Bansal Classes Organic Chemistry
Bansal Classes Organic Chemistry
Bansal Classes Organic Chemistry
XII (ALL)
QUESTION BANK ON
ACIDITY. BASICITY. H-BONDING & TAUTOMERISM Q. 1 (a) (b) (c) Write equations showing the Lewis acid-base reaction that takes place when Methyl alcohol reacts with BF3. Methyl chloride reacts with AICI3. Dimethyl ether reacts with BF3. Which of the following are lewis acids & which are lewis bases? CH3 (a) CH 3 CH 2 -N-CH : CH3
(d) :Brf
(C)(C6H5)3P:
(f) m
^/C?. 3 ' ,Jb) Jt) Q. 4 (a) (b) (c) (d) (e) (f) (g) Q.5
Which would you expect to be the stronger acid? Explain your reasoning in each instance. CH2C1C02H or CHC^CO.H CC13C02H or CHC12C02H CH2FC02H or CH2FCH2C02H Write equations for the acid base reaction that would occur when each of the following compounds or solution are mixed. In each case label the stronger acid & stronger base,& the weaker acid & weaker base. NaH is added to CH3OH NaNH2is added to CH3CH2OH Gaseous NH3 is added to ethyl lithium in hexane NH4C1 is added to NaNH2 in liq. NH3 (CH3)3CONa is added to H 2 0 NaOH is added to (CH3)3 C-OH C2H5OH is added to a solution of HC = C~Na+ in liquid NHV CHjCHjMgBr + CH3C = CH >A+B
Choose the member of each of the following pairs of compunds that is likely to be the stronger base.
v
(a) NH 2 or NH3 o-
( Jb)
OH orH 2 0 O
J c ) O H or SH
Choose the member of each of the following pairs of compunds that is likely to be the weaker base. 2 H 2 0 or H30 (C) CI", SH v , (b) H2S, HS- S ~ J d ^ F - , OH~ MTV, CH3 J e ) HF, H 2 0, NH3 , OH- SH", SeH
[2]
Label the reactants in these acid - base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the recations. CH 3 O: +CH3-CI: ->CH, - ^ C H V + lC i r O +CH^-P-H H
CH3-O-CH3 CH 3
O II
+ :O-H>CH3 -O: H CH 3
:o:
(c)
H - C - H + :NH 3 IS M
->H-C=RH NH 3
(d)
(e)
(f)
Q. 9
CH 3 - C - CH 3 + HSO4
Predict the products of the following acidbase reactions. H 2 S0 4 + CH3COO- ^ Methyllithium (CH3Li) is often used as a base in organic reactions. Predict the products of the following acid - base reaction. CH3CH2 - O H + CH 3 - Li > What is the conjugate acid of CH3Li ? Would you expect CH3Li to be a strong base or a weak base ? Which reagent in each pair listed here would be the more reactive Nu in a protic solvent ? xJ$) CH 3 NH- or CH3NH2 (b) H 2 0 or H,0 CH 3 SH or CH 3 OH CH 3 0- or CH 3 COO ^ (d) y M CH 3 COO" or OH k) Ph 3 N or Ph 3 P NH 3 or NH4 H.S orHS" Each ofthese molecules is electrophile. Identify the electrophilic atom & draw a mechanism for reaction with a generalised nucleophile Nu", giving the product in each case. (a) F (b) Y (c) V [ Y J (d) CI - CI X (e) MeO OMe
Q.12
& Tautomerism
[3]
19
rol^Ta
^bf. CH 2 = C H - C H = C H - C H 2 " or 0 Jtf 0 0 or
OH
CH^CH-CIV 0
0--C-C-0H
OH
II
II
HO-C-C-OH
II II
j *
Q. 20
( o r *
[or"
[OJ
(i)
[or
(ii)
NH2
L O
* (iii) NHt
NO,
(iv)
for
(i)
NH2
"
L Q
CH3
(ii)
(iii)
(iv)
(c>
(i) (ii) (iii) Dimethyl furmamide (DMF) is an example of polar aprotic solvent, aprotic meaning it has no hydrogen atoms attached to highly electronegative atoms. Draw what you predict to be its most important resonance forms. DMF when used as the reaction solvent, greatly enhances the reactivity of nucleophiles. e.g. NaCN + CH 3 CH 2 Br > CH^CIi, C = N + NaBr Suggest an explanation for this effects. Arrange the basic strength of the following compounds, OHft CHeC" (i) CH2 = C H C R j N R , 0) CH3COO(ii) CH 2 = CH(H) CT^CI^CI^ML, Oi) Gi(iii) CH3CIV (iii) CH = C - C i ^ W ^ d)
Q. 21 (a) (b)
[5]
Q.13 Each of these molecules is nucleophile. Identify the nucleophilic atom & draw a mechanism for reaction with a generalised electrophile E+, giving the product in each case. WR-C.COMe I
X INH T
(ONH.-NH,
( d ) M e O / ^OMe
(e)
^ M e
^,-Q. 14 Arrange the following compounds in order of increasing basicity. ^ x&f" yjdf CH3NH2, CH3 NH, CH3NH CH 3 0- CH3NH-, CH3CH2 CH3CH = CH", CH3CH2 CH2 , CH3C=C
Q.15 Neither of these methods of making pentan-1,4 diol will work. Explain why not-what will happen instead? (i) CH0-CH 2 -CH 2 -CH 2 -0H MeM
followed by H +
OH
C H 3 - C H - C H 2 - C H 2 -CH 2 I I OH OH Q 16 Suggest what species would be formed by each of the following combinations: (a) PhO - + CH3COOH ( b ) H N ^ N H + CH 3 COO(c) Pyridinium ion+trifluoroacetate ion Q.17 (i) (ii) Say which pka belong to which functional group in case of following amino acids: ^COOH cysteine: HS J : 1.8,8.3 & 10.8
NH2
glutamic acid : H 0 2 C \ ^ \ ^ C O O H . 2
NH2
]9>
4 25, 9.67
Record the following sets of compounds according to increasing pKa ( = - log Ka)
OH OH
C ^ J ' (^OJ ' cyclhexane carboxylic acid. 1-butyne, 1-butene, butane Propanoic acid, 3-bromopropanoic acid, 2-nitropropanoic acid Phenol, o-nitrophenol, o-cresol Hexylamine, aniline, methylamine Q. Bank on Acidity, Basicity, H-Bonding & Tautomerism [5'5]
NH 2
NH-C 6 H 5
NH 2
L O
(i)
(ii)
NH,
(iii)
NH,
V^O
fO
(i)
o
(ii)
CI
(iii)
ci(i) Q.23
RCOO(ii)
0H(iii)
RO(iv)
NH 2 -
(v)
ff
^NH
NH
[In aqeous medium]
J
h' (iii)
-NH2
NH
J*
Q.24
Arrange the following in increasing acid strength:
(a)
(i)
OH
=o
OH
T-C-CH,
O f o
(iii)
OH
O,
(i)
CH 3 - OH
CN
(ii)
(iii) O O
O
CH3-C-OH
0
HO-C-CH2CH2
(iii)
H0-C-C-0H
(ii)
J-
OH
[6]
v yO .25
jffi
{
Set the following in increasing order of pka: Methane sulfonic acid, acetic acid & methanol. CH 3 - CH2 - CH 3 , CH2 = CH - CH3 , CH3 - CHO , CHO - C H j - CHO , CH4 CH3N02,(N02)2-CH2,(N02)3-CH
OH nu 9H OH 9H X.
Ui)
^Jfy
ho2
^J y )
o
. . CN CN
^
H H
Q-Q-J&
H H
H
CN
^ fafff
Q. 26 (a) (b)
i
Cyanic acid (HO-CsN) & isocyanic acid (H-N=C=0) differ in the positions of their electrons but their structure do not represent resonance structures. Explain Loss of a proton from cyanic acid yields the same anion as that obtained by loss of a proton from isocyanic acid. Explain. > PhCH=CH-Br + C0 2
Q.28 Arrange the increasing order of acidic strength ofthe following compounds.
v>r ^
CH,
rb
(ii) CH 2 =CH-CH 2 C0 2 H () CF3OH (ii)
Col,
(iii) CH^CO.H <*) CCI3-OH (iii) [7]
(i)
CH 2 C0 2 H
(b)
x-(29
Explain which is a stronger acid. O O CH3 - C - CH3 & CH3 - C - CH2CN O . H ^ C O ) OCC 3 =~H S H or ' O H Jd)(0 O=C-CH3
CH3
^ a ) C 3 H BrCt^NO,, HC 3
Mo) <* ( O )
^jaf.5 0 Which ofthe following would you predict to be the stronger acid ?
