen
General formula of alkynes is CnH2n _ 2- only.
For n=2 C2H 2 acelylene 37. The suffix used in nomenclature of alcohol
(ethyne) is ol.
n =3 propyne Ans. True
n = 4 C4 H6 butyne Explanation: Alcohols is the functional group
having suffix used ol.
General formula of alkyl is CnH2n + 1·
-H 38. Alkanes are also known as olefins.
CnH2n + 2 ~ CnH2n + 1
Ans. False
Alk.ane Alkyl Explanation: Alkanes are known as Paraffins
because they are relatively unreactive under
34. Column (f) Column (II) ordinary conditions.

(a) CH4 (i) Unstusated 39. Carbon has the tetra valence of four.
Hydrocarbon Ans. True
Explanation: Carbon has four electrons in
(b) CiH4 (ii) Carboxylic oxid
outermost shell. Hence it require four electrons
(c) NH2CONH 2 (iii) Saturated t o complete t he octet.
Hydrocarbon
, (d) CH3COOH (iv) Urea Name the following [ 1 mark ]
I was fi rst
Aris l (e) ~lk~ene_ _ l ~)_!:thene 40. Organic compound which
synthesized.
· (a)-(iii), (b) -(v), (c) -(iv), (d) -(iv), (e) -(i)
0

organic Chemistry T'I! 477

f:::S:J
 •
al sources of alkanes.
the first orga nic compound synthesized 52- Prine1P
Ans. Urea was . g ammonium cyanate . are majorly found near natural
in at by heat,n Ans. Alkanes 9as or
Pet roleum tanks.
NH 4 CN0 ~ NH2CONH2
53. A green house gas.
,41. A simples t Hydrocarbon. Methan e is a green house gas.
Ana.
Ans. Methane is t he first member of alkane series Compound reaponslble for ripening of fruit.
and regarded at simples t hydrocarbons 54.
Ethylene is used in ripening of fruit as it is Plant
Ans. O
42. compounds having same molecular formula hormone.
but dlff&rent structural formula .
ss. Name the saturat ed hydrocarbon COntQining
Ans. Compounds having some molecu lar formula two carbon atoms.
but different it structur al ones are regarded [ICSE 2019]
as isomers and this phenomenon is known as Ans. The saturat ed hydroca rbon containing tw0
carbon atoms is Ethane, C2He.
isomersism.
r.1,~;,..:.;,.' ·n-1~
c-. ct,1 a ,,.
43. The next higher membe r of propane. 1/ }t;//~)_'.J,/'-',
Ans. Propane has 3 carbon atoms. The next membe r ,.,.0 !
f:;r,.9;, :;,,J",,.L;:
~:,....' ,.,, ,
will have 4. Hence putting the value of 4 in
formula CnH 2n+2 we get C4H10 (Butane) g;J What Examiners say
• Most candidates answered correctly while som
44. The type of reactions alkenes undergo. , d
stated it as ethene or ethyne mstea of ethane. e
Ans. Alkenes are the compound in which value of • A few candidates gave the general name for the
carbon is satisfied by double bond. Hence it will homologous series instead of specific name.
give addition reaction and give compounds with
56. The organic compo und which when solidified,
single bond only. forms an ice like mass. [ICSE 2019]
-45. The type of reactions allcanes undergo. Ans. Acetic Acid
Ans. Alkanes satisfy three valency by single bond. r/,.,-,,..' • , ...,,~-

~ -~;tft~hoic a~i~ '0FCH3COOH

Hence give substitution reaction.
[Markin g Scheme]
46. The chemical name of the gas, which evolves
in marshy lands in form of Bubbles. g;J What Examiners say
Ans. Methane is a gas found in Marshy areas. Hence, • Almost all candidates answered correctly.
also known as Marsh gas. 57. Ethene undergoes hydrog enation reaction.
47. Name of the first membe r of alkene series.
[ICSE 2019]
Ans. Nome the first membe r in alkene series is ethene
CnH2n = CnH2 x 2
= C2H4
..a. The group which determine the physical [Markin g Schemel
properties.
Ans. Physical propert ies depends on structur e
fell What Examiners s~y
molecu lar mass etc. Hence it depends on alkyl • Several candidates wrote H is evolved in the
2
group. hydrogenation reaction of ethene. which was an
incorrect answer.
49. The group which determines the chemical
properties.
58. Reaction of ethano l and sodium . (ICSE 2018]
Ans. Functio nal group is responsible for the chemic al Ans. Hydrog en (H )
2
nature of compou nd.
Hy~ro9 ~n b~Hi
SO. The system of assignment of names to
organic compound.
~
• ' ~
Ans. Nomen clrature is a system to give names t o ~ What Examiners say
organ ic com pounds. There are t w o system :
~ Several candidates wrote ethane/ethene is evolved
(1) Tririal (2) IUPAC wi th the reaction of ethanol and sodium which was
51. Commo n name of ethano lc acid. an incorrec t answer.
Ans. Ethanoic acid is also known as acetic aci d or 59. An organic compo und contain ing -- cooH
vinegar having formula CH3COOH. functio nal group. - [!CSE 2017]
Ans. Carbox ylic Acid
0
JFI!
478 c::19 ~
Edu\...art ICSE Chem istry Class x
 qqrboxylic acid

[Marking S h Ans. Alkanes

~ What Examiners so c erne] 69. Preparation of ethane from sodium
,.. Some candidates wrot Y propionate. [ICSE 2014]
group. e carbonic acid Ans.
or carboxylic C2HsCOONa + NaOH ~ C2H
6
60• The catalyst used
in the
Sodium Cao
Ethane
ethyne to ethane. conversion of propionate
+Na2C03
Ans, Nickel [ICSE 2016] Sodium carbonate
70.
Nib,kel :' , ', Catalytic hydrogenation of ethyne.

A [ICSE 2014]
[Marking ,ScheMel ns. Presence of Nickel as
a catalyst and a
~ What Examiners say temperature of 200°c.
,.. Candidates selected v20 Explanation:
,=, .
s 0 r e instead of Nickel CH Ni
61. The type of reactions alk · 2 2 + H2 2000c > C2H4.
enes undergo. 71.
Sodium propionate is heated with soda Lime.
Arts. Addition reaction [ICSE 2016] [ICSE 2013]

Addi'ti¢:~,,R;cicirb~,;';"~t ', ·",

Chemical Equation:
' . ( /\~·ft;_'./ j~?~rig Sch,;,,.,] C2HsCOONa + NaOH ; ~~c > j c2 H6 +
wJ What Examiners sa~ '~ ,,,,
0
Ethane
.,. Errors committed were
(1) Substitution reactions Na2C0 3
(2) Hydrogenation reaction 72. A reaction in which hydrogen of an allcane is
(3) Halogenation reaction replaced by a halogen. [ICSE 2013]
Addition reactions were left out. Ans. Halogenation

62, This gas is also a saturated hydrocarbon. 73. T~e reaction in which carboxylic acid reacts
with alcohol in the presence of cone. H2S04 to
[ICSE 2015]
form a substance having a fruity smell
Ans. Ethane (C2Ha) gas is also a saturated
hydrocarbon. [ICSE 2020]
Ans. Esterification
63, Process by which ethane is obtained from
ethene. [ICSE 2015]
Ans. Hydrogenation (C2H4 + H2 Ni C2 H6) "' izi::J~~rldng SchemeJ

64.
300°c
A hydrocarbon which contributes towards the
'wJ. What Examiners say. .
greenhouse effect. [ICSE 2015] -. Majority of the candidates gave correct answers.
-. A few mentioned it as 'ester' or neutralization
Ans. Methane (CH 4) reaction.
&S. Distinctive reaction that takes place when
ethanol is treated with acetic acid. [ICSE 2015] Give the Balanced Chemical Equation
Ans. Esterification [ 1 mark]
66, The property of elements by virtue of which 74. Preparation of methane from iodomethane.
atoms of the element can Link to each other [ICSE 2017]
in the form of a Long chain or ring structure. Zn+ dil. HCL
[ICSE 2015] Ans. CH 31+ 2[H] CH4 + HI
Ans. Catenation
67 • Reaction
when an alkyl haUde is treated with
3CuO + 2NHr-4'3C~,_.. §Hl f~:Ni"'
"·
i •,~·' ,.
alcohoUc potassium hydroxide. [ICSE 2015] [Mark.Ing
'
Sch~m~l
. ,
,,

Ans. Dehydrohalogenation
68. ~ What Examiners say
0 -. Some candidates wrote N02 instead of N2 as the
II product while in some cases the equation was not
Hydrocarbons containing a - C - functional balanced correctly.
group. [ICSE 2014] 0

Jr.I!_ 479
organic Chemistry ~
 Cao
. of H so 4 as an acid when It C HsCOONa + NaOH ~ C2Ha + N
75. The behavior ~ [ICSE 2017]
Ans. (A) 2 . 02CQ
reacts with Magnesiu m. (B) C·HsBr
2
+ KOH - 4 C2H4 + KBr +HO 3
2
Ans. Mg + H2S04 ~ MgS0 4 + H?i (alcoholic)
Mg + H2S04 ---+ MgS04 + H2 (A) C2HsCOONa + NaOH C2Ha + Na2C03
[Marking Schema] (B) C2HsBr + KOH --t KBr + H20 + C2H4

~ What Examiners say [Marking Sch~

1oot Almost all the candidates w rote this
equationcorrectly. A few candidates wrote H20
wJ What Examiners say
_. (A) Most of the candidates answered tri,-,
insteadof H2·
part correctly.
76. Preparati on of ethanol from ethyl Chloride. _. (B) In several cases the chemical reacti
was written using aqueous KOH instead ~;
[ICSE 2016)
with alcoholic KOH.
Ans. B C2H5Cl + KOH(oq) -----1 C2HsOH + HCl
80. Write a balanced chemical equation for eacti
C2H5Cl + KOH(aq) ~ C2H50H + KCl of the following:
[Marking Scheme] (A) Burning of ethane in plentiful supply of
~ What Examiners say air.

"- Reagent required was incorrectly written as alcoholic

(B) Action of water on Calcium carbide.
KOH/ NaOH or simply water. Some candidates wrote (C) Heating of Ethanol at 170°C in the
the wrong fo rmula for ethyl chloride as well as for presence of cone. Sulphuric acid.
ethyl alcohol
[ICSE 2016]
77. Chlorine gas is reacted with ethene. Ans. (A) 2C2H6 + 702 ~ 4C02 + 6H 20
[ICSE 2019) (B) CaC 2 + 2H 20 ~ Ca(OHh + C2H
2
Ans. H2C = CH2 + Cl2 ~ H2C - CH2 t
I I

}il
Calcium Carbide + water Acetylene
Cl Cl cone. H2S04

HrCH,+m-.H,C-r (C) C2HsOH ---~C 2H4 + H2

Ethanol
110°c
Ethylene
81. Give balanced chemica l equation s for the
[Marking Scl,~~ ~1~ following conversions:
(A) Ethanoic acid to ethyl ethanoate.
~ What Examiners say (8) Calcium carbide to ethyne
..,. Some candidates wrote the product as C H Cl (C) Sodium ethanoat e to methane.
2 2 2
instead of C2 H4 Cl2 in the chemical equation. pCSE2015]
78. Producing ethane from bromoethane using Ans. (A) Ethanoic acid to Ethyl Ethanoate
Zn/Cu couple in alcohol [ICSE 2020) con.H2SO 4
Ans. C2HsBr + 2[H] Zn/Cu C2H6 + HBr
Couple in alcohol CH 3 COOC2Hs + H:0
(Ester)
C2HsBr + 2[H] ___
zn_/c_u_ ___.
Couple in alcohol
(8) Calcium Carbide to Ethyne.
C2H6 + HBr.. ,. CaC2 + 2H 20 ~ Ca(OHh + C2 H2
[Marking Scheme] (C) Sodium Ehanoate to Meth ane
f.7-1. What Examine rs say CH 3COONa + NaOH ~ Na2 C0 3 + CH➔
• Many candidate1, were confused with the condition 82. Preparation of ethyne from ethylene
given - Zn/Cu couple in al.coho/. dibromide. [ICSE 2014]
79. Give a balanced chemical equation for ea ch of Ans. Hot Ethanoic solution of Potassium hyd roxide
the following : Explanation:
(A) Preparation of ethane from Sodium Br Br
propionate I I
(B) Action of alcoholic KOH on bromoethane. H - C - C - H + 2KOH -----1 H - C== C- H
I I Ethyne
[ICSE 20 17]
H H
0
r r1r
480 c:0 ~
Edu~ ort ICSE Chemistry Class X
 dium hydroxide ine
eth an ol ferred _to so ethane
becaus
preparation of Ans. Soda lim e is pre
91, ,rionochloro eth an e an d aq . sod' from
•um hydroxide. the labora tory pre pa~a
t,on of m d is
l1quescen_t a~ eli ue
a drying
scent. I
[Iese 20 141 soda lim e is no t dem hydroxide ,s d q .
agent wh ereas sodiu
C2HsCl + NaOH ~
C2HsOH + NaCl . · uescent or .1 • '
. no.t d e.11q
. e ,s
do es
ftflS• Ethanol Since so da
ack
lim
gla ss 6r sodium hydrox ,'ae Of~f ',
no t att · · ' nt
b
uations for the Iao ~~~ Ca O is a drying ag e './ /
Give balanced eq h
f t e following 0 ~ • de lique sce nt or
~ preparati.ons o gan,c Cao absorbs moisture
.
compounds: {Marking Sc:nemf!l
hydrocarbon from
(A) A saturated
iodomethane.
an
~ W ha t Examinersntisa y
oned that soda lime ac
ts as a
hydrocarbon from -. Most candidates me
(8) An unsaturated
alcohol catalyst. .
gave correct reasoning
hydrocarbon from -. Very few candidates
(C) An unsaturated
ns [ 1 mark J
calcium carbide. Analytical Questio of:
ethyl bromide. xt higher Homologus
(D) An alcohol from Give the formula of ne
[ICSE 2013J
91 . Methanol
Zn/HCl CH4 + HI
Ans, (A) CH3 I + 2H Ans. Ethonol
Methane
lodo 92 . Etharic
methane Ans. Propene
93 . Ethane
Ethene
Ethanol (cone.) Ans. Propene
Ca(OH)i + C2H2
(C) CaC2 + 2H2O ~ 94 . Ethyne
Calcium Ethyne
Ans. Propyne
Carbide 95 . Propyl
+ KOH(aq) ~ C2HsOH + KBr
(D) C2Hs8r Ans. Butyl
Ethanol
Ethyl
96 . Methanoic acid
Bromide
Ans. Ethanoic acid
[ 1 m ar k] 97. Propane
Explain B ri ef ly
85. Catenation Ans. Butane
atoms
self-linking of carbon 98 . Butene
Ans. The property of g straight,
to form lon
through covalent bond ati on . Ans. Pentene
is called caten
branched or ring chain
99 . Pentane
86. Homologus series in which Ans. Hexane
Ans. Aseries of comp
ounds of same family • Methanol
e CH 2 unit
each member differ
from next by on 10 0
and 14 molecular mass. Ans. Ethanal
[ 1 m ar k]
17• Hydrocarbons
ina tion of ca rbon W ri te IUPAC N am e
d by comb
Ans. Co mpound forme !0 1. cH 3 _ cH 20H
and Hy dro ge n on ly.
Ans. Ethonol
88 na l gr ou p
• Functio rties of
ible for the, prope 102. CH3COOH
Ans. A group respons
comp ound . Ans. Ethanoic acid
89• Isomerism
CH 2- CHO
g sa m e mo lec ula r form but 103. CH 3
Al1s. ~ompounds havin at is known as isome
rs Ans. Propanal
different structural form isome rism.
is known as CH2 - CH2
and this phennomenon 10 4.
ide In I I
ed to sodium hydrox
9o. Soda Ume is preferrar e. Cl Cl
th e laboratory prep ation of methan
[ICSE 20201 Ans.
1.2 -dichloroethane
0

Organic Chemistr
y ~ 481
 H 0
10s. CH3 - CH = CH - CH3 I II
Ans. but 2-ene (B)H -C-C -H
CH3 I
H
I
106. cH3 -CH -CH2 -CH -CH3 Ans. (A) The IUPAC name of the cornpounct .
I Propyne. IS

CH3 (8) The IUPAC name of the cornpounct

Ans. 2, 4-dim ethyl hexane Ethanol. is

107. CH3 _ CH 2 - CH - CH = :H - CH3

I
CH3
Ans. 4-methylhex-2 ene
CH3 CH3 wJ What Examiners say .
I I _,. (A) Most candidates attempted this part Well
108. CH2 - CH - CH2 However, some were confused between •yne·
I and "ene~
CH 2 - CH2 - CH2 _,. (B) In writing /UPAC name of the organic compound
Ans. 3-methylheptane many candidates wrote ethanol (alcohol) which
was incorrect.
CH3
114. Give the IUPAC name for each of the following:
I
109. CH 3 -C= C-C H (A) H-C = 0
I
I H
CH3
Ans. 4-methylpent 2-yne H H H
I I I
110. CH3 - CH - CH2 - CH2 - CH3 (B) H-C -C-C -OH
I I I I
OH H H 1-4
Ans. Pentane-2-ol
H H
111. Acetaldehyde I
(C) H3C-C = C -CH
I
[ICSE 2020] 3 [ICSE 2018]
Ans. Ethanol
• / , ,, ,'/'/'',, ,·,;;.,•.,:,,;f /;}:f;/.
Ans. (A) Methanol
.,...
ethanol /.l~~h9~0~/;etM~;J-"iq (B) Propanol
, ,.:· ~t'.;{t\i}\~-~f~~:,,,, (C) But-2-ene.
~ What Examiners say
..,. Some candidates wrote the /UPAC name as methanol f ~ A{M~thanal or methan-1-al
instead of ethanaL (; ,{B}'lPropanol or Propane - 1- OL
'. (C) 2Butene .or but - 2 - ene
112. Acetylene
Ans. Ethyne.
',<:.,. '. •/~:. •\, [Marking Scheme]

ethyne / 1 ethyne / eth- 1-yne wJ What Examiners say

~ Some candidates wrote trivial or commo n names.
[Marking Scheme] (1) methanoneinstead of methanol.
~ What Examiners say
(2) Name ended by 'al' instead of 'ol' while some
incorrectly wrote prop-l-ol.
..,. Most candidates attempted well but some _
were (3) 1.2-dimethlyethene instead of 2-butene or but- 2
confused between 'ene' and 'yne'. ene. Some wrote simply butane or butan-2-ene.
113. Give the IUPAC name of the following organ
ic
compounds: [ICSE 2019] Writ e the Structural Formula
H [ 1 mark ]
I 115. Vinegar
(A) H- C-C =C-H
I Ans. CH 3 - COOH
H 116. Marsh gas
Ans. CH 4

482 ~ Edu ~art ICSE Che mist ry Class X

 cetone Metha nol
l· ~H'.l _ c,, - CH3 H
A,,s, o I
H- C-0 - H
panoic acid I
,j9• pro CH 2 - COOH H
~ CH3- [Marking Schem e)
At1S•
_dimeth ylbuta ne
23
jjf• ' _ CH - CH - CH3 fa>7] What Examiners sa y
Af1S• CH3 I I -. Most candidates drew the structural formul a
c H3 CH3
correctly.
ethan e -. A few candidates drew the conden sed formul a
1 2-dichlo ro instead.
12D, ' - CH 2
Aris. TH2 I 1 27. Acetic acid. [ICSE 2019}
Cl CL Ans. The struct ural formu la of Acetic acid is:
H 0
j2S.. Ethanol I II
CH3CHO H-C -C-O H
Ari S·
I
, Formaldehyde H
122
t,.ris, HCHQ
The ; tructu ral formu la of Acetic acid is:
123, But 2- yne H 0
Ans. cH 3 - C=C- CH3 I II
H-C -C-O H
124. Propyne :c / •/ . I
Ans. cH 3 - C = CH H
[Marking Schem eJ
125, 2, 2 dimethyl penta ne ,·

Ans. 1, 2, 2 dimeth yl penta ne g7] What Examiners say

H H H CH3H _,. Several candidates wrote the structu ral form ula
I I of acetic acid correctly. However, som e candid ates
I I I wrote the conden sed formula ofCH3 and COOH.
H-C -C-C -C- C-H
I I I I I 128. Write the struct ural form ula of the two
H H H CH3 H isome rs of butan e. [ICSE 2018]
Ans. 2 Isome rs of Butan e
H H H H
I I I I
H-C -C-C -C-H
I I I I
H H H H
Butane
H H H
I I I
H-c- C- c-H
£11
'fl- What Exam iners say
I I I
a H I H
"- Some candida tes wrote the conde nsed formul H- C-H
._ instead of the structural formul a.
I
~vlany candidates did not unders tand the difference H
.,. Setween straight and branch ed chain. 2, M ethyl Propan e
t:;e showed carbon skeleto n but m issed showin g
1 complete structural form ula. 2 Isom ers of Butan e
26
11.n ' Methanol [ICSE 2020] H H H H
s. Methanol I I I I
H- C- C- C- C- H
H I I I I
I H H H H
H- C- 0 - H Butane
I
H 0

Orga nic Che mist ry 6.. 483

 H H H CnH2n + 2 = 86
I I I (n x 12) + (2n + 2) x 1 = 86
H~ c- C- c- H 14n + 2 = 84
I I I 14n = 84
H I H
H- C- H n =6
I Molecula r Formula CsH14
H Isomers:
2, Methyl Propane
(1) CH3 - CH2 - CH2 - CH2 - CH
[Marking Scheme] 2 -- CH,
n-hexane ,
wJ What Examiners say 5 4 3 2 1
._. Many candidates did not understand the (2) CH 3 - CH2 - CH2 - CH - CH
difference 3
between straight and branched chains clearl
y. Some I
showed the Carbon skeleton and missed show CH 3
ing the
complete structural formula. 2-methylpentane
1 2 3 4 5
Short Answer-I Type Questions (3) CH3 - CH2 - CH - CH2 - CH
3
[ 2 mar k] I
129 . Name the following organic compounds: CH3
3-methylpentane
(A) The compound with 3 carbon atom
s
functional group is a carboxyl. CH3
(8) The first homologue whose gene I
ral (4) CH3 - CH2 - CH - CH3
formula is CnH2n•
4 3 2 1
(C) The compound that reacts with
acetic I
acid to form ethyl ethanoate.
CH 3
(D) The compound formed by com 2, 2-dimethylbutane
plete
chlorination of ethyne. [ICSE 2019] 4 3 2 1
Ans. (A) Propanoic Acid
(5) CH 3-C H-C H-C H3
(8) Ethene
I I
(C) Ethanol CH3 CH3
(D) 1, 1, 2, 2. tetrachloro ethane 2, 3-dimethyl butane

:li1!fiii~l!i~;~,
131 . What do you mean by chain isomerism?
Explain with example.
Ans. Two or more compounds which have
similar
molecular formula but different arrangement
of
/'
· .,:·',:/\;;.· ., /,.·1[Ma~k:1pg SchemeL
, ,, , , : , ,
carbon atoms in straight or branched chains are
., ,/, ,· •• , ., ,! ·, , , ' , ~ ! ' _,, i

~ Wha t Examiners say referred to as chain isomer and the phenomnon

.,. (A) Some candidates incorrectly drew
is known as chain isomerism.
the structural
formula when the name of the organ E.g. CsH12
ic
compound was asked. • CH3 - CH2 - CH 2 - CH2 - CH3
.,. (B) Several candidates gave incorrect
answers like, n-pentane
alkene, ethyne or acetylene.
..,. (q For the compound that reacts with 4 3 2 1
acetic acid
to form ethyl ethanoate, reactants listed CH 3-C H2- CH -CH 3
by
many candidates were incorrect.
.,. (D) Most candidates answered this I
subpart CH 3
correctly. However, some candidates wrote
incorrect numb ering of the C atom s having 2-methylbutane
the
chlorine atom s. CH 3
130 . A hydrocarbon having molecular mass I
86 is CH 3- CH - CH
given to you. Calculate the molecular formula 3
3 2 1
of compound and write the possible isomers I
ofit. CH 3
Ans. Molecular mass = 86 2, 2-dimethylpropane

484 "i:£, Edu Cart ICSE Chemis try Cla ss X

 ~
I
,.,rite a. short ..
note on p0s1t1on .
,,,,, v, b . . isomeriun, .
j,,. r:vplain 1t Y g1v1ng suitable example
.,,. .
sitional ,somers are con st·1tutio ·l . CHCL3 + CL 2 ~ CCL4 + HCl
Po
An 6• that have the same carbon skel na isomers or
functional group but differ fr eton and same CH4 + 4Cl2 ~ CCL 4 + 4HCL
location of their functional groou;. each other in
(B) 6Hs + 6Cl2 ~ 6HCl + C2Cle
E.g. CsH10
5 4 3 2 1 (C) CH4 + 20 2 ~ CO 2 + 2H 2 0
• CH3 - CH2 - CH 2 - CH = CH
2 (D) (1) Hydrogenation of alkenes:
pent-1-ene
CH2 Ni CH3
5 4 3 2 l
11 + H2 2OO°c I
• CH3 - CH2 - CH= CH_ CH 3 CH2 CH 3
pent-2-ene (2) Sydrogenation of alkynes:
CH Ni CH3
3, Write ·down the suffix &: pref.ix used fior
13 fo llowing fu nct·1ona l groups. Ill + 2H2 2OO0c I
CH CH3
(A) Alcohol (B) Ketone (C) Aldeh dl
(D) Carboxylic acid y
(E) (1) Halogenation of alkenes:
Functional - _Functional Suffix CH2 CH2Cl
Ans Prefix
group group Ii + Cl2 ---+ j
CH2 CH 2Cl
represen-
tion (2) Halogenation of Alkynes
CH CHCl2
(A) Alcohol -OH - of hydrory Ill + Cl2 ---+ I
0 CH CHCl2
II
(8) Ketone -C- - coe Keto/oxo 136. (A) Draw the structure of ethane.
0 (B) The reaction between ethane &: chlorine
II forms only one product. Name type of
(C) Aldehyde -C-H - al aldo reaction .
0 Ans. (A) H H
II I I
(D) Carborytic -C-O H - aic - C=C
I acid acid I I
H H
134. Explain the term alkyl group by giving suitable (B) Substitution
examples. 137. Which of the following is hydrocarbon?
Ans. An alkyl substitu ent is an alkane missing one C2Hs, C2HsOH, CH 3COOH
. hydrogen. The general formula of alkyl group is
Ans. C2Hs because it is made up of only carbon and
CnH2n+l· It is represented by 'R'.
hydrogen atoms linked togther by coualent
Alkane - H ---+ Alkyl group bonds.
CnH2n+2 - H---+ CnH2n+l 138. The molecules of alk.ene family are
or represented by general formula C,,H 2n.
'R' Answer the following.
US. What happens when: (A) What do n and 2n signify?
CA) Methane react with chlorine (B) What is name of alkene when n = 4?
(B) Ethane react with chlorine (C) What is the molecular formula of alkene
(C) Combustion of methan e takes place if there are six H-atoms in it.
(D) Hydrogenation of alkenes &: alkynes is
Ans. (A) n indicates number of carbon atoms and 2n
done indicate number of Hydrogen atom.
(E) Halogenation of alkenes &: alkynes is
(B) Butene (C 4 H8)
A. carried out
ns. (A) CH4 + Cl ~ hv CH Cl + HCl (C) C3Ha
2 3
139. Why hydrocarbons are excellent fuels?
CH3Cl + Cl2 ~ CH 2Cl2 + HCl Ans. Hydrocarbons are excellent fuels because they
ignite easily at low temperature and liberate
CH2Cl2 + Cl2 ~ CHCl3 + HCl
0

. ffI! 485
f::m
Organic Chemistry
 the acid Z, givhes a co.mp?und y Which ha
large amount of heat without producing harmful fruity smell T e reaction 1s: s0
product. z
c2H50H + X - Y+H 20
140. What is the special feature of the structure of
(A) Identify Y and Z.
ethyne? [ICSE 2019]
Ans. The special feature of the structure of ethyne is
(B) Write t he structural formula of x.
the presence of triple covalent bond. The shape (C) Name the above reaction. [ICSE
201
is linear due to sp hybridization in ca rbon atoms (A) y is Ethyl ethanoate (CH3COOC2Hs) SJ
Ans.
Triple bond between 2 carbon atoms / H - C z is concentrated Sulphuric Acid (H 2so4)
1.eC - H H2 SO4
cH 3COOH + C2Hs OH
(Marking Sch•m•J
CH3COO~ Hs + H o
2
~ What Examiners say Ethyl ethanoate

• Some candidates mentioned the presence of a linear (B) H 0

planar st ructure or three covalent bonds rather than I II
presence of t riple covalent bond. H-C-C-OH
• Some gave incorrect answers such as, unsaturated I
compound or, undergoes addition reaction and so on. H
(C) Esterification
141. Write a balanced chemical equation for the ,(\-'\ '*\,\>- ""'1¾.\ "' ~'"-'<'. ,' ' _ -·_ ', ·' ' ' -· ,.
preparation of. i:~~l~~:it ,§t,hyt ac~t~te / Ethyl ethanoate /
(A) Ethene from bromoethane. . ··" \ °CF-l3COOC2Hs ·
(B) Ethyne using calcium carbide.
;:,·::•,:·_,z\ C~ncentrated H2S04
~,,,, ·H . 0
(C) Methane from sodium acetate.[ICSE 2019)
Ans. (A) C2Hs8r + KOH~ C2H4 + KBr + H20
< I II ·
:::.j a) :H7""C-C-OH
Bromethane Ethene ~~<:(~):~ste~fication '
(B) CaC2 + 2H20 ~ Ca(OH)2 + C2H2 , , \:i}~:l::, ~· ·· .,'." , , [Marking Scheme]
Calcium acetylene
Carbide )v] What Examiners say
(C) CH3COONa + NaOH ~ CH 4 + Na 2C03 .,. (A) Many candidates identified compound Y
Sodium acetate Methane as C2HsCOOCH3 while some identified it
as ester. A few candidates did not mention
the strength of the acid.
.,. (8) Some candidates drew an incorrect
structure of compound X
.,. (C) Majority of candidates named the reaction
Calcium acetylene correctly. However, a few called it catalysis
Carbide which was not correct
(C) CH3COONa + NaOH ~ CH 4 + Na 2 CO 3 143. Give the structural formulae of each of the
Sodium acetate Methane following:
[Marking Scheme] (A) 2-methyl propane
(B) Ethanoic acid
wJ What Examiners say (C) Butan-2-ol [ICSE 2016]

- (o) In writing a balanced chemical equation for the

Ans. (A) 2, Methyl Propane
preparation of Ethene from bromoethane, H H H
the formula for bromoethane was written as I I I
C2H,J3r in place of C2H58r by some candidates. H-C-C-C-H

~ I ~
Several candidates used chloroethane instead of
bromoerhane.
,. (b) In writing a balanced chemical equation fo r the
H- C - H
preparation of Ethyne using calcium carbide,
some candidates wrote the product as CaO I
H
insr.ead of Ca (OHh
(B) Etha noic Acid
• (c) The formula of sodium acetate was writt en
incorrectly by some candidates. H
I
142. A compound X (having vinegar like smell) H- C - C-OH
when treated with ethanol in the presence of I II
H 0
0
rrn
486 (:::fliJ ~
Edu ~ art ICSE Chemistry Class X
 (B) Bromine whi ch is brow n
in colo ur, its
colo ur fade s as Eth ylen e Bro mid e
form ed
is colourle ss.