^Jb) ^Jc)
CH3 - CH2 - CH2 - OH or GH3 - CH = CH - OH CH3 - CH = CH - CHj - OH or CH3 - CH = CH - OH Which is a stronger base? & Why. ethylamine or aniline yj^phenoxide ion or ethoxide ion (b) ethylamine or ethoxide ion \J<) cyclohexylamine or aniline
Calculate the pKa of phenyiacetic acid and the Ka ofpropionic acid. Which of these is the stronger acid? Predict whether the following equilibrium will favor the reactants or the products. < Q - C H 2 C O O +CH3CH2COOH < ^ y ~ C H 2 C O O H + CH3CH2COO
Q. 3 3 Explain why the 2-methylpyrrolidine boils at a higher temperature than its isomers N- methylpyrrolidine.
U- UneO'l
Q. 3 4 Although nitration usually causes elevation of B .P. yet the nitration of resorcinol to 2-nitroresorcinol decreases their B. P. then their parent compound. 5 o-nitrophenol is sparingly soluble in water & has lower B .P. but p-nitrophenol is completely soluble in water & has high boiling point. 6 When 3 0 ml of ethanol and 5 ml of water are mixed the volume of the resulting solution is less than 35 ml. Explain. <f| Bansal Classes Q. Bank on Acidity, Basicity, H-Bonding & Tautomerism [8'5]
^ Ammonium salts are much more soluble in water than are the corresponding sodium salts. Explain? QS 8 HF has a dipole moment of 1.82 D, its boiling point is 19.34C. Ethyl fluoride has an almost identical diploe moment & has a larger molecular weight, yet its B.P. is -31.TC. Explain. J&39 HC02H & CH3C02H exists as dimer. Explain. Q. 40 Cyclohexanol is more soluble in water then 1 -hexanol. Q. 41 Explain why CH3OH and CH3CI^OH are reasonably good solvents for many ionic compounds compare the solvent properties of ethanol and pentanol towards ionic compound. Q.42 \J#A3 J^45 1,5-Pentanediol is soluble & 1-Pentanol is slightly soluble in I^O. Compare the relativ^i^ oiling points Water solubilities oftoluene & phenol.
Q.44 Which isomer (o,m or p) ofhydroxacetophenone steam distills. Give structure for ethanolamine showing two different intramolecular H-bonds & discuss their relative strength. f O (a) o ^ = M r v > 0 OK v o
W W
Q.46 Which ofthe following system show H-bonding during tautomerism. N-H (c) A ( d ) ( \
(b) ..
H HoXr NC^H HOaH Q. 47 Trans isomer ofindigotin is stable w.r.t cis isomer. Explain.
A
Q. 4 8 What is the attacking site of conjugate base oftriketo form ofphloroglucinol in protic & aprotic solvent. \JQC49 In each ofthe^ollowing pairs which is more stable:
H (I)
(11)
O
C /
0 H
O
C /OH
(I)
0
C
u
(nf
C 3
(J^NH
0 H
(11)
[9'5]
C
(I)
/OH
U)
/OH
(ID
(11)
(I)
/
(II)
0 H
0 II (e) a / V
3
0 I!
N
3 3
a)
CH3 - cuf V
crH
c
O
ao
X c
O H ^CH2
o f
c
o
N
c
(II)
CH3
O
0C__^0
fj
CH,
L,
j 0
(ii)
^ v o
(1)
w
CH
(II)
y CH2
CH,
g
(IT)
CH
(1)
OH
...
O O H O O H
(II)
d#52
'
O
Ph Ph
(II)
O^
Ph
^H
(I)
Ph
^0
(I)
O H
(II)
Bansal Classes
[10]
Q. 53
In each ofthe following pairs which will have higher enol content:
O ^COOEt ft
/
CH 3
\
CH 3 ft ft
(b) C \
and
C O O Et CH 3 CH 3
(c) C \
.
v
and
COO Et FL CH 3 FF CH 2 " FL OCH 3 ' FL
and
CH 3 0 CH 2 CH 3 0
/
CH 3
\
CH 2
/ II
0
\
OCH 3
II
CH 2
II
CH 3
II
CH 2
(e) Q. 54 ^
CH 3
and
Ph
Ph
In each ofthe following pairs which will have less enol content: C ^ V V ( b ) C T a n d Q
and Q
^ ( ^ f
and
Q. 5 5 In each ofthe following pairs which will have higher enol content: (b) (qY \
c
II
r
CH 2 - C H O and CH 2 - C H O
I I
and
3 CH 3
y\
O 11
CH 3
NO 2
CI
0
v
0
CH 2
> 0
CH 3
CH 3
j and
CH 3
c / \
r
CH ^2H5
CH 3
( Bansal Classes
[11]
In each of the following pairs which will have less enol content:
\ /OCH3 V / O C H
:
(a)
0
0
^ 0
andCP
-"Sr
J d ) h > = 0 and h > 0
O ^ C P
r. TjJ^
H
and
^ ^ o
H
57 Which ofthe following compounds can exhibit tautoimerism: (a) CHj = C = O (b)CH2 = C H - 0 H (c)HO-CH = CH-OH (d) CH3CN (e)
C
^NO2
II o
(d)(6r0^
(e)@rH
NH
^
OMe
(d) Ol
I OJ
(e) CH3 - NO
61 what is the relationship between these two molecules? Discuss the structure of the anion that would be formed by the deprotonation of each compound.
1 1
<f| Bansal Classes
->A I
H
JL
N5" "OH
[12'5]
Q. 62 5,5 - dimethylcyclohexane -1,3 -dione (dimedone) shows tautomerism.Write down tautomeric structure. Q. 63 Draw enol forms of these carbonyl compounds and comment on the stability of the enol forms. (a) "
o
O
4x
>oo
o O
(b) ( ^ J ^
Q. 64 The proportion of enol in a sample of the two ketones below are shown. Why are they so different ? % enol
C H B O ^ ^ - X ^ M I - CH = CH 2
Q.65 (a)
Jf
and
J
CH = CH 2
< CU
Q. 66
Shows tautomeric forms of (a) & (b). Isatin was thefirstcompound to show tautomerism.
e x "? : N
H What is the tautomeric form ofisatin. Q. 67 1 , 3 - dicarbonyl compounds such as (A) are usually mostly enolized. Why is this ? Draw the enols available to compounds A & B comment on the different pattern of enolization.
I
Q. 6 8 In each of the following sets of compounds write the increasing order of % enol content
JSC
(0 (I) (I)
<TI>
6
(HI)
A
(IV)
N 0
(gong;
(11) 2 O2N
, n m i
(IIJ)
NO 2
[13'5]
(C)
(grv
(1) NO,
^
(LI)
o
(111)
o
NO 2
(II)
(111)
NO,
CI u^LQj o O
(11)
Ct
o
(III)
Q. 69
In each of the following sets of compounds write the decreasing order of % enol content.
O
(a)
0(I)
(i)
CO (II)
(II)
(SQ
ail)
o
(III)
(IV)
j a) y
o
(d)
o (11)
(III)
cNr
(IV)
j y
(ii)
o
(HI)
(HI)
(1)
N" H
o.
(IV)
o
(e)
o a)
(II)
O
(TV)
( S | Bansal Classes
[14]
Q. 70 Enol form of cyclobutanone is very unstable vs enol form of triketocyclobutane, which is very stable.
Q.71
O
A
Q-72 CH{
N
O
A
CH3 CD3/
X
a
CD3 CH 3 \ N
(i)
y do
(in)
CH3
Among these give ease of enolization. Q. 73 % enol content of acetylacetone in following solvents is found as: Solvent % enol content HjO 15 Liquid state 76 hexane 92 92 Explain the observation. Q.74 J k ^ ?
(Minor)
@ @
(Major)
Na0Hl[,H20 O
OH (Major)
OH (Minor)
O H
This tautomeric system exist almost exclusively in favour of phenol and it is insensitive to change in solvent.