(A) A~ 1H2 Br
CCl 4 CH Br
2
H -C =C - H ./
I I
_H H .. , . .
.. · ·. .. , E~hylene.. {.; . .;:: : .
.
. (B) Bror,nine solution/is,d ecolo:u-rised
':
L, ,•, . ,c ~'.;'<;,:. .::/,.'\/IL.,;,·,\'~·;
biI , .• .~_;;;;,;:,;;-;\;;;:;;, t,:J ~.~ !-'Y~g:•~cheFM)
. .......
1
~ Wh at Examiners say
$ ./ • , /"

..,. (A) The moleculer formula

was given instead
of structural formula, i.e. C H
2 4
,'-,' ~ Or incorrect formula i.e. CH =
. ',"' ' ,: ·' CH 2 instead
(C) · . But an 2.;oL· ·, of H2C = CH2 or occasion2ally
"' ~ ~ '' -, .' "
ethane was
'
the incorrect answer.
... <'>>fl ., ..tk:.·
'\ '..

..,. (B) Most candidates answered

,< , .. I> .J,.. I this part welL
' rt :.~ ~·c .• ~ " 145 . Using their structural formulae
identify the
··· · · · · l ·, 'I ·.·'"I fun
ctio nal gro!Jp by circling the m:
... '~ ~ ·..-~:.}9;~i~ (A) Dimethyl ether
(B) Propanone.
~ ,~ -~< ~ :~ ~;~-\~ ) V Ans. (A) Dim ethy l Eth er [ICSE 201 5}
wJ What Examiners say H H
"- (A) Som e of the erro rs
mad e by candidates
I I
was givin g the con den sed
H- C- 0- C- H
form ula for I
met hyl (CH:J) grou p or all I
C not wer e sati sfie d as only
the valences of H H
the skeletal (B) Pro pan one
chain with the sub stitu ent was
draw n.
(B) Either the func tion al grou
p was confused H O H
with the alde hyd ic grou p I II I
OR The con den sed form - COO
H was written,
H- C- C- C- H
whic h was not acce ptab le. I I
(C) Errors mad e wer e eith er H H
(1) 3 carb on atom s inst ead of 4 146 . Give the structural formulae for
Or (2) - OH grou p atta che d to C the following:
num bere d 1 (A) An isomer of n-butane.
Or (3) Dou ble bon d betw een C
and H
of- OH grou ps. (B) 2-propanol.
(C) Diethyl ether.
144. Equation for the rea ctio n wh en compou [ICSE 201 3]
nd A is Ans. (A) Isom er of n but ane
bubbled thro ugh bro min e diss
olved in carbon
tetrachloride is as foll ow: H H H
I I I
Br:JCC4 H- C- C- C- H
~ ~
A ---➔
CH2Br
\
I H- C - H
CH2Br I
(A) Dra w the stru ctu re of A. H 2, Met hyle Pro pan e.
(8) Stat.e you r observation during this H H H
reaction. [ICSE 201 6) I I I
Br CH 2 Br (B) H - C - C - C - H
Ans. I
(A) A- -2+ 1 H OHI I
H 2-P rop ano l
CC l4 CH Br
2
H- C= C- H H H H H
I I l - Cl -
(C) H- C
o- 6- 6-
I
H
H H ~ 0~ ~ ~ H DiEthyl Eth er
Eth yle ne
0

o raa nic ch em ist ry

rrrr
 H H H H
I I I I
H- C- C- C- C- H
for the following:
.. I I I I
ot undergo add1t1on H I H H
147• Ghte reasons
Methane doe s n H- C- H
(A) . but ethene does. I
reactions, ne. H
h e is more reactive than etha
[ICSE 2012]
(8) Et ~n
2, 2-Dimet hyl propone
H
satu rate d
(A) Methane is an example of I
Ans. hydrocarbon and Ethene is an exa
mple H- C- H
ition H I H
of unsaturated hydrocarbon and Add I I I
tic of unsat urat ed
Reaction is a characteris H- C- C- C- H
hydrocarbo n which contain =
or == I I I
ition H I H
Bond and hen ce Ethene shows Add H- C- H
Reaction.
I
H '
bond
(B) In Ethyene due to presence of t riple
and so it · . [Ma rkin g Scheme]
electron density is very high
is a
is more reactive than Ethane which
saturated hydrocarbo n and hence less fell Wh at Examiners say
isomer correctly but
reactive. • Most candidates drew the first
could not draw the othe r two isom ers.
ns
Short Answer-II Type Questio
isom ers.
• Som e candidates drew only two
n correctly.
[ 3 mark] • Branched structures were not draw
the count of carbon
pentane. • Som e misse~ out H atom s or
148. Draw the structures of isomers of atoms wen t mcorrect.
[ICSE 2020] and the difference
• Many candidates did not underst
chai n.
betw een straight and bran ched
Ans. Pentane paragraph
H H H H H 149 . Copy and com plet e the foll owi ng
I I I I I using the options given in brac
kets:
H- C- C- C- C- C- H es of (A) ..........._
I I I I I Allcenes are a hom olo gou s seri
H H H H H hydrocarbons
(saturated I uns atu rate d)
era l formula
2 Methyle butane characterised by the gen
H H H H . (C,,H2n+2'C,,H2J, Allcenes undergo
(8) ..............
I I I I utio n) reactions
H- C- C- C- C- H (C) ............... (ad diti on/ sub stit
I I I I and also undergo (D) ....._.......
. (hydrogenation
H I H H
H- C- H I dehydro-genation) to form allcanes.
I [ICSE 2020]
H
Ans. (A) Unsaturated
2, 2-Dimethyl propone
H (B) CnH2n
I (C) Addition
H- C- H
H I H (D) Hydrogenation.
I I I
H- C- C- C- H (A) Unsaturated
I I I
H I H (8) CnH2n
H- C- H
I (C) Addition
H
(D) Hydrogenation
Pentone [Ma rkin ~. Scheme]
H H H H H
I I I I I
H- C- C - C- C- C- H ,97l What Exarn1ne
1oo,.
· rs say
I I I I I Most of the can dida. .
H H H H H correctly. tes answered this question
2 Methyle butane A few got con fuse d.
m the following fill in the blanks
1oo,.
and wrote:
{B)CnH2n+2 {CJ subs . .
titut,on-[DJ dehydrogenation.
0
JrJr
488 ca Ed uC art ICSE Ch em istr y Cl ass X
 -plete the follow.ing table whi'ch re ates to l (C) Propa noic acid
0 Co,,.
jS • the homol ogous series of hydro carbo ns: H H 0
I I II
!A~ . Chara cte- IUPAC name H- c - c - c - o - H
,ofth, r1$tlc bond of the first I I
~~9- type Member of H H
.,ries · the series
~-.:.. (A) 2, 3 - dimet hyl Butan e.
(A) ............... (B) ............... (C) ·······........ H H H H
~ -+:_. .:_--- --t-- --- -
(D) ............... (E) ............... (F) ...............
I I I I
H-C -C-C -C -H
[ICSE 2018) I I I I
H CH3 H H
(B) Diethyl Ether
H H H H
I I I I
H-C ~C- 0-C -C- H
CnH2n- 2 (A) Alkyne (B) Triple (C) Ethyne I I I I
bond C=C H H H H'
I

'CnH2n +2 (D) Alkanes (E) Simple (F) Metha ne / (C) Propa ~oic acid
/ --__ .L-- - - ~b_o_n_d_ _ ___,___ _ _ _...J H H 0
~ -~" ., .., ·,-' -I I II
~, \·", . "
(A) Alkyne
~~--\ *\,':,-'
\ ._ , .. . ,~ · , , '\. . , . H-C -C- C-0 -H
(8) Tripte covolent bpliq/ -t~iple/:!: / e =·C/CH
"' ... '$_ '' \- •· ., ).;\:.<:-,_ ' ,,' ,, ''
I I
H H
=CH _ ~ .···,~- ·~/· './,·\ .\ :,\.~
(C) Ethyne , "'-, . -. ">. ,; , .\• :, ,;, ,:,, \, · [Marking Schem e]
(D) AUca'ne . , }., · "</\~~~\'c,~";,: __c'.';:
(E) Single covale ,it ~9qd/:jJri;gl~j/:~-/ -/; }vJ What Examiners say
(F) Methane .
'~-\,' ..,:,,,;;~.\(\"\~(
-,\,'{",\_·~
·· , · -,---- ,,--, <•.'0(
"- (A) Some candidates did not comple te the
' ',: · : -" '~:~:.:;~>·\~; structure with adequate numbe r of H atoms.
'' .· .. :~j:}!1 ~~\t~~i,rJ,0~,,;;, e
"- (8) Diethy l ether was confused with aceton
w-J What Examiners say or ketonegroup instead of oxygen linking
.,. Some candidates made the followi ng mistakes in the 2 ethyl groups.Some candidates erred
· completing the table which relates to the homolo gous by substit uting the ethylgr oup with methy l
series of hydrocarbons: group in ether.
Name of compo und was written in place of "- (C) Condensed formul a of the acid group was given
homologous series;
by some candidates; others made errors such as
The characteristic bond was referre d to as
linking the C in the carbox ylic group with H.
unstaturated/s aturate d instead of triple covale nt
bond and single covale nt bond respectively; 152. Identi fy the term or substa nce based on the
The IUPAC name of the first memb er of the alkyne s
descriptions given below:
was given as methyn e.
(A) Ice like cryst als forme d on coolin g an
Ut. Draw the structural formu la for each of the organ ic acid suffic iently .
following:
(B) Hydrocarbon containing a triple bond
(A) 2, 3 - dimet hyl butan e used for welding purposes.
(B) diethyl ether (C) The property by virtue of which the
(C) Propanoic acid [ICSE 2017] compound has the same molec ular
Ans. (A) 2, 3 - dimet hyl Butan e. formula but different structural formulae.
H H H H (D) The compound formed where two alkyl
I I I I 0
H-C -C- C-C -H II
I I I I groups are linked by - C - group.
H CH 3 H H [ICSE 2018]
(B) Diethyl Ether
Ans. (A) Glacia l Acetic Acid.
H H H H
I (B) Ethyn e or Acety lene
I I I
H-c -c-o - c-c -H (C) Isome rism
I I I I (D) Keton e
H H H H
0

____ _ ;,. r hom i c::trv I~ L...Aa

 {A) glacial acetic acid
& caution
.,. Understand the basic rules of ~UPAC nornen
(8) acetylene or ethyne selection of the longest cham and the .., clat1.1re
(C) Isomerism t he ,,,a,me, ·
numbering ofC atoms. of
(D)Ketone
[Marking Scheme] 154• Give the structural formula of the followin .
~-han ~ i
~ What Examiners say (B) 1-propan al
-. Most of the candidates answered this part correctly. (C) ethan~lc acid
Some candidates failed to associate the word 'glacial' (D) 1, 2-dlchloroethane. [ICSe ]
with acetic acid.
2014
Ans. (A) H H
'-t Many candidates wrote alkyne instead of ethyneor
I I
acetylne. H-C-C -OH
'-t Some candidates wrote 'Isotopes' or 'Homologous
series' instead of 'Isomerism '.
I I
H H
.,. A few candidates referred to the compound as 'Keto
group' or 'aldehyde group' Ethanol
(B) H H H
,& Caution I I I
'-t Develop clarity among the various terms in organic H-C-C -C=0
chemistry by discussing the meanings of similarly
sounding or meaning words. I I
H H
153. Write the IUPAC names of each of the
1-Propanal
following :
(A) H H H
(C) H 0
I I I I II
H-C= C-C-H
H-C- C-O- H

I I
H
H
Ethanoic Acid
(B) H H
(D) Cl Cl
I I
H-C-C =C-C -H I I
H-C~ C-H
I I
H H I I
H H
(C) H H
1, 2-dichloroethane
I I
H-C-C =O 155. Give the structural formula for the following:
I (A) Methanoic acid
H (B) Ethanol
Ans. (A) Prop-1-ene
(C) Ethyne
(B) But-2-yne
(D) Acetone
(C) Ethanol
(E) 2-methyl propane. pCSE 2012]
(A)Propen e
(B) but-2-yne
Ans. o
(C) ethanol II
(A) Methanoic Acid: H - C - O - H
[Marking Scheme]
(B) Ethanol
wJ What Examiners say H 0
'-t The following errors were made by candidates
(A) 2 propene or prop - 2 - ene I II
(B) but - 2 eyne or butyne H-C-C -H
(C) ethanol or 2 - ethanol or ethanoic acid I
_,. Incorrect symbols used due to lack of understanding
H
of the trends in periodic properties.
(C) Ethyne H - C = c _ H
•
490 /.. EduCart ICSE Chemis try Class x
(D) Acetone (E) 2 -Methyl Propane
H