[1'5]
ANSWER KEY
Q.2 Q.3
Q.5
Q.6 Q.7 Q. 11 Q.14 Q.18 Q.19 Q.20 Q.22 Q.23 Q.24 Q 25 Q.28 Q.29 Q.30 Q.31 Q.32 Q.49 Q.50 Q.51 Q.52 Q.53 Q.54 Q.55 Q.56 Q.57 Q.58 Q.59 Q.60 Q.68 Q.69 Q.72
(a) 1; (b) 1; (c) 1; (d) 1; (e) 2; (f) 1 (a) 2; (b) 1; (c) 1; (d) 1; (e) 1; (f) 3 (a) 1; (b) 1; (c) 1; (d) 1; (e) 2; (f) 2; (g) 2; (h) 1 (a) 2<1<3; (b) 1<2<3; (c) 3<1<2 (a) 3<2<1; (b) 1<2<3; (c) 3<2<1; (d) 2<1<3; (e) 2<3<1 (a) 2; (b) 1; (c) 2; (d) 2 (a) 3<2<1<4; (b) 1<2<3<4; (c) 3<1<2 (a) 1>2>3; (b) 1<2<3; (c) 3<1<2; (d) 2<1<3; (e) 1<2<3; (f) 1<2<3<4<5 (i) 1>2; (ii) 4>3>1>2; (iii) 1<2; (iv) 1<2 (a) 1<2<3; (b) 3>1>2; (c) 1<3<2 (i) 1<2<3; (ii) 1>5>2>3>4; (iii) 1>2>3; (iv) 1>3>4>2; (v) 1>3>2; (vi) 2>1>3; (vii) 3>4>2>1 (a) 3>1>2; (b) 1>2>3; (c) 2>3>1 (a) 2; (b) 2; (c) 1; (d) 1; (e) 1 (a) 2; (b) 2; (c) 2 (a) 1; (b) 2; (c) 2; (d) 1 4.25,1.34><10_5 (a) 2; (b) 2; (c) 1; (d) 1; (e) ^ (a)2; (b) 2; (c) 2; (d) 2; (e) 1 (a) 2; (b) 2; (c) 1; (d) 2; (e) 1 (a) 2; (b) 1; (c) 1; (d) 1 (a) 1; (b)l; (c) 2; (d)l; (e) 2 (a) 1; (b) 1; (c) 2; (d) 1; (e) 2 (a) 1; (b) 1; (c) 1; (d) 1 (a) 2; (b) 2; (c) 2; (d) 1; (e) 2 a, b, c, d, e a, c, d b b (a) 2>1>4>3; (b) 3>2>1; (c) 3>2>1; (d) 3>1>2; (e) 3>1>2 (a) 3>1>2; (b) 4>2>1>3; (c) 4>3>1>2; (d) 1>3>4>2; (e) 3>2>4>1 3>1>2
4g Bansal Classes
[16]
BANSALCLASSES
TARGET IITJEE 2007
i
ORGANIC CHEMISTRY
XII (ALL)
CONTENTS
EXERCISE-1(A) EXERCISE 1(B) EXERCISE-II EXERCISE-III EXRECISE - IV(A) EXRECISE - IV(B) ANSWER KEY
EXER CISE-IfA)
Q. 1 Which of the following reaction is called as 'Bouveault-Blanc reduction' (A) Reduction of acyl halide with HyPdBaSC^ (B) Reduction of ester with Na/C^OH (C) Reduction of anhydride with Li A1H4 (D) Reduction of carbonyl compounds with Na/HgHCl Glycol on treatment with PI3 mainly gives(A) Ethylene (B) Ethylene iodide (C) Ethyl iodide (D) Ethane (D) HN0 3 (D) Glyceric acid
Q.2 Q.3 Q. 4 Q. 5
Acrolein is formed when glycerol is heated with(A) Acidified KMn04 (B) Br2 water (C) KHS04 Glycerol on treatment with oxalic acid at 110C forms(A)Allyl alcohol (B) Formic acid (G) C0 2 and CO
If the starting material is 1-methyl-1,2-epoxy cyclopentane, of absolute configuration, decide which one compound correctly represent the product ofits reaction with sodium methoxide in methanol.
Q. 6
When phenol is treated with PC15, the yield of chlorobenzene is generally poor because ofthe formation of (A) Benzoyl chloride (B) p-chorophenol (C) o-chlorophenol (D)Triphenyl phosphate In the following reaction,finalproduct is
Q. 7
CICH2CH-CH.2
14
14
NaOC2H<
(A) CICH2CHCH2OC2H5
OH
(B) ClCH2CHCH2ONa
14
(C) CH2-CHCH2OC2H5
14
(D) CH2-CHCH2OC2H,
14
fe Bansal Classes
[13]
Q. 8
Which forms di-iodide on reaction with HI (excess)? (A) I and II both (B) II only (C) I only Q. 9
0
(D)none
Ethanol on reaction with acetic anhydride gives (A) Acetic ester (B) Formic ester (C) Ethanoic acid (D) Acetic ester and Ethanoic acid both
Q. 10 Ethanol cannot be dried by anhydrous CaCl, due to formation of the following solvated product (A) CaCI2-2C2H5OH (B) 2CaCl2-3C,H5OH (C) C a C l ^ C ^ O H (D) CaCl2-C2H5OH Q.ll Rate of hydration of
Q.13 The number of methoxy groups in a compound can be determined by treating it with (A) HI and AgNO, (B) Sodium carbonate (C) Sodium hydroxide (D) Acetic acid Q. 14 Most acidic alcohol out of following compounds is (A) (CH3)3C-OH (B)CH3CH2OH (C)CH3OH Q.15 Action ofHN0 2 on CH3NH2 gives following as major product (A) CH3OH "(B) CH 3 -0-CH 3 (C) CH 3 -0-N=0 (D)PhOH (D)CH 3 -N0 2
Q . 16 A compound 'X' with molecular formula C3HgO can be oxidised to a compound' Y' with the molecular formula C1H602, 'X' is most likely to be (A) Primary alcohol (B) Secondary alcohol (C) Aldehyde (D) Ketone Q.17 Diethyl ether and air gives ether hydroperoxide. The mechanism ofthe reaction is (A) Nucleophilic substitution (B) Free radical addition (C) Free radical substitution (D) None of the above Q.18 Ether on carbonylation gives (A) Alkanoic acid (B)Alkanone Q. 19 I0R - O- R i H (C)Alkylalkanoate (D)Alkanal
(A) SN1 in gas phase (C) both of the above Q 20 Phenol with Hinsberg's reagent gives (A) Sulphone (B) Sulphanilic acid fe Bansal Classes
(B) SN2 in aqueous phase (D) none (C) Sulphonic ester (D)Sulphonal [13]
0 .21
Select the odd structure out (A) CH 3 -CH(OH)-CH2 -CH 3 (C) CH3-CH(OH)-CH3
, KHSO, * LiAlH4
Q.22
Glycerol A A and B are : (A) Acrolein, ally! alcohol (C) Ally] alcohol, acrolein
(B) Glyceryl sulphate, acrylic acid (D) Only acrolein (B is not formed)
Q 23
An ether is heated with phosphorous penta sulphide to give (A)Alkanthiol (B) Dialkyl sulphide (C) Hydrogen sulphide (D)Thioester Phenol A
H+/H2
Q.24
(ii)C02/140C
>B
CH3COOH,A
In this reaction, the end product C is: (A) salicylaldehyde (B) salicylic acid Q.25
(D) aspirin
In the Liebermann's nitroso reaction changes in the colour of phenol occurs as: (A) Brown or red-greenish red-deep blue (B) red-deep blue-green (D) white-red-green (C) red-green-white
Q.26
CH2OH
7 r>cH3
Q.27 I^IJ
cold
>A
"
CrO,
ACOH
>B
alkaline K M N 0 4
(C)
CH3 OH OH '
fa Bansal
Classes
[36]
Q.28
B *
NaBH,
r v
CH = CH - CHO
H2/Pt
>A
/ - CH 2 CH 2 CH 2 OH,
CH, Q.29 B 4r
CH,OH CH,ONa
CH.-C-CH,
\J o
"
2 18
H+
>a
CH,
CH,
OH OH CH,
(C) CH 3 - C - C H , , CH, - C C H ,
IBOH OH
0OH 18
(D) C H , - C C H , , C H , - C CH,
3OH 18
OH
OH
OCH 3 OH
Q.30
Oxalic acid + A
>
henceA
^ B , B i s : 0 = ^
(A)
(B)
(C)CH2-0-CH2 OH OH
(D) None
fa Bansal
Classes
Alcohols
' CH2CH3
K
rH=PH_
0H
Q.31 CH2CH2OH
Select schemes A, B, C out of I acid catalysed hydration (A) I in all cases (B) I, II, III Q 32 Dehydration of the alcohols -OH
(I)
II
!IS
-OH OH (II) (B) I > II > III > IV OH (III) (C) IV > II > III > I (TV) (D) II > IV > I > III
Q 33
CI-LMgBr
Mg/ether
> r.
H,0+
F,
E is (A) CH3 OH
Et
(Q
Q.34
Me
Ox
/Et
(A)
Q 35
/ \ / \ /
CI
Ale. KOH
( ) \0/V^/ \ A
(C)
H
(B) H \ q A A
(D)
/ \ / \
CJ x r
[36]
fa B a n s a l
Classes
RMgX
Q.36
R' R"
R
H2O
? P r o d u c t Obtained is:
R (C)R'GH2-C-OH R"
R (D)R"CH2-C-OH
R'
(A)R'-C-CH2OH
R"
OH
R H
Q.37
CH,
I,/NAOH
H+
A )
A, A IS
. .
o II
o II
Cs
C-OH
(A)
<B>pr
(C)
(D)
~OCH,
Q.38
(A) <
CH3
H 2 SO 4
(A)
\H H.CO
CP 3 OH
&
\H OH
?PH3
ch
\H
(B)
yj(
Of
&
H HO
OCH, CH 3
H 3 CO
CH3
(C) H OH
&
MeO CH 3
CD)" H 3 CO
&
OH H 3 CO OH
Q.39
OCOCH3
AICI3
>
7 M a j o r P r o d u c t is:
(B) H 3 C O C
()\Or\Oy~OH
COCH,
<!Bansal Classes
O-CH2CH=CH2 Q.40 Y Q Y
A
, ^ ? Product is:
OH
OH
/R
(A) CH2CH=CH2 OH
R V A / R
R\/ (B)
/R
CH 2 -CH-CH 7
(c)
iJSiCH2CHCH9
OH
(i)CHCS3+KOH OH (ii)CH 2 I 2 +NaOH
(D) no reaction
Q.41
(A)
HOOC' ^
j c g f OH
X
OH
O H C
/
\ ^
O H
(D)
OHC
OCH3
Q.42
/OH OH
Inthisdiol
(A) OH at C2 is more basic than that of at C5 (B) OH at C2 is more acidic than at C5. (C) both have same basicity (D) both have same acidic strength Q.43 (CH3)2C = C(CH3)2 (A) (CH3)2C-C(CH3)2 O (C) (CH 3 ) 2 C-C(CH 3 ) 2 I I OH OH
OH CH 2 -NH,
H,O
0H
Q.44
| A is
NaNO, HCl
>A
OH (A)
CH-,-OH (B)
OH
CH2-C1
OH ( C ) f l
CH 2 -NO,
( D ) f S
i&Bansal Classes
fSJ
Q.45
Mn0
--
)A.Ais
HCO,H 2
> A
>B + C
PthalicAnhydride
K OPh
/OH
(A)CH3OH&(^Xc><J
(B)PhOH&[0 II 0
OH
K
C-
o II (D) CH 3 OH & [ O
C-CH3 C-CH3
V- lo
Q. 47
COOH H,
II o
m-Aminophenol on treatment with NaOH and C 0 2 gives which of the following as major product?
OH f ^ Y
(D)
H
(A)
OH
(B)
L J
COOH
(C)
XOOH
^Y^COOH
NH,
Question No 48 to 50 (3 questions)
500C No reaction LiAlH 4
NaBH,
COOH
Q.48
fa Bansal
Classes
[36]
Q. 49 Organic compound A does not undergo de carboxylation reaction because? (A) Intermediate does not follow Saytzeffn rule (B) Intermediate does not follow Hofmanris rule (C) Intermediate does not follow Bredict's rule (D) Intermediate does not follow MarkwoniKoffs rule Q. 50 Total No. of stereoisomers of B are? (A) 2 (B)4 (C)3 (D)6
EXERCJSE-I(B)
Q. 1 Compound which gives alcohol on reduction is/are (A) Me - C - CI (B) M e - C - N H , 0 0 (C) M e - C H - C H 2 II II (D) M e - C - O C - M e
I I O
Q.2
I " I o
Phenol and ethanol are distinguished by the reaction with (A) Red litmus (B) NaHCO, (C) FeCl3 In the reaction sequence, CaC2
H2
Q. 3
>A
' B
(A) give yellow ppt. with NaOI (B) itsfinaloxidation product is carbonyl compound (C) itsfinaloxidation product is C0 2 and H 2 0 (D) itsfinaloxidation product is CH3COOH Q.4 Which can be cleaved by HI0 4 ? 0 0 II II (A) CH3CH2CCH2CCH3 OHO I H (B) CH3CHCCH2CH3
(C)
y / , ( OH
, ,
'OH \qh
(D) CH3CCH2CHCH2CCH3
1 1
1 1
Q5
HBO, oxymercuration-demercuration and acid catalysed hydration will not give same product in (B)
(cO
(dO
Q. 6
Diethyl ether reacts with PCP5 to form (A) Ethyl chloride (C) Ethenol
fe Bansal Classes
[13]
Q.7
> (CH3)3CO-^o)
The molecules of ether dehydrates in the presence of(A)A1 2 0 3 (B)H 3 P0 4 (C)H2S 2 0 7 Anhydride of alcohol is (A) Ether (C) Alkyl hydrogen sulphere
(D) liq. NH 3
Q.9
Q. 10
anhydrous ZnCl 2
>
R C j
White turbidity
This shows that (A) ROH behaves as a base (B) greater the value of pKa (alcohol), greater the reactivity with conc. HC1 and thus sooner the formation ofwhite turbidity. (C) alcohol which reacts fastest with Na metal, will give turbidity at fastest rate (D) alcohol which gives red colour during Victor Mayor test, will give turbidity at slower rate then those giving blue or white colour during Victor Mayor test. Q. 11 If ethanol dissolves in water, then which of the following would be done (A) Absorption of heat (B) Emission of heat (C) Increase in volume (D) Contraction in volume Which method is useful for the synthesis of ether?
Q. 12
Which of the following can react with TsCl (A) Glycerol (C) Oil ofwintergreen
(!Bansal
Classes
[U]
(A)
/Urn H 0 T CH
CH;
CH 3
HS 4 2
3
CH3OH
rm
(DJ
\ , \ ~ ~ K/
CH;
CH,OH
H | O
CH 3
O
(D)
R-C^OH + HtO-R
"
H+
Q.15
3 -methyl-3 -hexanol can be prepared by (A) CH3MgI and 3-hexanone, followed by hydrolysis (B) C2H5MgI and 2-pentanone, followed by hydrolysis (C) C3H7MgI and 2-butananone, followed by hydrolysis (D) C4H9MgI and propanone, followed by hydrolysis
Q 16 In which cases product formed are not according to reaction? (A) ^ ^ - O H + HNO3 (B) ( ^ y ~
0 H
h
2s4
>
NO,
+HN0 3
2s4
Q-ONO.
(C) CH2 = CH-CHO + LiAlH4 -> CH3 CH,CH2OH (D) ~ Q.17 -Cl + CH3ONa >
-OCH
Dehydration of alcohols take place more rapidly with POCl3 than with H,S0 4 . Select the correct statement(s) about the following dehydration reaction.
Is.
j )
pyridine
(A) It does not involve carbocation. * (B) It involves R-OPOC1, with - OPOC1, as a better leaving group. (C) It involves E2 mechanism as pyridine base abstracts proton from the adjacent carbon as the same time at which - OPOCl2 is leaving. (D) It is E1 reaction without formation of carbocation. fa Bansal Classes Alcohols & Ethers [36]
Q.18 Which of the following will get oxidised by Br2 / KOH into carboxylic acid? (A) CH3-CH2-OH (B) CH - CH3 OH (C) ( ^ y - C H 2 O H (D) Q
S
CII,
<
Q. 19 In Kolbe-Schmidt reaction, o-hydroxy benzoic acid is predominantly formed. This is because (A) salicylate anion is a stronger base than phenoxide ion (B) salicylate anion is a weaker base than phenoxide ion (C) p-hydroxy benzoate ion is a stronger base than phenoxide ion (D) p-hydroxy benzoate ion is a stronger base than salicylate ion Q. 20 Methanol can be distinguished from ethanol by (A) Heating with I2 and alkali (B) Treating with schifFs reagent (C) Treating with Cr03 solution in dil. HjSO,^ (D) Treating with Lucas reagent Q.21 Products form by following reactions are A.
OH
CH, OH OH
OH CHO
C A ) ^
CH3
( B ) ^
c h o
(C) ^
CH3 CHO
.(D)
CH
CH3
Q .22 For the reactions shown below, identify the correct statements) with regard to the products formed:
(i)
ph
*>\y0
(h)
ph
^\7
(A) P and Q are identical (B) P is recemic and Q is optically active (C) P and Q are positional isomers (D)hoth are optically active Q.23 C,NSNH, (A) Alcohol
Tilden
reagent
> (i)
NH
? > (ii)
HC1
(iii). The product (iii) can be (C)Alkyl chloride (D) Alkyl nitrite
fe Bansal Classes
[13]
Q 24
(A)f Q. 25
(B)(
(C)|
(D)
cy
\>H
Select the correct statement(s) (A) It is more acidic than CH3OH (C) It reacts very fast with Lucas reagent Q. 2 6 Match the following: Reaction
OH
O (B) It is more acidic than CH 3 COH (D) It is a diacid base Mechanism (P) change in number of carbon in cycle
(A)
(B)
CH3CH3
OH
(Q)
Pinacol rearrangement
(C)
OH
heat
>
(R)
O-CH,
<P) Q. 27
(S)
Ketone as product
Match the column: Column I Identification of 1, 28c 3 Alcohols (A) Identification of 1, 2& 3 Nitro alkanes (B) Formation of alcohol by anti Markovnikov's (C) addition o f H 2 0 Formation of alcahol by Markovnikov's (D) addition
Column II Oxymercuration demercuration Cu/300 heat Victor Mayer's test Hydroboration oxidation Lucas test
& Bansal
Classes
[14]
Q.28
Match the column: Column I (A) Oxidation of 1 alcohol in aldehyde (B) Cr0 3 L U .HC1
(P) (Q)
N'
Cr0 3 .2
N
(R) (S)
Column II
^ 0 >
(?)
(Q)
(0>i
{ o >
CH
2 - OH
(C)
(R)
OH
(D)
f n l + K i > ?