~-:-----
H H H
H- b I I I
I .,,.....--- c =o H- C- C- C-H
H-C _,../' I I I
I H I H
H
H-C-H
OR
I
CH 3 ~ H
CH /C=O
3
 ICSE
SPECIMEN PA PE R
(SEMESTER-2)
20 DECEMBER, 2021
SOLVED

C H E M IS TR Y
Time Allowed: One and a half hours
Maximum Marks: 40
Gene ral Instru ction's:
Attempt all qu.estions fr~~ ·SectionA··d nd'any ,:~hiei ,ciG~~
ti;nsf rom Section B.
The intended marks'for:
✓ ~
~~~st;b~~];,'.iari~1¥;~titiJ~i~:Ji~ :gi;e~.
'" •
;.\&i--/i</v~(i t/,,/ff'/,/J,A I':.;''? •/ ' ' • i~
:• {.,'. '"-•, : ~ : , '\,•~-\ 'j;~~~(
,
·~rackets [ ].
f

SECTION - A [10 marks]

(Attempt All questions)

1. Choose the correct answers to the questions (D) The cataly st preferred in the conversion
from the given options. (Do not copy the
of Sulphur dioxide to Sulphur trioxide is:
question. Write the correct answer only.)
(a) Finely divided iron
(A) The IUPAC name of Ethylene is:
(b) Graphite
(a) Propa ne
(c) Vanadium pentoxide
(b) Propyne
(d) Platinum
(c) Ethene
(E) Substitution reaction is a characteristic
(d) Ethyne
property of.
(B) Carbon to carbon double bond is found
(a) Alcohols
in:
(b) Alkanes
(a) 2-but ylene (b) Acetaldehyde
(c) Alkenes
(c) Acetic acid (d) Ethyl alcohol
(d) Alkynes
(q Fused alumina is reduced to aluminium
by electrolytic reduction, since: (F) The gas evolved when dilute sulphuric
acid reacts with iron sulphide:
(a) Alumina is highly stable
(a) Sulphur dioxide
(b) Alumina is least stable
(c) Alumina is not reduced by drying (b) Carbon dioxide
agent s. (c) Hydrogen sulphide
(d) Alumina is not reduced by reducing (d) Nitrogen dioxide
agent s (G) An acid obtained from concentrated
nitric acid on reaction with Sulphur:
0
492 ldl:!:, Educ:;'art ICSE Chem istry Class X
 (a) Carbonic ,., .
... c,d
(b) Sulphuric acid
(c) Nitric acid
(d) Hydrochloric acid (I) The chemical nam e of the
principal ore
(H) The hydroxide of aluminium :
.
am mo niu m hy drsol.uble In (a) Sodium aluminium flu
oride
oxide Is· excess of (b) Aluminium oxide
(a) Zinc hydroxide .
(c) Hy dra ted Aluminium
(b) Lead hydroxide fluoride
(d) Hy dra ted aluminium
(c) Magnesium hu d . oxide
:::1 rox1de
(J) A.hyd roc arb on which is
(d) Ferrous hydroxide gas . a gre enh ous e

(a) Acetylene
(b) Ethylene
(c) Eth ane
(d) Me tha ne
SECTION - B (30
(Attempt ~~ !U_hree
. marks
-- - questions from th' S }
(A) Define: is ect1.on)
(1) Ca ten ati on
(B) Sta te
the following:
(2) Alloy
[2] (1) The drying age nt
(B) Name the used in the
co mp ou nd formed when: lab ora tor y pre par atio n of
HCl gas .
(1) Eth en e rea cts wi th (2) Pro duc ts formed wh en
hydrogen in the am mo nia is
pre sen ce of a cat aly st. bu rnt in excess of oxygen
(2) Bauxite
. l21
rea cts with sodium hydroxide (C) Sta te the
observation for the follow
ing,
wh en:
[2]
(C) Draw the str uc tur (1) Ma nga nes e
al dia gra m of: dioxide rea cts wit h
(1) Pr op an al con cen tra ste d HCL
(2) Ethanoic acid
(2) A gla ss rod dipped in
(3) 1,2 dichloroethane con cen tra ted
[3] HCl acid is bro ugh t nea r
(D) Complete an d ba am mo nia
lance the following gas .
chemical eq ua tio ns :
(1) C2Hs + 02 ➔ (3) Co nce ntr ate d sulphu
ric acid is
(2) C2H2 + 12 ➔ add ed to carbon.
(3]
(3) NH 3 + HO ➔ (D) Write bal anc ed equ
(3] ati on for the
following conversions:
l. (A} Identify the an ion pre sen t in
the (1) Lead sup lha te fro m
following co mp ou nd s. lea d nit rat e
and sulphuric acid.
(1} Co mp ou nd z which on reacting (2) Nitrogen tri chloride fro
wi th dilute sulphuric acid m am mo nia .
liberates
a ga s which ha s no (3) Sodium chloride from sodium
effect on sul phi te and dilute hyd
acidified po tas siu m dichro rochlo ric
mate bu t
tur ns Ume wa ter milky. acid. l31
(A) Sta te the rel eva nt
(2} The sol uti on of
Compou nd L on
4. reason for the
rea cti ng wi th freshly following:
prepared
fer rou s su lph ate solution (1) A lay er of powere d col<.e is used
followed .
over the electrolyt\c mixture
by ad dit ion of few in Hall
drops of He rou lt's process.
co nc en tra ted sulphuric aci
d to the d are continuously
rea cta nts alo ng the sides (2) Graphite don~ es the
electr<>lysis of
of a tes t replaced urmg
tub e for ms a brown rin [2]
g at the alumina.
jun cti on of the tw o r,q uids (l)
· 0

sp ec im en paper 1 T'I!.. 49 3
l::::£J
 (3) The compound formed by co
alloys for the given chlorination of ethyne.
Name the l'nplet.
(B) composition:
[~
1 Magnesium and aluminium (D) Answer the fo llowing questions re!ft.._.
() . M n anese + to the laboratory preparation :""'<I
(l) Magnesium + a g
[2] hydrogen chloride gas: Of th,
Aluminium + Copper
(1) Why la sodium chloride Preferre [~
(C) Identify the t erms for the following: other metallic chlorides? d to
(1) The experiment which demonstrate s (2) State the temperature required .
high solubilit y of ammonia gas. the preparation. 1n

(2) A method used to collect HCl gas. (3) Write the chemical equation. [3]
(3) The electrode where reduction
takes place. &. (A) Distinguish between the following:
(1) Dilute HCl and dilute HN0 [u ,
(D) Complete the table given below: [3] silver nitrate solution] 3
sing
(2) Dilute HCl and dilute H2S04[USi
Name 1tea'a:b;
oft he ',,,'.:\/ lead nitrate solution] [~
process ',, , ~~~'
(B) Give one word for the folloWing
(1) Nitrogen (2) ............... statements:
dioxide+
(1) Naturally occurring minerals frorn
water+
oxygen which metals are extracted.
(2) Organic compounds having the
Oleum+ Sulphuric
I (3) ........ water acid same molecular formula but
different Structural formula. [2]
s. (A) Write the balanced chemical equation
to show the concentratio n of ore in (C) A, B and C are the chemical properties
Bayer's process. of sulphuric acid:
(1) Sodium aluminate to aluminium (1) Oxidizing agent
hydroxide (2) Dehydrating agent
(2) Aluminium hydroxide to alumina [2] (3) Non volatile acid
Match the following equations (i) to
(B) Select the correct answer from the
0iQ to the above chemical properties of
brackets to complete the following
sulphuric acid.
statements:
(Q KN03 + H2S04 ➔ KHS04 + HN03
(1) The catalyst used in the oxidation
of ammonia is ............... [zinc / (ii) C12H22011 ➔ 12C + 11H20
platinum]. (iii) S + 2H2S04 ➔ 2H20 + 3S02 [3]
(2) The product formed when ammonia
(D) Study and complete the following table:
reacts with oxygen is ............... [nitric
oxide/ nitrous oxide] [2]

(q Name the following organic compound:

(1) The compound with 3 carbon
atoms whoae functional group is a
carboxyUc acid.
General for-
mula _,
·······•........
IUPACname 2. ............... Ethyne
(2) The firlt homologue whose general
formula is CnH2n• Common name Marsh gas 3.
. ........::.•.::::.~

~-
._____ (3)

•
494 Cl/, Educ:;'ort ICSE Chemistry Class X
 S O L U T IO N S
~----------SP
--EC1tv1EN PAPER- 1
==;:.::_:=-:__ __ _
(A) (c) Ethene SECTION A
~ Explanation: The IUPAC nam
e Of (E) (b) Alkanes
Ethene. Th e structure of eth
ylene isethylene ts ·
H- C= C- H Explanation: Alkane s are
the compounds
having general formula CnH
I I of alkane is satisfied by 2 n+2.The valency
H H single bond only.
Hence, it gives substitution
reactio ns only.
The word root is eth which (F) (c) Hy dro gen sulphide
. is used flor
ato ms an d su ff 1x 2 car bon
use d in alk ene is ene . Explanation: FeS +- H SO ~
(B) (a) 2-b uty len e. 2 4 H2S4+ FeSO
4
Explanatio~: The structu (G) (b) Sulphuric Aci d
2-butylene 1s ral for mu la of
H H Explanation: Nitric Acid is
an oxidizing acid
I and it can oxidize sulphur.
I
H -C -C = C- C- H S + 6HN03 ➔ H2S04 + 2H
20 + 6N02
41 31 21 11 (H) (a) Zinc hyd rox ide
H H H H Explanation: The precipitat
But me ans 4 car bo n in a ed Zn(OHh is
ser ies and due to soluble in excess of NH
presence of suffiix en e at 0H . It for ms
double bo un d is pre sen t.
sec on d position colourless, wa ter soluble am4
mi ne complex.
Moreover double bon d is (\) (d) Hy dra ted alu min ium
pre sen t in between oxide
2-carbon ato ms . Explanation: The nam e of ore
of Aluminium
(C) (a) Alumina is highly sta is Bauxite. The formula is Al
ble. 20 3.2H20.
Explanation: Th e Alumina (J) (d) Me tha ne
is highly sta ble
in nat ure. Explanation: Methane is gre
en house gas
(D) (c) Vanadium Pentaoxi bec aus e the y absorb hea t
de The se mo lecule s
eventually release the hea
Explanation: 2S 0 + 0 t ene rgy and it
2S 0 3 t is often absorbed by ano
2 2 the r gre enh ous e
gas molecule.

2. (A) (1) Catenation: It is a self-linking pro per

of car bon . Ca ten ati on is
ato ms of the sam e ele me
SECTIONS

the bonding · of
ty (liQL
(lv)o
nt into a series,
called the chain. Th e cha in
ma y be open,
closed or ring on e.
(0
-C -C -C -C -C - C -
\ I I I I I (2) Alloy: An alloy is an adm
ixtu re of meta ls
00 I I or a me tal combined with
one or mo re
- C- C - C- C- oth er elements. The res
ulting mixture
for ms a substa nce wit
1 I I I h properties
tha t often differ from tho
se of the pure
- C- metals, such as increased
strengt h or
l har dne ss. Alloys are the
homogeneous
- C- mixture.
E.g. Duralumln is an alloy
l of Aluminium
for me d up of9 5% Aluminium
-C - , 4% copper
.5% Ma nga nes e and .5% Ma
gnesium.
l
0
JII!_
sp ec im en Paper 1 ~ 49 5
 Wh ethene reacts with Hydrogen
(B) (i) . :~esence of Nickel, Palladium or
inlatinum cataly st at 200°C t o give
(2) Iodine reacts slowly in Pre '
alchoh ol to form di-iodo ethenscence of
c2H 2+1 2 ~CH l
e.
I

~thane gas. The reaction is called

111 II
Hydrogenation reaction.

CHn
II + H2
Ni
>I
CHJ
CH CHI

(3) When ammo nia reacts w ith HCl .

CH 2"'-._) 200°C CH , it res l
3 in forma tion of Ammo n ium chloride ut
(ethene) (et hane)
NH 3 + HCl ➔ NH4Cl .
(2) When Bauxite reacts with Sodium
Hydroxide at a tempe rature of 150-
3. (A) (1) The anion present in compound .
2000C, it result in forma tion of sodium
.
carbon ate 10n. Th" . b
1s 1s ecause th z IS

which have carbonate ions, rele e Salt

aluminate.
- "d .h b .
Al20 3 + 2NaOH ➔ 2NaAl 02 + H20
carbon d 1-ox1 e wit nsk efferve ase
senee
when they react with dil H S0 . The
(C) (1) Propanal 2 4
.
turns l ,me water m1"lky while it do 9as
The struc_ture of propanal is CH3CH2CHO · · ct
or H H
give any 1mpa on act·d·fi d not
I e potassuiurn
H
dichromate.
I I I
H-C -C-C =O Na C0 + H2S0 4 ~ NaHSO 0+ H 0+ co
2 3 4 2
(dil) 2
I I
H H (2) It have the nitrate ion as anion or acidic
,& Caution radica l Because the brown ring is used
-+ The word root is prop which means three carbon to detect nitrate ion in compound.
and the suffix used is all that is aldehy de group. (B) (1) Concentrated sulphuric acid (cone.
(2) Ethanoic acid:
The struct ure of H2S0 4) is used as a drying agent
ethan oic acid is CH 3COOH . for purifying HCl gas, as H S0 is
2 4
H 0 Hygroscopic in nature and it absorbs
moisture from air.
I II
H-C -C- 0-H (2) When ammo nia gas is burned in oxygen,
I the products forme d are water and
.H nitrogen monooxide gas.

Ethanoic acid is also· known as vineger 4NH3 + 502 ➔ 4NO + 6H20

or acetic acid. (C) (1) When Manganese dioxide reacts with
,& Caution cone. HCl gas. a gas evolved with
-+ The word root is eth that means two carbon with punge nt suffocating odour.
suffix oic acid i.e. carboxylic acid.
Mn0 2+ 4HCl ~Mn Cl + Cl +J~Q)
(aq) 2 2
(3) 1, 2 dichloroethane: The struct ure of
1, 2 dichloroethane is (2) When a glass rod dipped in concentrated
Cl Cl or CH - CH HCl acid is broug ht near ammonia
2 2
I I I I gas, dense white fumes of ammon ium
H-C -C-H Cl Cl chloride is formed.
I I NH3 + HCl ~ NH 4Cl
H H (3) When cone. H2S0 interacts with carbon
4
,& Caution it generate carbon dioxide and sulphur
dioxide gas,
-+ Th e wo rd ro ot is et h t ha t is two carbon
ato m attach e d wi th 1 chlorin e atom at both C + 2H3S0 4 ~ CO + 2H 0 + 2S02
2 2
positio ns.
(D) (1) Pb(N03)i + H2S04 ~ PbS04 + 2HN03
(D) (1) 2C2H5 + 70 2 ➔ 4C0 2 + 6H20
(2) NH3 + 3Cl2 ~ 3HCl + NCl3
The compl ete burning (combu stion) of
organic compound result in production (J) Na2S0 + 2HCl ~ 2NaCl+ Hp+ S02
3