(S)
<OVCH2-I
Q.30
CH, - CH - CH = CH 2
I
ReageatR^ Alcohol
Reagent B2H6,H202/Na0H
CH,
CH3-CH-CH^CH3 (B)
I OH I
CH 3 OH
PdCl2, H 2 0, 0 2 / LAH
(O
CH3--C-CH2CH3 CH 3
OH
(D)
CH3-C-CH2CH3 CH 3
dil. H2S0 4
fa Bansal
Classes
[36]
EXER Q. 1
CISE-II
What reagents could you use for the following conversions (a) MeC0(CH 2 ) 0 C0 2 Et -> MeCH0H(CH 2 ) 2 C0 2 Et
(b) H02C(CH2)4"C0Cr-> H02C-(CH2)4CH20H
0 2 N(CH 2 ) 2 CN -> 0 2 N(CH2) 2 CH 2 NH 2 0 2 N(CH 2 ) 2 CH = CH2 -> H2N(CH2)2CH=CH2 Me2CHCOCl -> Me 2 CHCHO 0 2 N(CH 2 ) 3 CH0 0 2 N(CH2) 3 CH 2 OH 0 2 N(CH 2 ),CH=CH 2 -> 0 2 N(CH 2 ) 3 CH 3
Following compounds undergoes reaction with Mn0 2 . What are the products in each case? (a) CH 3 CH 2 CH=CHCH20H (tyPhCI^OH (c) PhCH(OH)CH 2 CH 2 OH (d)MeCH=CH(CH 2 ) 3 OH (e) [ ^ > - O H
Q. 3
/ v
(iv) (v)
Q. 4
CI
-CH 2 OH Glyceraldehyde
in acidic and in basic medium. Q. 5 Find the structures ofA to F. C6H120 (A) mild
^ ^ C I L C O J I
Q.6
Q.7
R2C = O + Et3Al -> C 2 H 4 + R 2 CHO AlEt2 Suggest a mechanism for the reaction.
fa Bansal
Classes
[36]
D-S2-B
1.CHJCHO 2. HjO
Q. 9
Me2C. \
o-J
(i) (iv)
1.HCO3H 2.H20
Q. 10 What are the order of rates of oxidation with HI0 4 ofthe following diols. Explain with reasons. (a)Me 2 C(0H)C(0H)Me 2 (b) Me2C(OH)CH (OH) Me (c) CH2(OH) CH2 (OH) (d) Me CH(OH) CH (OH) Me Q. 11 t- Butanol in presence of fenton's reagent forms 2,5 dimethyl hexane 2,5 diol as one of the product. Explain with the mechanism. Q. 12 How you distinguish the following compounds? (a) t butyl alcohol & n butyl alcohol (b) ethyl alcohol & n propyl alcohol (c) allyl alcohol & n propyl alcohol (d) benzyl methyl ether & benzyl alcohol Q.13 Differentiate: (a) 1 -Hexanol and 1 -chlorohexane (c) Diethyl ether and n-pentane
Q.14 Explain: (a) No est erifi cation takes place between ethyl alcohol and excess of sulphuric acid at 170C. (b) Sodium chloride solution in water is added to decrease the solubility of organic compounds in water. Q.15 Predict A, B & C.
CH3OH P+L2
>A
+C
Q. 16 Carry out conversion of methyl alcohol into ethyl alcohol and vice versa. ^Bansal Classes Alcohols & Ethers
PV
Q.17
Arrange the compounds (i) Ethanol, propane and 1-pentanol, (ii) Butane 1,2,3-pentanetriol and butyl alcohol, (iii) Pentane, 1 -pentanol and 1 -hexanol, on the basis of (a) in order of increasing boiling points and (b) in order of increasing solubility in water.
Q.18 Complete the following equations & comment: (iii) Me2C = CH2 Q. 19 Complete the following equations: (i) n - C3H7 - C02H > n - C4H9OH (ii) (iii) (iv) Me2CO + EtMgl EtC02Et + 2MeMgI ^ ( /=CHCO,Et / /=CHC0 2 Et ?
H+
>?
pressure
>? >?
T T Mn0?
>?
Q. 20 t-butyl alcohol reacts less rapidly with metallic sodium than the primary alcohol. Explain why? Q. 21 Diethyl ether behaves as base. Why? Q. 22 What is the significance of proof spirit? Q. 23 Sodium metal can be used for drying diethyl ether but not for ethanol. Why? Q.24 Sometimes explosion occurs during distillation of ether sample. Give the reason.
Ag20
>B
Q. 27 Ethyl alcohol reacts with HI but not with HCN. Explain why? Q. 2 8 Write the structure ofthe principal organic product formed in the reaction of 1 -propanol with each of the following reagents: (i) Potassium dichromate (K2Cr207) in aqueous sulfuric acid, heat (ii) (iii) Acetic acid CHXOH in the presence of dissolved hydrogen chloride. CH3 y~S0 2 Cl in the presence of pyridine
0 II
OO
(iv) C6H5COCC6H5 in the presence of pyridine
fe Bansal Classes
[13]
o
(v)
m
Presence
pyridine
Q. 29 (a)
Complete the following series of equations by writing structural formula for compounds A through I: \\ ^ J j//
\\ //
HCl C
C H f1 5 H ? C J > S 7
NaHC
^
3 ) C H O
5 8
H2S04,H20
Compound B
SOC 2
pyridine
'
> C,H,,C1 ^
(ii)Zn/H20
NaB 4
"
>CH,,(
5 11
OH
(D)
(E)
(F)
(c)
^ ^ N ^ P H
* ' heat e.
> Compound G
' '
Compound H
CH,C1,
> Compound I
Q. 3 0
(a)
Predict the principal organic product of each of the following reactions. Specify stereochemistry where appropriate. /Br
methanol H;C
- ^ ( A )
(b)
|>
CH2C6H5
+ CH 3 ONa
CH3 H
>(B)
VCH-CH2
> (D)
Deduce the identify ofthe missing compounds in the following reaction sequences. Show stereochemistry in parts (b) through (d). CH2 = CHCH 2 Br
(iii)H,0
+
compound A(C4HgO)
compound C (C 4 H 7 BrO)
K0H H
^Bansal Classes
[19]
Choose the reaction in each ofthe following pairs that proceeds at the faster rate. Explain your reasoning. Base-promoted hydrolysis of phenyl acetate or m-nitrophenyl acetate Base-promoted hydrolysis of m-nitrophenyl acetate or p-nitrophenyl acetate Reaction of ethyl bromide with phenol or with the sodium salt of phenol. Reaction of ethylene oxide with the sodium salt of phenol or with the sodium salt of p-nitrophenol Bromination of phenol or phenyl actetate.
Q. 3 3 Explain why ArOR ethers are cleaved to give RI and ArOH rather than Arl and ROH. Q.34 Explain the mechanism of following:
(iii)
0 35 Outline a synthesis of each alcohol from the indicated starting materials: (a) Isopropyl alcohol from a hydrocarbon (b) n-butyl alcohol from acetylene (c) allyl alcoholfrompropane, and (d) t-butyl alcohol from t-butyl chloride Q.36 What product is expectedfromthe reaction of (f O with (a) LiAlH4 and (b) H^/Pt
Q.37 Give the product of the reaction ofPhjCHC^OH with HBr and explain its formation. Q.38 Give the product and write a mechanism for the acid dehydration of cyclobutylcarbinol. Q.39 C2H5OH
PC 5
'
> (A) -
KCN
> (B) -
->(C)
->(D) + (C)
(E)
(A)
->(B)
[13]
EXERCISE-III
Q. 1 Compound (A) gives Lucas test within 5 minutes. 6g (A) when reacts with Na, 1120 mL of H2 is generated at STP. fA) having one oxygen per molecule. What is the structural formula of (A)? Compound (A) when treated with PBr3 gives (B) which when treated with benzene in presence of anhydrous A1C13 gives (C). What are (B) and (C)? An open chain compound (A) C5HgO is optically active. When (A) is hydrogenated in presence of Pd as catalyst, it absorbs two moles of F^ per mole of (A) to produce compound (B) C 5 H 12 0 which is optically inactive. However when (A) is warmed with dilute E^SC^ in presence of HgS04 it gives compound C(C5H10O2) which is still optically active. C responds to iodoform test. What are the structures of A to C? An organic compound (A) C10H12O gives red colour when treated with cerric ammonium nitrate & also decolourises Br2 in CC14 to give B (C10H12OBr2). A can show both geometrical & optical isomerism. A on treatment with L, & NaOH gives iodoform & an acid (C) after acidification. Give the structures ofA to C & also the stereoisomers ofA. A(C7H]4) decolorises Br2 in CC14 reacts with Hg(OAc)2. THF-NaBH4 to form B (resolvable compound) A C < K M n Q ^ - 3 hexanol
2.Zn/H20
Q.2
Q .3
Q. 4
l.B 2 H 6 .THF
2 H 0 1 /0H3
>
E (chiral)
YMaD
>G<
KMn0 4 /alkaline
2 m e t h y l
2.Zn/H20
Suggest short, efficient reaction sequence suitable for preparing each of the following compounds from the given starting materials and any necessary organic or inorganic reagents. CH2OCH3 from - COCH, (ii) frombromobenzene and cyclohexanol
(0
(iii)
(iv)
(v)
(vi)
Q.6
A compound (X) reacts with thionyl chloride to give a compound (Y). (Y) reacts with Mg to form a Grignard reagent, which is treated with acetone and the product is hydrolysed to give 2-methyl-2-butanol. What are structural formulae of (X) and (Y)?
fe Bansal Classes
[13]
Q. 7
The compound (D) reacts with BH3- Tetrahydrofuran and then alkaline H 2 0 2 to give chiral (E). Oxidation of (E) with KMn04 (acidified) gives a chiral carboxylic acid (F). Ozonolysis of 'D' gives after reduction with Zn the same compound (G), which is obtained by oxidation of 2-methyl-3 -pentanol with acidified KMn04. Identify (D), (E), (F) and (G). An organic compound (A) contains 60.12% Carbon, 13.13% Hydrogen and has vapour density 3 0. On oxidation it gives (B) C 3 H 6 0 which on further oxidation by NaOH +12 produces a salt of the acid (C) C2H402. When (B) is treated with hydroxyl amine, a compound of molecular formula C3H7NO (D) is formed. What are (A), (B),(C) and (D)? Compound (A) C 4 H |0 O reacts rapidly with metallic sodium, but undergos almost no reaction with Lucas reagent. When (A) is treated with hot concentrated sulphuric acid, a new compound (B) C4H8 is formed. If C4Hg is hydrated with sulphuric acid a new compound (C) C4H9OH is formed, which is almost inert to metallic sodium but reacts rapidly with Lucas reagent. What are (A), (B) and (C)?