(dil)
of CO 2 and H20 .
0

496 ldGJ Edu ~ art ICSE Chem istry Class X

 , ,
I

(A) (1) The layer of powdered H H

A- the heat loss by radiat· coke reduces (2) C?H -1 (Et hen or Ethylene)
. ion and pr I I
burning of the anode. events
H- C= c-H
(2) During electrolysis of l .
.b a um,na t he Tho Cation formula represent alkenes.
oxygen lI erated at carb ' · must
on anode reacts The first member of the series
wit h graphite rods and fo have 2 carbon atoms in it as t he valency
. 'd H . . rms carbon
d1ox1 e. ence, 1t 1s necessar Y t o replace of carbm, is sat isfied by double bond
.
anode continuously. in alkenes. Hydrogen is not capable to
(B) (1) Magnox (99% Magnesium form double bond.
+ 1%
Aluminium) 1, 1, 2, 2-tetrachloroethane.
Cl 2
CH+ Cl 2 CHCL CHCL 2
(2) Duralumin (4% copper, + .5 _ l%
Manganese + .5 - 1.5% Magnesium + II
95% Aluminium) CHCL CHCL2
CH
(C) (1) Fountain experiment helps to OR
demonstrate high solubility of ammonia CH+ 2Cl 2 CHCL 2
gas.
Ill
(2) By downward delivery or upward
CH CHCl2
displacement of air.
(D) (1) Because sodium chloride is present in
(3) The cathode is the electrode where nature abundantly and it have low cost
reduction takes place. also.
(D) (1) Ostwald's dilution process (2) The temperature required is less than
200°C. Because higher temperature
(2) Acid formed: Nitric Acid (HNO 3) causes sodium sulphate to form hard
Pt
4NH3 + 502 - 7-00-a- 4NO + 6H 2O crust.
80- 0-ac--4)
200 c NaHSO 4 + HO
(3) NaCl+ H2SO 4 below
2NO + 02 -+ 2NO2 . (gas)

4NO2 + 2H2O + 02 ~ 4HNO 3

6. (A) (1) On reacting with dil HCl AgNO 3 gives
(3) Contact chamber process white precipitate. if AgCL (silver chloride)
while with dil. HNO 3. Silver nitrate do
5. (A) In extraction process of Aluminium, Bayer's
not give any reaction.
process is used for concentration of ore. The
reactions involved in this process are: H~l+ AgNO 3 ~ AgCl .J, + HNO3
(d1l) (White ppt)
Al2O3 + 2NaOH ~ 2NaALO 2 + 02 + H2O
(1} NaALO 3 + 2H 2O ~ Al(OHb + NaOH HNO 3 + AgNO 3 ~ No Reaction
1080 c ) Al2O3 + 3H2O (dil)
(2) 2Al(OHh
(2) On heating lead nitrate to dilute Hd. it
(B) (1) Platinum
will form a white precipitate which will
700- 800 C dissolve on heating the solution whereos
4NO+6Hp
Pt
on reacting with dilute sulphuric acid
(2) Nitric Oxide it will form a precipitate which will not
dissolve on heating.
4NH3 + 502 100-:00 c 4NO+ 6Hp 2HCl + Pb(NOJ)2 ~ PbCl2 l + 2HN03
(Nitric Oxide) H 2S0 4 + Pb(NOJ)2 ~ PbS04 l
+ 2HN03
(C) (1) Propanoic acid (CH 3 CH 2 COOH)
For corboxylic acid w e use-fi.m ctional (8) (1) Ores are t he naturally occuring minerals
group -COOH and the suffix use is ale from which m etals are extracted. All
acid while for t hree ca rb on, we use ores are minerals while all minerals are
word root prop. The functional group not ores.
contains a carbon In it. Hen ce, its (2) Isom ers are the compounds having
carbon will be counted in chain . sa m e molecular formula but the~ differ
in their structural all formula and this
CH3 - CH 2 - COOH
phenomenon is known as isomerism.
(Propanoic Aci d)
•
Specimen Paper 1 rrI!
t:=- 497
(C} (1) (C} Non-vola (2) Acetylene
tile acid
(2) (B) De hydrat ing The common nam
agent e of
acetylene having ge
(3) (~ Oxidining ag
ent neral for ethYt'le is
(0 ) (1) CnH2n-2 H - C = C- Hrnuta r_
'-2 Hi.
(3) Methane
Alkyne have general
formula of CnH2n-2· The Marsh gas is
In Alkane the the va
satisfied by triple Bo
lency of carbon is Methane having form also k
nd. The fist member ula CH nown a )
4.
of alkyne have 2 carb
on.
 ICSE
SA MP LE PAPER
(SEMESTER-2)
SOLVED

CH EM IS TR Y
Maximum Marks: 40
r,me Allowed: One and a half hours

General Instructions: Same· fhstructions as given in_the s,a~ple Paper ·1.

SECTION - A [10 makrs]

(Attempt ~~ questions)

(E) The IUPAC name of forma ldehyd e is:

1. Choose the correct answe rs to the questions
from the given options. (a) Ethanol
(b) Propan al
(A) If t,he molecu lar formul a of an organi c
compound is C10H1s, it is: (c) Metha nal
(a) Alkane (b) Alkene (d) Ethanoic acid
(c) Alkyne (d) Alcohol
(F) When concen trated sulphu ric acid
(B) The proper ty of carbon to form chains reacts with NaOH. the produc t forme d
and rings is called: is:
(a) Catena tion (a) NaOH
(b) Polymerisation (b) Na2COs
(c) Cracking (c) Na2S03
(d) Oxidation (d) NaHS09
(C) A chemical process of extract ing a (G) Which acid is prepar ed by Ostwa ld's
metal from its ore is known as: process?
(a) Mineralogy (a) Nitric Acid
(b) Metallurgy
(b) Oleic Acid
(c) Uquation
(c) Sulphuric Acid
(d) None of these
(d) Tartari c Acid
(D) When dilute sulphuric acid reacts with
(H) An aqueou s solutio n of HCL is named as:
zinc sulphide, the gas evolved is:
(a) Aqua Fortis
(a) Hydrogen sulphide
{b) Sulphur dioxide (b) Aqua Regia
(c) Oil of Vitriol
(c) Sulphur trioxide
(d) Muriatic acid
{d) None of these
0

Samp le Pape r 2 lit, 499

 Cl
The magnetic ore is:
(I) I
(a) Haematite (b) CH3 - CH2 - CH - CH 3
(b) Zinc Blende I
(c) Alumina Cl
Cl Cl
(d) Copper Pyrite
I I
(J) The structure of 2,3-dlcheoro-u-
(c) CH3 - CH - C - CH 2 - CH
methylhixane is: I 3
(a) CH3 - CH-CH - CH-CH2-CH3 CH 3
I I I Cl CH 3
Cl Cl CH3 I I
(d) CH3-C-CH-CH 2 -cH 2-CH
I 3

Cl

SECTION - B [30 marks]

(Attempt any three questions from this Section)

2. (A) Define: (2) Aqueous solution of ammonia gives

a ,Jungent smell, why? 121
(1) Unsaturated Hydrocarbon
(B) State an observation for following:
(2) Calcination [2]
(1) Aqueous solutions of HCl acid is
(8) Name the compound formed when: passed on Methyl orange.
(2) Aqueous solution of ammonia
(1) Methane gas is treated with
(Ammonium hydroxide) is passed
chlorine in presence of sunlight
on copper sulphate solution. [2]
(2) The Hydrolysis of sodium aluminate
~~p~~ ~ (C) State the following:
(1) Magnesium metal is heated with
(C) Draw the structural diagram of:
dilute sulphuric acid
(1) 2-Methylpropane
(2) Propan-1-ol (2) Product formed when nitrogen
reacts with hydrogen in presence af
(3) Vinegar [3]
iron catalyst at 450°C and 200 atrn
(D) Complete and balance the following (3) Product formed when Hct gas is
reaction. passed in ammonium hydroxide
(1) CH2 + HBr ~ solution. [3]
II (D) Write balanced equation for the
CH 2 following conversions:
(2) CH+ HO~ (1) Sulphur dioxide from sulphur and
Ill concentrated sulphuric acid.
CH (2) Ammonium nitrate from
ammonium hydroxide and nitric
(3) Zn + H2S04 ~
acid
(dil) [3) (3) Cooper nitrate from hot and dilute
nitrio acid or cone. HNO. [3]
3. (A) Give the answers of the following
questions by identifying the anions 4. (A) State the relevant reason for th e
present in salt. following: (2)
(1) Why brisk effervescence Is seen (l) Why are metals called reducing
when H 2S04 is added to metallic agents?
salt?
(2) Why extraction of aluminium is
difficult?
0

500 Ci1, EduC:art ICSE Chemistry Class X

 (B) Give two use s for th fo
(1) Du ralu min e llowin ll
9 a oys:
(2) Fifth Homologue of Alkane
(2) Ma gna lium series.
(3) Compound uaed to preserve ani
(C) Identify for the following [l ]
mals.
:
(1) The [3]
ele me nt \Nh ' h
reducing age nts . ic beh ave (0) Give the following questions related
as to
(2) The nat ure of a the:
l .
con ver ts blu e litm usso ut1o
to red.n w h'ic h
(1) How will you dry HCl acid
gas?
(3) A sat ura ted sol utio n of a (2) Give two tes ts of HCl.
wa ter. . .
rnrnon1a m (3) Which two colourless
gas es
[3] combine to form white soUd?
(D) Co mp lete the following [3]
tab le: 6. (A) Name the following:
Nome of Tem per atu re Ca taly st (1) Name the cat aly st
used in the
process Equation contact process.
for
(2) Name another one which on
Cat aly sed reacting
gives sulphur dioxide.
~
reaction [2]
\Hober's (A) .......... (B) .......... (B) Give one word for the
I (C) .......... following
process statements:
(1) Name an ore of cop
per which is
[3] sulphide.
5, (A) The following que stio ns rela (2) Process by which eth
ane is
te to the obtained from ethene.
ext rac tion of alu min ium by electrolys [2]
(1) Give the equ atio n for
is.
the reaction (C) Sta te how you can obtain
tha t tak es pla ce at the cat hod :
e. (1) Sulphur dioxide form sul
(2) Explain wh y it is necessary phur
to renew (2) Potassium
the ano de from tim e to time. bisulphate from
(B) Sel ect the cor rec t ans [2] sulphuric acid
we r from the
bra cke ts to com ple te the (3) Zinc sulphate from zinc nitr
following ate [3]
sta tem ent s.
(1) __ _ .. is use d as cat (D) Study 8t complete the followi
aly st during ng tble :
pre par atio n of am mo nia .
(Iron/
Mo lyb den um )
(2) -·- ··· tur ns tur me ric, pap
er brown. (1) IUPAC name
(Ammonia/Nitric Acid)
[2]
(q Name the following org ani c (2) Bond type
compound:
(1) An org ani c com pou nd (3) First member of series : ........
u,s ed in food .......
ind ust ry.

PI!_ 501
sa mp le Paper 2 l::::I:!J
 SOLUTIONS
SAMPLE PAPER- 2
- - - - - - - - - - - -S-EC
-T--
10:-:-N-:-A- - - - - - - - -~
(F) (c) Na2S0 4
1. (A) (c) Alkyne
Explanation: 2NaOH +H-iSQ4-, 21--1_
~lanatl on: The General formula of Alkyne ''20 +~k.J, 'r
is C11H21, _ 2_The compound c10 H18 is following (cone) r Ji
the forrnula of it Hence, it is an alkyne. (G) (a) Nitric Acid
(8) (a) Catenatio n Explanation: Nitric Acid is manufa
Explanation: The property of self-linking Ostwald's process. ctured ~'.J
of atoms of an element through covalent
(H) (d) Muriatic acid
bonds in order to form straight, branched and
cyclic chains of different sizes is known as Explanation: Glauber prepared the .
catenation. 1648 by heating com~on salt (Na~a,d_r, 1

(C) (b) Metallurg y cone. H2S04 and named 1t Muriatic ac"d Mt},
I .
Explanation: The extraction or isolation of (I) (a) Haematite
metal form its ore is known as metallurgy. Explanation: Haematite is the ore of iron.
(D) (a) Hydrogen Sulphide , (J) (a) CH3-C H-CH-C H-CH2 -CH
Explanation: ZnS + H2S0 4 ➔ ZnS04 + H2S 3
(dil) I I I
(E) (a) Methanol Cl Cl CH3
Explanation: The formula of Formaldehyde Explanation: Word root Hex, means 6-carb
is HCHO. It have a single carbon, Hence meth
is used as word root and due to presence of
in chain on 2 & 3 position chlorine is
while on 4 methyl group is added.
attach:
aldehyde group suffix al is added.
SECTION-B
2. (A) (1) Unsaturated Hydrocarbon: The hv
Hydrocarbons in which valency of CHCl3 + Cl2 CC4 + HCl
carbon is satisfied by either double tetrachloro methane
or triple bond, then it is known as (2) Sodium hydroxide and aluminium
unsaturated Hydrocarbon. If double hydroxide
bond is present, then it is said to be NaAl02 + 2H 20 ~ NaOH + Al(OHh
alkene having general formula CnH 2n (C) (1) 2-methylpropane
while if triple bond is present then it is CH3-CH -CH 3
said to be alkyne having general formula
I
CnH2n-2· CH3
(2) Cal.cination: The conversion of ore into Explanation: Word root prop means three
its oxide in absence of air is known as carbon atom and methyl group is on second
Calcinatio n. It is done for carbonate or carbon.
Hydrated oxide ore. The gas evolved is (2) CH3 - CH2 - CH20H
carbon dioxide gas. Explanation: Word root prop means three
carbon atom having OH group at first position.
(B} (1} The reaction between methane and
(3) CH3COOH or CH 3 - C - 0
chlorine is a multi -step reaction
and results in production of several I
OH .
compound s. Vinegar is common name of ethonoic
-hrl acid. eth means two carbon atoms whila
CH4 + Cl2 CH3Cl + HCl oic acid mea ns carboxylic group.
chloro methane (D) (1) CH2 + HBr~ CH3
hv
~ CH2Cl2 + HCl II I
dichloro mothun e CH2 CH2Br
(2} CH + HCl ~ CH HCl CH3
2
Trichloro methan e Ill 11 I
or CH CHCl2
Chloroform
CHCl

502 CG, Edu ~ ort ICSE Chemist ry Class X

,, (A) (1) Brislk ~ffervescence .
evo ut1on of c b is seen du
.
onion pres ent inor on d'ioxid e ge to th
e (3) N2 + 31-1 2 ~ 2NH + Heat
ion as the gas ev cf rnP?Und is ca~ · The 3
N0 CO O
Ved is c o 0
nate S. (A) (1) The follo wing reaction take
2 3+ H2So 4 ~ N 2· s place at
the cathode durin g the extraction of