Q. 8
Q. 9
Q. 10 A compound (X) containing C, H and 0 is unreactive towards sodium. It does not add bromine. It does also not react with Schiffs reagent. On refluxing with an excess ofHI, (X) gives only (Y). (Y) on hydrolysis gives (Z) which can be converted to (Y) by the action of P +12, Compound (Z) on oxidation gives an acid of equivalent weight 60. What are (X), (Y) and (Z)? Q. 11 A compound (A) C ; H lf) n^ yields on acetylation (B) of formula C12H1808. How many hydroxyl groups are present in compound? A l s o write structures of (A) and (B). Q. 12 An optically active alcohol (A) (C6H10G) absorbs two moles of hydrogen per mole of (A) upon catalytic hydrogenation and gives a product (B). The compound (B) is resistant to oxidation by Cr0 3 and does not show any optical activity. Deduce the structures of (A) and (B). Q.13 An unsaturated hydrocarbon (A) on hydration gave alcohol (B). Oxidation of (B) gave a ketone (C). When the hydrocarbon (A) was submitted to ozonolysis it gave formaldehyde and acetaldehyde. What one formula would you assign to A, B and C? Give the reactions involved.
Q. 14 Compound (A) reacts with sodium to liberate H2 forming a compound (B). When (A) is treated with HC1 + ZnCl2, an immediate reaction takes place liberating (C). When (A) is heated with H2S04, (D) is formed. Ozonolysis of (D) gives a three carbon ketone and another isomeric compound. What are (A), (B), (C) and (D) ? Q.15 An organic compound (A) (C4H]0O) reacts with HI giving a compound (B) (C4Hgl) which on reduction gives a normat hydrocarbon having four carbon atoms. On oxidation A gives compound (C) (C4HgO) and then an acid (D) (C4H802). Deduce th structures of, B, C and D giving reasons.
Q. 16 An organic compound (A) gives hydrogen on reacting with sodium. It also gives iodoform test and forms an aldehyde of molecular formula (B) (C2H40) on oxidation. Name the compound (A) and (B). Q.17 An organic compound (X) on analysis gives 24.24% C, 4.04%H. Further sodium extract of 1.0 g of (X) gives 2.90 g ofAgCl with acidified AgNO, solution. The compound (X) may be represented by two isomeric structures (Y) and (Z). (Y) on treatment with aqueous KOH solution gives a dihydroxy compound, while (Z) on similar treatment gives ethanal. Find out (X), (Y) and (Z).
fe Bansal Classes
[13]
Q.18 Compound (X) (C5HgO) does not react appreciably with Lucas reagent at room temperature but gives a precipitate with ammonical silver nitrate. With excess ofMeMgBr, 0.42 g of (X) gives 224 ml CH4 at STP. Treatment of (X) with H2 in presence of Pt catalyst followed by boiling with excess HI gives n-pentane. Suggest structure for (X) and write the equations involved. Q. 19 An alcohol (A) when heated with concentrated H^SC^ gives an alkene (B). When (B) is bubbled through bromine water and the product obtained is dehydrohalogenated with excess of sodamide, a new compound (C) is obtained. The compound (C) give (D) when treated with dilute H^SC^ in presence of HgS04. (D) can also be obtained either by oxidising (A) with KMn04 orfromacetic acid through its calcium salt. Identify (A), (B), (C) and (D). Q. 20 Compound (A) contains only carbon and hydrogen. It decolorizes bromine in CC14 solution and reacts slowly with concentrated HjSO^ Compound (A) reacts withHBr to form (B). (B) reacts with NaOH to form (C). (C) on oxidation gave hexanone-3. Write structures of (A), (B) and (C). Q. 21 A hydrocarbon (A) (molecular formula C5HJ0) yield 2-methylbutane on catalytic hydrogenation. (A) adds HBr in accordance with Markownikoff s rule to form a compound (B), which on reaction with silver hydroxide forms an alcohol (C) C5H120. Alcohol (C) on oxidation gives a ketone (D). Deduce (A) to (D) and give the reactions involved. Q.22 (A)
'
250C
150C
(^-Wk^A)
' (ii)H202,0H'
In the above reactions scheme (A) and (C) are isomers. (B) has a formula of C5H10. (C) Can also be obtained from the product of the reactions of CH3CH2MgBr and (CH3)2CO. Give structures of (A), (B)and(C).
fe Bansal Classes
[13]
EXERCISE-IV (A)
Q.l
l O j
+ C0 2 >
x -J*"-*
w(OJ
Q.2
<B)(OJ
(O^J
(D)glC00Ni
[JEE 1992J
The products of combustion of an aliphatic thiol (RSH) at 298 K are: (A) C02(/), H 2 0 (g) and S02(g) (B) C02(g), H 2 0 (g) and S0 2 (g) (C) CO2(l), H 2 0 (I) and S0 2 (g) (D) C02(g), H^O (I) and S02(/)
Q. 3
An organic compound C 3 H 6 0 does not give aprecipitate with 2,4-dinitrophenyl hydrazine reagent and does not react with sodium metal. It could be: [JEE 1993] (A) CH3-CH2-CHO (B) CH3-CO-CH3 (C) CH2=CH-CH2OH (D) CH2= CH-OCH3 The reaction products of C6H5OCH3 + HI A > are: [JEE 1995] (A) C6H5OH + CH3I (B) C6H5I + CH3OH (C) C6H5CH3 + HOI (D) C6H6 + CH3OI The order of reactivity of the following alcohols:
CH 3
Q .4
Q5
[JEE 1997]
CH 3
F
U)
on I
/
V 0 H
CH3
Y
an)
OH
CH 3
Ph
(IV)
OH
(II)
towards conc. HClis: (A) 1 > II > III > IV Q.6 Q.7
.Among the following compounds, the strongest acid is: (A) HC=CH (B)C6H6 (C) C2H6
Benzenediazonium cliloride on reaction with phenol in weakly basic medium gives: (A) Diphenyl ether (B) p-hydrooxyazobenzene (C) Chlorobenzene (D) Benzene Which one of the following will most readily be dehydrated in acidic condition:
Q. 8
[JEE 2000]
AA
V
OH
\
cb) A
/ V
OH
\
A X
YX
0 H
0 H
Q.9
1 -propanol & 2-propanol can be best distinguished by: (A) Oxidation with alkaline KMn04 followed by reaction with Fehling solution (B) Oxidation with acedic dichromate followed by reaction with Fehling solution (C) Oxidation by heating with copper followed by reaction with Fehling solution (D) Oxidation with concentrated H 2 S0 4followedby reaction with Fehling Classes Alcohols & Ethers
[JEE2001]
fe Bansal
[13]
Q. 10
Identify the correct order ofboiling point ofthe following compounds: CH 3 CH 2 CH 2 CH 2 OH CH 3 CH 2 CH 2 CHO CH 3 CH 2 CH 2 COOH 1 2 3 (A) 1 > 2 > 3 (B) 3 > 1 > 2 (C) 1 > 3 > 2 (D)3>2>1
O Na+(excess)
; OH(anhydrous)
[JEE 2002]
Q.ll
< O ^ O H
C2H5I
(A) < 0 } - O C 2 H 5 Q. 12
< B ) @ - I
Reaction of entainomerically pure acid with 1 chiral carbon and racemic alcohol with 1 chiral carbon [JEE 2003] gives an ester which is: (B) Optically active mixture (A) Meso (D) Enantionmerically pure (C) Racemic mixture On acid catalysed hydration, 2-phenyl propene gives: (A) 3-phenyl-2-propanol (B) 2-phenyl-1 -propanol (C) 1 -phenyl-3 -propanol (D) 2-phenyl-2-propanol Phenyl magnesium bromide reacting with t-Butyl alcohol gives CH, (A) Ph - OH (B) P h - H (C) Ph-0-C~C:H 3 CH [JEE 2004]
Q.13
Q. 14
[JEE 2005]
/CH3
( D ) PI1-C-CH3 \ CH, [JEE 2005] (D)HCl + ZnCl2
Q.15
Which is the best reagent to convert cyclohexanol into cyclohexene. (A) conc. HC1 (B)conc.HBr (C) conc. H 3 P0 4 CH3H CH 3
Q. 16
Compound (X) C H 3 0 - < ^ O y > H following products: CH3H CH3O-<O) H CH 3 -<Q>NO2(K) OHCH 3 CH 3 -N0 2 (M) H (A) K, L CH 3 OH (B) K, M (C) L only Alcohols & Ethers CH
3
CH3H O-^> OH H
CH 3 -^(O)-N02(L) CH 3
CH3H CH 3 O-
(D) M only
^Bansal
Classes
Q 17
^ ^
> Q + Phenol
[JEE 2006]
(A)j^andCH3CH2CHO
(C)fSandCH3COCH3
i 1 I
I ]
!