(2) Aqueous solu t ion f a2SO 4 +H20
+ CO 2 aluminium
pungent sme ll be~au~: ~o_nia give
s a Al+3 +3C - 4 Al
due to bacteria l d : it is Produced
(NH 3CONH 2), prese~~~mp~sition of urea (2) Oxygen gas is produced at grap
1n urine.
hite
anod e, whic h combines with carbon
(B) (1) ~queous solu tion of HCl is to form CO 2 gas at high temperature
in natu re. Hence th
strong acid and thus anode destroys away. Thus,
chlon'de get convert'
edet 0 oran
. g_e methyl it is necessary to renew the anode to
(2) A pale blue colour prec' .Pink 1s colour continue the process of extraction of
· aluminium.
Hydroxide is formed w~~~":e of copp
er
excess of amm oniu m h d 1.s soluble (B) (1) Iron (Iron is a catalyst used
Y rox1de in in Hab er's
CuSO4 + 2NH 4OH ➔ (NH ) SO . process)
4 2 4+C
(C) (1) A gas evolves with pop up soun u(OHh (2) Ammonia (As ammonia behave as
a
d. base)
Mg + H2SO4 ~ MgSO4 + H2 t (C) (1) Acetic Acid (CH COOH) (Acetic
3 Acid is
(2) Ammonia gas will be formed. also known as Vinegar which is used in
food industry)
N2 + 3H2 , Fe/Mo (2) CsH12fPentane
200atm + 450°C ' 2NH 3 Explanation: General formula of alkane
(3) Ammonium Chloride will be form is CnH 2n + 2· On putting n = 5 we get a
ed formula C5H12.
HCl + NH4OH ~ NH Cl + H o
4 2 (3) Formaldenple (HCHO): Solution
(D} (1) S + 2H2SO4 ~ 3SO2 + 2H 0 of
formaldehyde.
2
(2) NH40H + NH03 ~ NH NO + (D) (1) HCl gas can be dried by pass
4 3 H2o ing it over
cone H2SO 4, which act as powerfu
(3) Cu+ 4H NO 3~ Cu(NO3h + 2H O l
2 + 2NO 2t . dehydrating agent.
4. (A) (1) Metals hav e tend enc y to loose
electrons. (2) Test for HCl:
Hence, they act as reducing agents.
Explanation: It gives dense whit e fumes
(2) Extraction of aluminium is diffi with rod dipped in NH 4OH solution
cult
because:
NH4OH + HCl ~ NH4Cl + H2O
(i) Pure Aluminium oxide melts
at (3) It turns moist blue litmus red.
2050°C. So, a large amo unt of
energy is nee ded to maintain high 6. (A) (1) V2Os
tem pera ture . VO
2SO 2 + 0 2 ~ 2SO 3
OQA good amo unt of aluminium
vaporis es at this temperature. (2) Zinc Blende or Zns.
2ZnS + 30 2~ 2ZnO + 2SO 2t
{B) (1) Duralumin: It is used in manufacturin
g (8) (1) Copper Pyrite (CuFeS'.2)
of bodies of aircraft, light tools, pressure
(2) Hydrogenation
cooker etc.
(2) MagnaUum: It is used in making met ~
CH + 2H2 200 c CH3
al
mirrors, bea ms of bala nce etc. 111 I
(C) (1) Metals CH CH3
Explanation: Because they have tendency
to (C) (1) S + 0 2---- t SO2
loose electron s.
(2) KCl + H2SO 4----t KHSO4 + HCl
(2) Acidic
Explanation:The add converts blue litmus to (dil) .
red. (3) Zn(NO3)2 + H2SO 4----t ZnS 0 4+ 2HN
(3) Liquor amm onia fort is. 03
. (D) (1} Alkene (gen eral formula)
Explanation: It is also called 8 8 0 ammonia
.
(D) (1) 450 - S00°C (2) Double bond
(2) Finely divided iron (3) C2H4 or CH2 ;: CH2

sam ple Paper 2 rr~

l::::Ii:J 50 3
 ICSE
SAMPLE PAPER
(SEM ESTER-2)
SOLVED

C H E M IS T RY
Time Allowed: One and a half hours
Maximum Marks:
40
General Instructions: Same instructions
, ,
;'/:;,?
•/, '., , , , ,V/ ,"' <

as given in the Sa,mr:?,le Pap~r l : /,, ,, ,,,

, ,// / , / , ,, 1/ ,, , , , /
<
SECTION - A [10 ma rk]
(Attempt !'ll questions)

1. Choose the correct answers to the questions (F) In the given equa tion identify the role
from the given options.
played by conc entra ted sulphuric acid:
(A) The IUPAC nam e of Chloroform (CHCl )
3 S + 2H2S04 ~3S 02 + 2H 0
is: 2
(a) Non-volatile acid
(a) 1, 1, 1-trichleromethane
(b) Oxidising agen t
(b) Trichloromethanol
(c) Deh ydra ting agen t
(c) Methyle chloride
(d) None of thes e
(d) Chlo rome than e
(G) The brow n ring test is used for the
(8) The compound having functional group
detection of:
alde hyde is:
(a) co 3- 2
(a) Meth anol (b) Ethanal
(c) S03-2
(c) Prop anan e (d) Ethylene
(C)
(H) The amp hote ric oxide is:
An unw ante d earth y mate rial
asso ciate d with ore as impurity is (a) Al203 (b) Cu20
known as: (c) MgO (d) None of these
(a) Gan gue (b) Flux (I) Sulphide ore is generally concentrated
(c) Froth (d) None of these by:
(D) Pyrosulphuric acid is the chemical nam e (a) Reacting
of: (b) Froth float ation process
(a) Green Vitriol (b) White Vitriol (c) Reduction by carb on
(c) Oleum (d) Gypsum (d) None of thes e
(E) The gene ral formula for Alkyl group is: (J) Two neig hbou rs of a homologous series
(a) C,,H2n (b) CnH2n + 2 differ by:
(c) CnH2n - 2 (a) CH (b) CH2
(d) CnH2n + 1
(c) CH 3 (d) CH4

504 6i. 0

Educ;'ort ICSE Che mis try Class X

 ]
SE CT IO N - B [1 0 m ak rs
ona fro m thl • Sec tio n)
(At tem pt an y thr ee que atl • for the
Wr ite bal anc ed eq ua tio n
(D) d Co ne.
(A) De fin e: fol low ing con ver sio ns:
z. (1) Fu nct ion al gro up (1) Su gar cha rco l fro m su ga r an
(2) Sla g [2] hlo 'de
H2 S04 ide for m fer ric c rr
wh en: (2) Fer ric hyd rox
the com po un d for me d .
(B) Na me an d am mo niu m
ct wit h hal oge ne m am mo nia
(1) Eth yne rea (3) Am mo niu m chl ori de for
ium hyd rox ide is hea ted at (3 ]
(2) Alu min an d HCl.
r21
10 00 °c the
rel eva nt rea son for
dia gra m of: Sta te the
(C) Dr aw the str uct ura l 4. (A)
fol low ing :
(1) Ac eto ne
(1) Wh y cry oli te is ad de
d to the bau xit e
(2) 2-m eth ylp rop ane
niu m.
(3) 3-h exe ne
[3] dur ing ext rac tio n of alu mi
fol low ing
(D) Co mp let e & bal anc e the (2) Po wd ere d cok e is spr ink
led ov er the
rea ctio n. xtu re. [2]
sur fac e of ele ctr oly tic mi
(1) CH2 + C l2 ~
(8) Na me the all oy
s for the giv en
II
CH2 com pos itio n:
(2) CH2 + H 2O ~ (1) Co ppe r an d Zin c
[2]
II (2) Co pp er + tin + zin c
fol low ing :
CH2 (C) Ide nti fy the ter ms for the
Bel ow l lec t am mo nia
(3) Na2CO3 + H2SO4 200°c
[3] (1) Th e me tho d to col
gas .
de mo ns tra te
the ani on pre sen t in
the (2) Th e exp eri me nt wh ich
(A) Ide nti fy
hig h sol ubi lity of gas .
fol low ing com pou nds : ox ida tio n tak es
on hea tin g (3) Th e ele ctr od e wh ere
(1) Co mp oun d A wh ich [3]
tes a ga s pla ce.
wit h sul phu ric aci d lib era
ect on aci dif ied
wh ich ha s no eff bel ow :
te bu t tur ns (D) Co mp let e the tab le giv en
po tas siu m dic hro ma
lea d ace tat e pa pe r bla ck. Su bst an ce
on hea tin g
(2) Th e com pou nd wh ich for me d
aci d Ub era tes a
wjt h dil ute sul phu ric ---
gas wh ich tur ns aci dif ied pot ass ium (1) .......... Am mo niu m Ch lor ide + (2)
dic hro ma te fro m ora ng e
to gre en Ca lci um Hy dro xid e
wa ter .
bu t hav e no eff ect on Ume (3) .......... Su lph ur dio xid e + Su lph ur
[2] trio xid e
wa ter
[3]
(8) Sta te the fol low ing :
lea d nit rat e
(1) Pro duc t for me d wh en
ion s rel ate to the
rea cts wi th dil HCl. 5. (A) Th e fol low ing qu est
in lab ora tor y ext rac tio n of alu min ium by
electrolysis.
(2) Th e dry ing ag en t used oth er alu mi niu m
gas . [2] (1) Na me the
pre par ati on of am mo nia ad de d to
for the foUowing. con tai nin g com po un d
(C) Sta te the obs erv atio n alu mi na an d sta te its sig
nif ica nce .
is pa sse d
(1) Hy dro gen chl ori de gas the rea cti on
sol uti on. (2) Giv e the equ ati on for
thr ou gh silv er nit rat e de. [2]
us pa pe r Is tha t tak es pla ce at cat ho
(2) A pie ce of mo ist red litm
mo nia . an sw ers fro m the
pla ced in a ga s jar of am (8) Se lec t the cor rec t
Co ne. H2SO4 the fol low ing
(3) Ca rbo n is he ate d wi th bra cke ts to com ple te
[3] sta tem en ts:
0

Sa mp le Pa pe r 3 ~ 50 5
 (1) Ammonia in liquid form Is ............. .. (8) Give one word for the following
(Acidic/ne utral) statemen ts.
(2) Ammonia gas is collected by ...............
of a ir. (l) The process of removal of Qangue
(downwa rd displacem ent/ from ore.
upward displacem ent) (2) Group formed when alkane looses
[2] a hydrogen atom. [2)
(C) Name the following organic (C) Write the equation for each of the
compoun d:
following reactions.
(1) The hydrocarb on which undergoe s
substituti on reactions. (l) Sulphur is heated with concentrated
(2) The first organic compoun d sulphuric acid.
synthesiz ed in laborator y. (2) Concentr ated sulphuric acid is
(3) Compoun d formed by reaction of poured over sugar.
ethyne and hydrogen . [3] (3) Magnesiu m sulphate solution is
(D) Give reasons for the following: mixed with Borium chloride solution.
(1) HCl gas is not collected over water. [3]
(2) For the preparati on of HCl acid,
HCl gas is not directly absorbed in (D) Complete the following table which
water. relates to following Homologous series
(3) Dry HCl gas does not change the of Hydrocarbon. [2]
colour of blue litmus. [3]
I
i
CnH2n-2
6. (A) Distinguish between the following: !
(1) Dilute HCl and dilute H2S04. (1) IUPAC name of the 1 ·········"·•··

Homologus series I
(Using AgN0 3 solution)
(2) Dilute HN03 and dilute H2S04 (2) Bond type \ ...............
(Using BaCl2 solution) I

(3) Type of reaction with j ...............

[2) Halogene

[3]

506 lJ,, Edu~art ICSE Chemis try Class X

 SOLUTIONS
SAMPLE PAPER-3
SECTION A
(A) (a) 1, 1, 1 - trichloromethane SO 3 + H2SO4 ~ H2S2O4
j, Explanation: Chloroform have a molecular (E) (d) CnH2n+1 . db
formula ofCHCl3 and structural formula : Explanation: An alkyl group is obtaine y
Cl remaining one atom of hydrogen ,~om an
I alkane molecule. It is represented by R.
Cl-C -H (F) (b) Oxidising agent
I Explanation: To sulphur, oxy?~~ is getting
Cl added. Hence, it is showing ox,d,s,ng agent
It has one carbon atom, attached with three (G) (b) N03-
chlorine atoms. Hence the word root used is Explanation: To test Nitrate ion in lab, brown
meth prefix used is chloro. Hence the name ring test is done.
will be 1, 1, 1 - trichloromethane
(H) (a) Al203
· (B) (b) Ethanol Explanation: Al2O3 or alumina is amphoteric
Explanation: The compound having suffix-al in nature.
belongs to aldehyde group. In ethanol the (I) (b) Froth floatatio n process
suffix usded is '-la' Hence it is an aldehyde. Explanation: To concentrate sulphide ores
(C) (a) Gangue such as copper pyrite, zinc sulphide froth
Explanation: The ores, even after their floatation process is used.
concentration, contain, some impurities called (J) (b) CH2
gangue. Explanation: A Homologus series is a group
(D) (c) Oleum of organic compound having similar structure
Explanation: Oleum is a compound formed and chemical properties in which successive
when H2SO 4 react with SO 3. compounds differ by CH2 group.
SECTIONS

2. (A) (1) Functional group: It is defined as an (2) 2Al(OH)3

atom or group of atoms joined in a
specific manner which is responsible for When we heat Al(OHh it results in
the characteristic chemical properties formation of Alumina.
of organic compounds. Eg., Aldehyde (C) (1) Acetone: Acetone is also known as
(-CHO), Carboxylic acid (-COOH) Propanone. Prop word root means three
(2) Flux: To remove the gangue, certain carbon and suffix one is used for ketonse
substances called fluxes are mixed with group. The molecular formula of aceton e
the concentrated ore. The added flux is CH3COCH3.
H H
combines with the gangue to form a
fusible mass called slag. I I
H-C -C-C -H
(B) (l} CHit"" ) CH ~ CHC~ I I I
Ill + c~-.:,. 11 cii >I H O H
CH "-._) CHC U CHC~ (2) 2-Methylpropane: Prop means wo rd
OR root three that means 3 carbon are
present in compound. The suffix used is
CH + 2Cl2 ~ CHCl2
ane that means the compound is alkane
Ill I while substituent group methyl is added
CH CHCl2
to second carbon atom.
The compound form ed is CHCl2 having
CH3 - CH-CH 3
I
CHCl2 I
The name 1, 1, 2, 2 - tetrachloroethane. CH3
0

Samp le Paper 3 6' 507

 (3) When carbon is heated With
(3) 3-Hexen: Word root Hex means thre_e H2so 4, it is oxidised to carbon di co_ nc.
0
carbon atoms and double bond is and acid is reduced to sulphur d'i . X1de
oxide
present in between 3 and H carbon C + 2H 2SO4 ~ CO2 + 2SO 2 + 2H .
atom as -ene is suffix (compound having 20
double bond) and position of double (D) (1) c12 H22OH + H2S04 ~ 12C + 11H2O
bond is at 3 position. Sugar Charcol
CH3 - CH2 - CH = CH - CH2 - CH3 Explanation: Cone. H2SO 4
Oct Os
dehydrating agent.
(D) (1) C H n CH,Cl
II + c~~ I (2) FeCL3 + 3NH4OH ~ Fe(OHhJ.. + 3NH 4C[
CH,\'::.,_} CH2Cl
(3) NH 3 + HCL ~ NH4Cl
Explanation: Alkene undergoes addition (Lime white fumes)
reaction due to presence of double bond
between two carbon atoms. 4. (A) (1) Cryolite Lowers the fusion temperature.
(2) It reduces heat Less by radiation &
(2) CH1 CH 3 prevents burning of anode. ·
II +Hp~I
CH 2 (H.OHJ CHPH (B) (1) Brass (60% - 70% copper + 40 - 30%
~
zinc)
Explanation: Alkene undergoes addition
reaction due to prescence of double bond (2) Bronze (80% Cu + 18% Sn + 2% Zn)
between two carbon atoms. (C) (1) Downward displacement of air as it is
Below 200 C Lighter than air.
(3) Na2CO3 + H2SO4
NaHSO4 + H2O + CO2 t (2) Fountain experiment helps to
demonstrate high solubility of HCl gas.
3. (A) (1) Compound 'A' have sulphide as an anion.
As the gas produced by compound is
Explanation: At anode oxidation takes
H2S which have rotten egg smell. place.
Na2S + H2SO4 ~ Na2SO 4 + H2St (3) At anode oxidation takes place.
(dil)
(D) (1) Laboratory preparation of Ammonia.
When the gas comes in contact of lead
acetate paper, it forms lead sulphide (2) Calcium chloride + water+ ammonia.
black in colour. 2NH4CL + Ca(OHh ~ CaCL2 + 2H 20
(CH3COO)i Pb + H2S ~ 2CH3COOH + 2NH3
+ PbSJ..
(3) Contact Chamber process
(2) The compound B have SO 3- 2 as anion.
The gas produced by compound is SO 2 2SO2 + 03 ViOs ) 2SO3
gas which turns potassium dichromate
from orange to green colour. 5. (A) (1) Cryolite: It act as solvent for pure
Na2S03 + H2S04---? NO2S04 + H2O + SO2t alumina and decreases the melting point
SO2 + K2Cr2O7 ~ green ppt or fusion temperature of pure alumina
(orange) from 2050°C to 950°C.

(B) (1) A white precipitate of Lead chloride is (2) Al 23 + 3e~Al

formed. (B) (1) Neutral
Pb(NO 3)i + 2HCL ➔ PbCL2t + 2HNO3 (2) Downward displacement (Because it is
(2) Quick Lime as it does not react with Lighter than air)
ammonia while other agents such as
(C) (1) Alkanes
H2SO4 and P2O 5 react with ammonia.
Explanation: The valency of alkanes is
(C) (1) A white precipitate is formed which satisfied by single bond only. Hence, they give
is soluble in excess of Ammonium
substitution reaction.
Hydroxide
(2) Urea
HCl + AgNO3 ~ AgCl + HNO3
Explanation: It is synthesized by heating
(2) A piece of moist red Litmus paper turn s
Ammonium Cyanate.
blue when it is placed in a gas jar of
ammonia. This is because of basic nature NH4CNO ~ NH 2 CONH 2
of ammonia. (3) Ethane

508 ~ Educ'ort ICSE Chemistry Class X

 (8) (1) Concentration of ore. .
E)(planatlon· To separate impunty
(gangue) fro~ ore, concentration of ore
is done.
(D) (1) It_is not collected over Water os . . (2) Alkyl group
highly or extremely soluble,·s ,.. it 18
•vater. Explanation: Alkyl group insepreseme d
(2) As the direct absorption leads t b k by R. having general formula CnH2n + 1·
. of Water.
suction o ac
(C) (1) S + 2H 2SO 4 ~ 2H2O + 3SO2
(cone.)
(3) Dry lHQl gos does not change the col
. our
of b ue 1trnus os hydrogen ions ore not (2) C12H 22 o11 + H2so~ 12C + 11H2O
fo rmed in dry state.
(cone.)

(3) MgS0 4 + BaCl2~ BaSO4 + MgCl2

6, (A) (1) Dil HCl gives While Precipitate With
AgN0 3 solution White dil. H2so do not.
4 (D) (1) Alkynes (general formula of alkynes is
HCl + AgN03 ---) AgCl + HN0 CnH2n - 0
3
H2S04 + AgN03 ---) No reaction
(2) Triple Bond (Valency is satisfied by triple
(2) With BaCl2 solution sulphuric acid will bond)
give white precipitate While nitric acid (3) Addition (Dlue to presence . . of
will not give any precipitate.
unsaturated bond alkyne give addition
H2so 4 + BaCl2-- -) 2HCl + BaS04,l, reaction)

J_'/.!., !;09
 ICSE
SAMPLE PAPER
(SEM ESTER- 2)
SE LF ASS ESS M ENT

C H E M I ST R Y
1lrrn• /\llow arl : On11
,-mtl r, hull hour, ,
Mu1.lrr,1m1 Murv,. 1()
General ln1truc;t\o n1
: 6gm o lrn; tru ctlon11 uil glvgn In tho
aomplQ Por,'1 r 1,

SECTION - A [10 mar

k]
(,Attempt AU th • qu
11tlon1)
1.. Ch oo n th • corroct an
1wonJ to th t que11tlo
fro m th • given op tio n1 (a) Sulphuric acid
n, : (b) Nltrlc acid
(A) The lc;om•r of (c) Aceti c acid
pcnt -1-cmi 11: (d) Ammonia
(a) Penton&i (G) Th<i compound
(b) Pi nt -1 -ync du e to which nitric
uxl1t In y1 llo w colou aci d
(c) P(jnt-2 -y n• r 11:
(d) Ptnt-2-ong
(8) Th • prefix uu (a) Nltrogcm mono
d fo r alcohol group oxide
11:
(o) -o l (b) Nltrogon di oxide
(b) -al ,
(c) -olc acid (d) - hydroxy (c) Su lph ur di oxide
(C) Cr1i101Jt:M 11 an ore of: (d) None of tht1ct
{o) Al um ini um (b) Zinc (H) Compound forme
d wh en Nitric aci
(c) Corbon ro ac u wi th am mo d
{d) Lead nia:
(0) Which acid 11 kn (a) Ammonium nlt
own at "KIN G OF ra tct
CHEMICAL&": (b) Ammonium 1u
lphat1
(o) Nltr1c Acid (c) Ammonium Ch
{b) Su lphur1 c avid loride
(d) Ammonium Hy
~ AcA,tlc acid droxldo
{I) Ba ux ltt 11 co ncen tra
(d) Formic add ttd by :
(a) Fro t h flo at at ion
(m TM com pound which proceH
glvH t ub ,tl tu tlon (b) Magnt tlc S1pa
r.actlon• ontw ar• coU.. ra tlon m@thod
d: (c) 8a1y1r'1 proctH
(a) AUwn•
(b) Allutn•
(,) Alk.vn• (d) Hii,draullc wa 1h
(d) Alr,ohal lr1 \J
(f) P) fh@ IUPAC namu of
Th • acid forrm,d Wh A<:. utoldehwde
11n olAtum It dluolvwd (u) Ac-,tlc. od d
jc
In wut«er 11: ,.._
(t;) l'"lh@n e

510 'C1:!:J Educ:'o rt 1c•• Ch om lntr y r 1-l' : . I

 :II
SECTION - B [30 ma rk]
(Att emp t any th
ree que11:fon1 from thl1 Sect ion)

(A) Define:
th e
bala nced equ atio n for
(D) Write
,, (1) Slag
following conversions:
(2) Hom olog ous seri es [2] 'de
er OXJ
(1) Copper sulp hate from copp

(B) Name the com pou nd form ed whe

n: and diL sulphuric acid.
(1) Met hane reac ts with oxygen onia
(2) Nitrogen tri chloride from amm
(2) Calcium carb ona te is heat ed [2] (3) Calcium chloride from cald
um
carb onat e & diL HCL [3]
(C) Draw the stru ctur al diag ram of:
(1) Prop-1-yne s rela ted
4. (A) Answer the following ques tion
(2) 3-hexene of
[3] to electrolysis proc ess in extr acti on
(3) 2-m ethy lpro p-1- ene
aluminium.
following tion
(D) Complete & Bala nce the (1) Write the equation for the reac
reactions: that occurs at the cath ode during
(1) C2H2 + H2 ➔ the extraction of aluminium by
(2) C2H4 + Cl2 ➔ electrolysis.
[3]
(3) NH40H + PbS04 ➔ (2) Explain why it is preferable to
use
the a num ber of grap hite elec trod es as
3, (A) Identify the anio n pres ent in e
following com pou nds: anod e instead of a single elec trod
during the above electrolysis. [2]
ting
(1) Com pou nd A whi ch on reac
sulp huri c acid libe rate s
with dilu te alloys for the given
effe ct on (B) Name the
a gas whi ch has no
composition:
acidified pota ssiu m dich rom ate but
turn s Ume wat er milky. (1) Magnesium and alum iniu m

(2) The solu tion of Com pou nd B

on +
(2) Magnesium + Man gan ese
reac ting with fres hly prep ared (2]
Aluminium + Copper.
ferrous sulp hate solu tion followed
by addi tion of few drop s of (C) Identify the term s for the follo
wing:
conc entr ated sulp huri c acid to the tive
(1) The elec trod e which have posi
reac tant s alon g the side s of a test
char ge on it.
tube form s a brow n ring at the
onia
junc tion of the two liquids. [2] (2) Process to man ufac ture amm
on industrial level.
(8) State the following: red
(3) An indicator which conv erts to
NH3
(1) White den sed fum es form ed by in colour whe n com es con tact to
and HCl (3)
amm onia .
ic
(2) Products form ed whe n Ferr
chloride reac t with amm oniu m (D) Com plet e the tabl e given below:
hydroxide [2]
Nam e of the Rea ctan ts Prod uct form ed
wing :
(C} State the obse rvat ion for the follo proc ess
dll.
(1) Sodium carb ona te reacts with (1) Nitrogen &: (2)
HCL Hydrogen
.
(2) lead oxide reacts with amm onia Con tact cham ber (3)
Sulphuric acid
blue
(J) Cone. H2S0 4 is passed on (3]
vitriol. [3]
0

Sam ple Paper 4

JrI9! 511
t::
s. (~ Nam e the ore and give form ula of the &. (A) Distinguish betw een the followi ng:
ores of following elem ents: (1) Oil HCl &: Oil HN0
3
(1) Zinc (2) OIL HCl 8t dil H2S0 4
(2) Iron [2]
(B) Give one word for the foU
(B) Selec t the corre ct answ er from t he state men ts: owh,g
brac kets to comp lete the following (1) A meta l oxide that can be redu
statem ents. by hydr ogen . ctd
(1) The catal yst used in oxida tion of (2) Orga nic comp ound s having
sulph ur di oxide is same mole cular formula th.
(Van adiu m Pent aoxide / Iron) diffe rent struc tural formula. ~
(2) The prod uct form ed when ferro us
(C) A, B and C are the chemical propen:
sulph ate react with amm oniu m . ac1'd
of sulp huric •1.1es
:
hydroxide is _ _ _. (Ferrous
(a) Oxidizing agen t
hydroxide / Ferrous amm oniu m
(b) Dehy drati ng agen t
sulph ate) [2]
(c) Non volat ile acid
(C) Nam e the following organ ic compound:
(1) KCL + H2S04 ➔ KHS04 + HCl
(1) The comp ound with 3 carbo n
(2) CuS0 4.5H2 0 + H2S04 ➔ Cuso
atom s whos e funct ional grou p is a 4
aldeh yde. + 5H 2o
(2) The first homo logue whos e gene ral (3) S + 2H2S04 ➔ 3S02 + 2H20 [3]
form ula is CnH2n+1 OH
(3) The comp ound form ed by ethen e (D) Stud y and comp lete the following table:
react with hydr ogen in prescence
of Ni catal yst. [3]
:/:'t Ge~eralFormula
(D) Nam e the following: Bond type (a)
(1) Solv ent for noble meta l. First member of homo - (b)
(2) Drying agen t for HCl gas. Logue

(3) Solv ent for Silver chloride. IUPAC name of first , (c)
[3] member

[3]

Sca n QR cod e to dow nlo ad

solu tion s of this pap er

512 CE, Educ:'art

0

ICSE Che mis try Class X

r

ICSE
SAMPL E PAPER
(SEM ESTER-2)
SELF ASSESSMENT

CHEM ISTRY
nmeAllowed: One and a half hours
Maximum Marks: 40

SECTION - A [10 mark]

(Attempt All_th~ questions)

1, Choose the correct answers to the questions (F) The molecular mass of ammonia is:
from the given options: (a) 7 (b) 14
(A) The sixth homologue of alkane series is (c) 28 (d) 17
(G) The mixture of Cone. Nitric acid & Cone.
(a) Pentane (b) Ethane
HCl (1:3) is known as:
(c) Hexane (d) Pent-2-ene (a) Aqua fortis
(B) The prefix used for alkyne series is: (b) Aqua regia
(c) Oil of vitriol
(a) yne (b) ene
(d) None of these
(c) ane (d) - hydroxy (H) Which one of the following is dibasic
(q Galena is an ore of: acid:
(a) Aluminium (b) Zinc (a) Sulphuric acid
(c) Carbon (d) Lead (b) Nitric acid
(c) Hydrochloric acid
(D} Which acid is known as "Aqua Fortis"?
(d) Formic acid
(a) Nitric Acid
(I) Sulphide ores are concentrated by:
(b) Sulphuric avid
(a) Froth floatation process
(c) Acetic acid (b) Magnetit separation method
(d) Formic acid (c) Bc:ieyer's process
(E) The reaction in which organic compound (d) Hydraulic washing
react with oxygen to give carbon di The IUPAC name of Formic acid is:
(J)
oxide and water is known as:
(a) Acetic acid
(a) Combustion
(b) methanol
(b) Hydrogenation (c) methanoic acid
(c) Oxidation (d) Ethanol
(d) Reduction
0

fFI!_
Sample Paper 5 1::::!111
513
 SECTION - B [30 mark]
this Section)
(Attempt any three questions from
(B) Write a use of followin g alloys:
2. (A) Define:
(1) Bronze
(1) Gangue
[2] (2) Brass [2]
(2) Combustion

(B) Name the compound formed when: (C) Identify t he terms for the following:
(1) ethane reacts with oxygen (1) The electrode which have negative
(2) Sodium sulphite is heated wit h diL charge on it.
H2S04 [2] (2) Process to manufacture nitric acid
on industrial level
(C) Draw the struct ural diagram of:
(1) Propan-1-ol (3) An indicator which converts to blue
(2) Ethanal in colour when comes contact to
~ ) ~n~ar ~] sulphuric acid [3]

(D) Complete & balance the following (D) Complete the table given below:
reactions:
(1) C2Hs + Cl2 ~ Indicator I Real Colour Effect of acid
(2) C2H4 + HCl ~ '
Blue Red
(3) C + cone. H2S04 ~ [3]
- (1) ____________ .,_...
Phenolphthalein Colourless (2)
-
3. (A) Identify the anion present in the Methyl orange Orange (3)
1
following compounds:
(1) Compound A which on reacting with [3]
dilute sulphuric acid liberates a gas