feBansal
Classes
(XZ ^ Q.3
Discuss why o-hydroxy benzaldehyde is a liquid at room temperature while p-hydroxy benzaldehyde is a high melting solid? [JEE 1999] White the structures of the product A&B CH - C - 0u1 8 C H n 3 ^ ^2 n 5
h
[JEE 2000]
3 > A+B . 2
O
Q.8 Cyclobutyl bromide on treatment with magnesium in dry ether forms an organometallic A. The organometallic reacts with ethanal to give an alcohol B after mild acidification. Prolonged treatment of alcohol B with an equivalent amount ofHBr gives 1 -bromo-1 -methylcyclopentane (C). Write the structures ofA, Band explain how C is obtained from B. [JEE 2001] Identify X, Y and Z in the following synthetic scheme and write their structure. Explain the formation of labelled formaldehyde (H2C*0) as one of the products when compound Z is treated with HBr and subsequently ozonolysed. Mark the C* carbon in the entire scheme. [JEE 2001] BaC*03 + H 2 S0 4 > X (gas) [C* denotes C14] CH2 - CH - Br Q.10
(ii)X,(iii)H,0+
Q. 9
^ M * /ether >y
LlAm
-* >Z
Mention two esters produced when a racemic mixture of 2-phenyl propanoic acid is treated with (+) 2-butanol. What is the stereochemical relationship between these esters? [JEE 2003]
Q. 11 An organic compound P(C5H10O) Reacts 1015 times faster then ethylene with dil.H2S04 to give two products Q and R. Both Q and R give positive iodoform test. Identify P, Q and R and also give reason for very high reactivity of P. [JEE 2004] Q. 12 (X) C5H!3N
NaNo 2 ,HCi
-N2
> (Y)
(Optically active) Find X and Y. Is Y optically active? Write the intermediate steps.
fe Bansal
Classes
[13]
ANSWER KEY
EXER Q.IQ.8 Q.15 Q.22 Q.29 Q.36 Q.43 Q.50 B C B A A B A A Q.2 A Q.9 D Q. 16 A Q.23 B Q.30 A Q.37 A Q.44 D Q3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 C c B D C B A Q.4 Q.ll Q.18 Q.25 Q.32 Q.39 Q.46 CISE-I(A) B A C A C A C Q.5 Q. 12 Q. 19 Q.26 Q.33 Q.40 Q.47 B C D B D A C Q.6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 D A C A D C C Q.7 Q.14 Q.21 Q.28 Q.35 Q.42 Q.49 D C D B D A C
EXER CISE-I Q.l Q.5 Q.9 Q.13 Q.17 Q.21 Q.25 Q.27 Q.29 Q.3 A,C,D Q.2 C Q.7 A,B Q.6 A, B,D Q.ll Q.10 A,B,D A,D Q.15 Q.14 AB,C,D A,B,C,D Q.19 Q.18 A,B A,B,C Q.23 Q.22 C,D A,C A,B Q.26 (A) P, Q, S; (B) R,S; (A) Q,R,T, (B) R, (C) S, (D) P Q.28 (A) R, S; (B) R; (C) Q; (D) P Q.30 EXER
(B) A,C A,B,C A,C A,B,C Q.4 Q.8 Q.12 Q.16 Q.20 Q.24 B A,B,C A,B,C A,C,D A A,B,C,D
CISE-II O Ii (c) Ph - C - CH 2 - CH 2 - CH
Q2
Q.5
(A)
CH3-C-O-C-C-C-C,
(B) C H r C H 2 O H ,
(C)
CH3-CH2-CH2-CH2-OH,
faBansal
Classes
[28]
Q.9
(A) =
C H
- O H
CH 2 -OH Q.10 a > b > d > c Q. 12 (a) Lucas reagent (b) Iodoform (c) PBr3 & AgN03 (d)Na Q. 13 (a) 1-hexanol reduces organ red Cr0 3 to greenCr3^ while 1-chlorohexane gives white ppt. ofAgCl on warming with ethanolicAgN03. \ (b) n-Butanol gives a positive test with Cr0 3 in acid and evolves H2 with sodium: while dry ethyl etheris negative to both tests (c) Unlike n-pentane, diethyl ether is basic and dissolves in conc. f^SC^ (C2H5)20 + H ^ Q.14 > (C2H5)2OH++ HSO" (a) Ethyl alcoholfirstreacts with sulphuric acid to form ethyl hydrogen sulphate which readily lo ses a molecule of sulphuric acid when heated with concentrated sulphuric acid at 170C to form ethylene, (b) When sodium chloride is dissolved in water it reduces the polarity ofwater the space between water molecuules are occupied by sodium and chloride ions with the result the solubilty ofthe organic compound is reduced. Q.15 CH3I, CH 3 -0-CH 3 , CH3I
Q.16 CH
3
OH
p+12
CH,I
KCN
CH
CN
reduction
CH
CH
NH
HONO
Methanol
CH3OH
KOH(aq.)
CHGCL
C1
' CH,
Q.17
(b)
(a) In order of increasing boiling points: (I) Propane < Ethanol <Pentanol-l (ii) Butane < Butyl alcohol <1,2,3-Pentanetriol (iii) Pentane < 1 -Pentanol < 1 -Hexanol The explanion is based on molecular weight and hydrogen bonding In order ofincreasing solubility in water: (i) Propane < Pentanol-1 <Ethanol (ii) Butane < butyl alcohol < 1,2,3-Pentanetriol (iii) Pentane < 1 -Hexanol < 1 -Pentanol The explanation is based on hydrogen bonding
fe Bansal Classes
[13]
Q.18 (i)
The reaction is SN2 the smaller group forms the iodide (steric effect) & stops at thefirststage in the cold. When heated, the reaction proceeds to the second stage. (ii) Et 2 0 N o reaction as there is no active H in the compound. H (iii)
W
Me, = CH,
h s
2 4-h2
pressure
> M e 3C +
Me3C H
Pressure
> Me 3 C-0-CMe 3 +
"H+ >Me3C-0-CMe33 3
n - C3H7C02H
orB2H6
> n - C4H9OH
H+
2Et
>^^CHC^OH
> (^^CHCHO
Q. 20 The +I.E. of three methyl groups on central C-atom oftert-butyl alcohol makes is partially negative with the result that it pushes the electron pair of -OH bond towards H-atom and thus H-atom is not replaced easily. CH3 CH3"^ C CH3
t ^ - 5 + 0
h
'
-6
0-- H
+8
(less partial +ve charge) (more partial +ve charge) Q.21 Oxygen atom in diethyl ether molecule has two lone pair of electrons available for co-ordination. Therefore ethers behave as Lewis base forming oxonium salts.
r
^ > 0 : + HC1
Q.22 Proof spirit is a technical term representing 57.1 % by volume ethanol-water mixture for the purpose of tax lavied on its production. The percentage represents the weakest possible percentage which allows the gun powder to catch fire. Q. 23 Sodium metal reacts with ethanol to form sodium ethoxide ion because of active H atom in ethanol. Ether do not have such active H and thus can be dried by sodium C2H5OH + Na > C2H5ONa + - H 2
1
Q.24 Due to the formation of explosive peroxide by oxidation. Q.25 Addition of methyl alcohol or naphtha or pyridine is made into ethyl alcohol to make sure that it will not be used for bevarage purposes. This process is known as denaturation of alcohol.
^Bansal Classes
[30J
C2H5OH, C 2 H 5 HS0 4 , C 2 H 5 - 0-C 2 H 5 Ethanol being very weak Lewis base and thus reacts with stronger acid HI (i) CH3CH2COOH (ii) CH3COOCH2CH2CH3 (iii) MePhS020CH2CH2CH3
-CH 2 CH 2 CH 3
O
(iv) PhCOOH + PhCOOCH2CH2CH3
(v)
(c)
(E) CH3CH(C1)CH2CH2CH0
CJ
CH?OH
Q.30
(a)[Ol
Br NFL r 2
(b)
OMe CH2Ph
(c)Ph-CH(Cl)-CH 2OH
Me' t)H OH (d) H 3 C-CH 2 -CH 2 -CH 2 -S-CH 2 -(CH 2 ) 16 -CH 3 Q.31 (A) CH 2 =CH-CH 2 -CH 2 OH Br (C) (B) Bi-CH2CH(Br)CH2CH2OH
CH 2 OH
CI| Me H
( F ) Me-CH-CH 2
Q. 3 2 (a) m-nitrophenyl acetate (better leaving group)(b) (c) sodium salt of phenol (better nucleophile) (d) (e) Phenol (more activated aromatic ring.) Q.33
p-nitrophenyl acetate (better leaving group) sodium salt ofphenol (better nucleophile)
S n 2 attack on a carbon of a benzene ring does not occur nor does the high energy C6H5+ form by an SN1 reaction. Hence A L cannot be a product even in an excess of conc. HI R (a) Ph (b) 0 <
H
Q.36
Q 37
Ph - C - CH3 Br Classes
fe Bansal
[13]
38
" ^ / v
> -
r
2
Q.39 Q.40
H
I
H O
I I!