which has no effect on acidified 5. (A) Name the ore and give formula of the
potassium dichromate but turns lead ores of following elements:
acetate paper black. (1) Lead
(2) Compound B which evolve a gas
(2) Aluminium [2]
having odour of burning sulphur. [2]
(B) Select the correct answer from the
(B) State the following:
brackets to complete the following
(1) The common name of carbamide
statements:
(2) Products formed when ammonia
reacts with sulphuric acid [2] (1) The acid anhydride of sulphuric
acid is ................ (Sulphur tri oxide /
(C) State the observation for the following: Sulphur di oxide)
(1) Ammonium nitrate is heated
(2) Ammonium nitrate is used in
(2) Calcium oxide react with HCl gas
preparing ............... (Explosives /
(3) BaCl2 react with sulphuric acid [3] [2]
refrigerant)
{D) Write balanced equation for the
(C) Name the following organic compound:
following conversions:
(1) Bromine gas from Hydrogen (1) The compound formed by
bromide & sulphuric acid hydrogenation of ethene.
(2) Nitrogen from ammonia & copper (2) The first homologue whose general
oxide formula is CnHln
(3) Silver chloride from silver nitrate & (3) The compound which is position
Hydrochloric acid [3] isomer to but-1-ene. [31

4. (A) Differentiate between following: (D) Name the following:

(1) Flux & Slag. (l) Catalyst used in hydrogenation of
(2) Calcination & Roasting. [2] unsaturated hydrocarbon.

0
r ... _._ -
 (2) Ga s Which .
col our . is red dis h bro wn in
(3) Wh ite prec·ip't (2) Wh at are the two nec ess ary
sul pha te sal ts. 1 ate ~•orrned conditions for the direct combin
by ation
(A) Dis ting uis h bet we en th [3] of S0 2 and chlorine form
6, ing
efo llow in9 . sulphuryl chloride.
(1) Alkene & Alleyne
• (3) Sta te the property of
(2) Blue & red Utrnus S02 which
cau ses KMn0 4 to cha nge its colo
[2] ur
(B) Give one wo rd from purple to colourless.
for the [3)
sta tem ent s:
following (D) Study and ~omplete the
following table:
(1) The gas pro duc ed wh
. .
hy d rox1de rea ct wit h en calc1urn
.
,,
, General F6rmula
,, -,,-,-, - -- -
chlor,'d e. arnrnoniurn , CnH2n+10H '
f
- !
Functional Group (1)
I
I

(2) The gas evo lve d wh en dil.

'd. sulph .
ac1 1s a dded to sod ium sulp uric First member of homo- (2) I
hite . logue I

I
[2] i
(C) Name the foll ow ing : IUPAC name of first l
(3) I

(1) Name the aci d for me d

member
wh en sul phu r \
di oxide dis sol ves in wa ter.
(3]

~
Scan QR co de to do wn loa d
so lut ion s of thi s pa pe r

sa mp le pa fff 515
 SOLUTIONS
SAMPLE PAPER–4

SECTION - A
1. (A) (d) Pent-2-ene (F) (a) Sulphuric acid
Explanation: Pent-2-ene is a position Explanation: When oleum is dissolved in
isomer of Pent-1-ene. water it get reacts with it to give sulphuric
acid.
(B) (d) – hydroxy
(G) (b) Nitrogen di oxide
Explanation: The alcohol group is
represented by OH. The prefix used for this Explanation: Nitrogen dioxide gas is
group is hydroxy while suffix used is ol. brown in colour. The yellow colour of nitric
acid is due to the same gas.
(C) (a) Aluminium
(H) (a) Ammonium nitrate
Explanation: Cryolite is an ore of
Aluminium having formula Na3AlF6 Explanation: HNO3 + NH3 ® NH4NO3
(D) (b) Sulphuric acid (I) (c) Baeyer’s process
Explanation: Because of its direct and Explanation: The ore of oxide is Bauxite
indirect applications in the manufacture of which is concentrated by chemical method
many chemicals including fertilizers. that is leaching.
(E) (a) Alkane (J) (d) Ethanal
Explanation: The all four valency of Explanation: Acetaldehyde has the

carbon is satisfied by single bond only. formula CH3CHO. It has two carbon atom
Hence it gives substitution reaction only. along with aldehyde group. Hence, it is
named as ethanal.

SECTION - B
2. (A) (1) Slag: Flux combines with the gangue to (3) 2-methylprop-1-ene: Prop means three
form a fusible mass called slag. carbon atom while 1-ene means double
bond at first carbon while 2-methyl
(2) Homologous series: It is a group of means CH3 attached on second carbon.
organic compounds having a similar
structure and similar chemical properties CH3 — C — CH2
in which the successive compounds |
differ by CH2 group and molecular mass CH3
14.
(D) (1) C2H2 + 2H2 ® C2H6
(B) (1) Carbon di Oxide and Water (CH4 + 2O2 (2) C2H4 + Cl2 ® C2H4Cl2
® CO2 + 2H2O )
(3) 2NH4OH + PbSO4 ® (NH4)2SO4
(2) Carbon di oxide and calcium oxide is + Pb(OH)2
formed . (CaCO3 ® CaO + CO2)
3. (A) (1)
Carbonate ion (It releases carbon di
(C) (1) Prop-1- yne: Prop means three carbon oxide gas which turns lime water milky.
and 1-yne means triple bond is present Hence it have carbonate as anion)
on first carbon atom. Hence the structure (2) Nitrate ion (It release in production of
is: CH3 — C º CH nitrogen di oxide gas)
(2) 3-hexene: Hex means six carbon and 3- (2) (1) These fumes are of ammonium chloride
ene means double bond is present at 3 (NH3 + HCl ® NH4Cl)
carbon atom.
(2) Reddish brown precipitate of Ferric
CH3 — CH2 — CH — CH — CH2 — CH3 hydroxide (FeCl3 + 3NH4OH ® Fe(OH)3 +

Chemistry Sample Paper 4 1

 NH4Cl) (2) Ferrous hydroxide
(3) (1) A gas evolved with brisk effervescence (C) (1) CH3CH2CHO (3 carbon means prop
which converts lime water milky. word root along with CHO group, Hence,
(Na2CO3 + 2HCl ® 2NaCl + H2O + CO2) named as propanal.)
(2) Yellow lead oxide converts into greyish in (2) CH3OH (First homologue means
colour. compound having one carbon, Hence,
(3PbO + 2NH3 ® 3Pb + 3H2O + N2) named as methanol)
(3) Blue vitriol gets converted into white in (3) Ethane (C2H4 + H2 ® C2H6)
colour. (D) (1) Aqua regia
(CuSO4. 5H2O + Conc. H2SO4 ® CuSO4
(2) Conc. sulphuric acid
+ 5H2O)
(3) Ammonium hydroxide
(D) (1) CuO + H2SO4 ® CuSO4 + H2O
6. (A) (1) Dil. HCl and get react with AgNO3 to
(2) NH3 + 3Cl2 ® 3HCl + NCl3 form white precipitate of silver chloride
(3) CaCO3 + 2HCl ® CaCl2 + H2O + CO2 which is soluble in excess. While Nitric
acid do not react with silver nitrate
4. (A) (1) Al+3 + 3e– ® Al
solution
(2) As they get oxidised to CO2
(2) Dil. HCl and get react with AgNO3 to
(B) (3) Magnalium ( 90-95% Aluminium + 10- form white precipitate of silver chloride
5% Magnesium) which is soluble in excess. While
(4) Duralumin ( 95% Aluminium + 4% Copper sulphuric acid react with silver nitrate
+ .5% Magnesium + .5% Manganese) solution to give silver sulphate.

(C) (1) Cathode (Cathode is positive charge (B) (1) Copper oxide
electrode while anode is negatively (2)
Isomers (compound having similar
charge) molecular formula but different
structure is known as isomers and this
(2) Haber’s Process ( N2 + 3H2 ® 2NH3)
phenomenon is called isomerism)
(3) Blue litmus (Ammonia is a base , hence it
(C) (1) (c) Non- Volatile acid
convert it from blue to red)
(2) (b) dehydrating agent
(D) (1) Haber’s Process
(3) (a) Oxidizing agent
(2) Ammonia
(D) (1) Single (The general formula of CnH2n + 2
(3) Oleum and water belongs to alkane)
5. (A) (1) Zinc: Zinc blende (ZnS) , (2) CH4 (On putting the value n=1 in above
Calamine (ZnCO3) formula we get CH4)
(2) Iron: Haematite (Fe2O3) (3) Methane ( For 1 carbon we use word
root meth and suffix ane will be added
(B) (1) Vanadium Pentaoxide
as it is alkane).

2 ICSE Chemistry Class X

 SOLUTIONS
SAMPLE PAPER–5

SECTION - A
1. (A) (d) Pent-2-ene (F) (d) 17
Explanation: The general formula of alkane Explanation: Ammonia have the molecular
is CnH2n+. On putting n=6, the formula will formula NH3. The molecular mass will be:
be C6H14. Due to 6 carbon atom word root 1 × (14) + 3 × (1) = 17
hex will be used and name will be Hexane. (G) (b) Aqua regia
(B) (a) yne Explanation: Aqua regia is the strongest
Explanation: Alkynes are the hydrocarbons acid mixture.
having general formula CnH2n–2. In this (H) (a) Sulphuric acid
the valency of carbon is satisfied by triple Explanation: Sulphuric acid looses two
bond. hydrogen ion. Hence, it is dibasic acid
(C) (d) Lead (I) (a) Froth floatation process
Explanation: The formula of Galena is PbS. Explanation: Sulphide ore such as galena,
And it is the ore of lead. zinc blende are concentrated by froth
(D) (a) Nitric Acid flotation process.
Explanation: Nitric acid is also known as (J) (c) methanoic acid
aqua fortis which means strong water. Explanation: The formula of formic acid
(E) (a) Combustion is HCOOH. It have one carbon hence
Explanation: During combustion organic word root hex will be used while due to
compound react with water and get prescence of COOH group oic acid will be
converted into carbon di oxide and water. added as a suffix. Hence IUPAC name will
be methanoic acid.

SECTION - B
2. (A) (1) Gangue: The impurities present in ore (2) Ethanal: CH3 — CHO
even after concentration is known as (The word root is eth which means two
Gangue. carbon atom and al means aldehyde
(2) Combustion: The conversion of organic group. Hence Its name is ethanal.)
compound into CO2 and H2O , when it is (3) Vinegar: CH3 — COOH
burnt with air, is known as combustion. (The IUPAC name of vinegar is ethanoic
CH4 + 2O2 ® CO2 + 2H2O acid. The word root is eth which means
(B) (1) Carbon di oxide and water two carbon atom and oic acid means
carboxylic acid group. )
2C2H6 + 7O2 ® 4CO2 + 6H2O
(D) (1) C2H6 + 6Cl2 ® C2Cl6 + 6HCl
(2) Sulphur di oxide is produced
Na2SO3 + H2SO4 ® Na2SO4 + H2O + (1) C2H4 + HCl ® C2H5Cl
SO2 (2) C + 2H2SO4 ® CO2 + 2H2O + 2SO2
(C) (1) Propan-1-ol 3. (A) (1)
Sulphide ion (The gas evolved is
CH3 ® CH2 ® CH2OH H2S. When it comes contact to lead
(The word root is prop which means acetate paper, lead sulphide is formed.
three carbon atom and 1-ol means OH (CH3COO)2 Pb + H2S ® 2CH3COOH +
group present at 1 carbon) 2PbS)

Chemistry Sample Paper 5 3

 (2) Sulphite ion (The gas produced by (2) Ostwald Process
sulphite ion compounds is sulphur di (3) Litmus
oxide which have a odour of burning
sulphur.) (D) (1) Litmus

(D) (1) Urea ( The another name of carbamide (2) Remains colourless
is urea having formula NH2CONH2. Urea (3) Pink
was the first organic compound formed
5. (A) (1) Lead: Galena (PbS)
in lab)
(2) Aluminium: Bauxite (Al2O3.2H2O )
(2) Ammonium sulphate (2NH3 + H2SO4 ®
(NH3)2SO4) (B) (1) Sulphur trioxide (When H2SO4 leaves
water molecule, it release SO3)
(C) (1) When ammonium nitrate is heated it
decomposes explosively leaving no (2) Explosive ( Ammonium nitrate results in
formation of N2O & water)
population behind.
NH4NO3 ® N2O + 2H2O (C) (1) Ethane (Ethene react with hydrogen to
give ethane)
(2) Calcium chloride will be formed
(2) Ethene (The first member of alkene start
(CaO + 2HCl ® CaCl2 + H2O)
from two carbon)
(3) White precipitate is formed (3) But-2-ene
(BaCl2 + H2SO4 ® BaSO4 + 2HCl)
(D) (1) Nickel
(D) (1) 2HBr + H2SO4 ® Br2 + 2H2O + SO2
(2) Nitrogen di oxide
(2) 2NH3 + 3CuO ® 3Cu + 3H2O + N2
(3) Barium sulphate
(3) AgNO3 + HCl ® AgCl + HNO3
6. (A) (1) Alkenes are the hydrocarbon in which
4. (A) (1) Flux is a substance which we add to the valency of carbon is satisfied by
molten metal to bond with impurities double bond. While in alkenes the
that can be removed afterwards, slag valency of carbon is satisfied by triple
is a waste material which is removed. bond.
Fluxes are used during refining of metals (2) Acid converts blue litmus red while base
and slag is impure residue converts red litmus to white.
(2) Calcination is a process where the air (B) (1) Ammonia (NH4Cl + Ca(OH)2 ® CaCl2 +
might be supplied in limited quantity, NH3 + H2O)
or the ore is heated in the absence of (2) Sulphur di oxide (Na2SO3 + H2SO4 +
air. It is done for carbonate ores. While Na2SO4 + H2O + SO2)
roasting includes heating of ore lower
than its melting point in the presence of
(C) (1) Sulphurous acid
oxygen or air. It is done for sulphide ores. (2) Sunlight and absence of moisture
(B) (1) Bronze: It is used in making medals , (3) Reducing
statues etc. (D) (1) Alcohal
(2) Brass: It is used in making screws & (2) CH3OH
handles.
(3) Methanol
(C) (1) Cathode

4 ICSE Chemistry Class X