Q.2
Q3
0 C-C-C-C-C-C
II
Q4
1!
CO
I .11
C
I
(D) CH3 - CH - CH - CH2 - CH 3 , (G) C - C - C - C - C , C - C - C - C - C OH Q.6 C2H5OH Ethyl alcohol (X) C2H5C1 Ethyl chloride (Y)
(!lBansal Classes
[32]
H Q.7 C H 3 - C H - C = CH 2 CH 3 C 2 H 5 (DJ H CH3-CH-C-COOH CH 3 C 2 HJ (F) Q.8 (CH 3 ) 2 CHOH; CH 3 COCH 3 ; CH, - CH - C = O CH 3 C 2 H 5 (G) CH 3 COOH; CH3-CH-C-CH2OH CH 3 C 2 H 5 (E)
CHGCCHG NOH
(D)
Q.10
Q.ll
Four OH groups are present in compound A. CH 2 OCOCH 3 CH 2 CH CH CH 2 OH OH OH OH (A) C2H5 H X - C - C = CH OH (A) CHOCOCH, CHOCOCH, CH 2 OCOCH 3 (B) C2H5 CH 3 CCH 2 CH 3 OH n(B) CH 3 CH CH 3 OH (B) CH 3 C CH 3 o (C)
Q. 12
Q.13
CH 3
Vc
/ (A)
\ H
fa Bansal
Classes
[36]
Q.14
CH 3 CH 2 CH 2 C(CH 3 ) 2
CI
(C)
Q.15
(A) CH 3 CH 2 CH 2 CH 2 0H (C) CH 3 CH 2 CH 2 CHO (A) CH 3 CH 2 0H (X)C 2 H 4 C1 2 CH 2 CH 2 CH 2 C = CH OH (X)Pent CH, (B)CH 3 CHO (Y)C1CH2CH2C1
Q. 16 Q. 17 Q.18
(Z)CH 3 CHC1 2
4-yn-l-ol
Q.19 Q 20
(A)
\CHOH
C H /
(B) CH 3 -CH=CH 2
+1IBR
(C) C H . C . C H
(D) CH 3 COCH 3
> CH 3 - CH 2 - CH 2 - CH - CH 2 - CH 3 Br
(A)
(B) CH 3 - CH 2 - CH 2 - CH - CH 2 - CH 3 OH (C)
Q.21
(A) CH 2 =CH-CH(CH 3 ) 2
(B) C H 3 - C H - H C ( C H 3 ) 2 Br
(C) C H 3 - C H C H ( C H 3 ) 2 OH
(D) CH 3 CO CH(CH 3 ) 2
faBansal
Classes
[36]
EXERCISE-IV (A) Q.l Q.6 Q.ll Q.16 Q.l D D D A Q.2 B Q.7 B Q. 12 B Q.3 Q.8 Q.13 D A D Q.4 Q.9 Q.14 A C B Q.5 Q.10 Q.15 C B C
EXERCISE-IV (B) n-butanol is oxidised by KMn0 4 and not t-butanol as the latter does not contain H atom attached to carbinol carbon atom. CHjCHjCHjCHjOH + KMn0 4 -> CH,CH 2 CH 2 COOOK + Mn0 2 + KOH n-Butanol CH 3 CH3-C-CH3 +KMn04 OH t-Butanol H
j
Brown
> No reaction
Me
|
H
H+
Me
H
Q.2
CH3-C C-CH3:OH Me
-> C H 3 - C C - C H 3
1 1
HIOH Me
The ether formation involves nucleophilic substitution of alkoxide ion for halide ion. R'0~+R-X R'0~+R
Slow
->R' 0
X - ^ R ' - O - R + X-
3 alkyl halide can also involve elimination ofHX to give alkene in the presence of a base. So, it is better to start with 3 alkoxide and 1 alkyl halide, i.e., equation (b)
Q.5
Q.6
Q.7
A = C H 3 - C - 0 H , B = C2H5018H
O
fa Bansal
Classes
[36]
Br
MgBr Mg MeCHO .
BrMgOCHMe H,0
HOCHMe
Br
Me
Q.8
(A) Mechanism
HOCHMe H-,0 CHMe CHMe
(B)
(C)
Me Br~
Br
2carbonium Q.9
3 carbonium RCT+RQC
X : C O , ; Y : C H , = C H - C O O H ; Z : CH, = C H C H - O H ; C H , 0 2 2
H
Ph Q.10
Ph
CH, - C - C - O - C - CH 2 CH 3 + CH 3 - C - C - O - C - CH 2 CH 3 H O CH 3 Ph O CH,
during esterification reaction only - COOH and - OH participates. There is no effect on structure of configuration of carbon adjacent of these groups. So when () acid reacts with pure (+) alcohol two esters are produced whine are diastereoisomers of each other. CH, Q.ll P: C H 3 - C H 2 - 0 - C - C H 3 Q : CH 3 CH 2 OH R: C H 3 - C - C H 3
O
when ethylene reacts with dil. H 2 S0 4 CH 3 CH 2 is produced during rate determining step, whereas P gives resonance stabilized intermediate. CH, CH3-CH2-O-C-CH3 CH, C H 3 ~ C H 2 - O = C~CH3
due to extra stability of intermediate the rate of reaction is very fast fa Bansal Classes Alcohols & Ethers [36]
| BANSALCLASSES
TARGET IIT JEE 2007
ORGANIC CHEMISTRY
xni(XYZ)
AROMATIC COMPOUNDS
CONTENTS EXERCISE-I EXERCISE - II EXRECISE-III EXRECISE-IV(A) EXRECISE-IV(B) ANSWER KEY
EXERCISE-I
Q. 1 How many n electron are there in the following species:
(A) 2 Q.2 Q. 3
(B) 4
(C) 6
(D)8 (D) 14
Number of n electrons present in naphthalene is: (A) 2 (B) 4 (C) 10 Which of the following is not the property of benzene: (A) Characteristic smell (B) Inflammable (C) Unsaturation (D) Colourless
Q. 4
Benzene undergoes substitution reaction more easily than addition because: (A) It has a cyclic structure (B) It has three double bonds (C) It has six hydrogen atoms (D) Of resonance The order ofreactivity of following compounds: (I) <) - CI I, j (II) f-CH 2 -CH 3 (III) <()-CH(CH3)2 (IV) <|>-C(CH3)3 towards electrophilic substitution will be-[where <j>=C6H5] (A) I > II > III > IV (B) IV > III > II > I (C) II > I > III > IV (D) III > II > I > IV Which one of the following is the most basic compound: (A)C6H5-NH2 (B)C6H5-NHCH3 (C) C6H5-N(CH3)2 Find odd compound out: (A) Lindane (B)Gammexane (C) 666 (D) C6H5N(C2H5)2 (D)HCB
Q.5
Q. 6 Q.7 Q. 8 Q. 9
Which of the following reagents and conditions convert benzene to chloro-benzene: (A) Cl2, sunlight, heat (B) HC1, heat (C) HC1, sunlight, heat (D) Cl2, A1C13, cold Which order is correct for the decreasing reactivity to ring monobromination ofthe following compounds: (I)C6H5CH3 (II) C6H5COOH (III)C6H6 (IV) C6H5NO2 (A) I > II > III > IV (B) I > III > II > IV (C) II > III > IV > I (D) III > I > II > IV
Q.10 Benzene on treatment with a mixture of conc. HN0 3 and conc.H2S04 at 90C gives: (A) Nitrobenzene (B) m-Dinitrobenzene (C) p-Dinitrobenzene (D) o-Dinitrobenzene Q.ll Which of the following structures correspond to the product expected, when excess of C6H6 reacts with CH2C12 in presence of anhydrous A1C13:
(B)Q-CHC
L 2
to Bansal Classes
Aromatic Compounds
Page # 2
Q. 12
For preparing monoalky! benzene, acylation process is preferred than direct alkylation because (A) In alkylation, a poisonous gas is evolved (B) In alkylation. large amount ofheat is evolved (C ) In alkylation, pollyalkylated product is formed (D) Alkylation is very costly Benzene reacts with n-propyl chloride in the presence of anhydrous A1CL to give predominantly: (A) n-Propylbenzene (B) Isopropylbenzene (C) 3-Propyl-1 -chlorobenzene (D) No reaction In the sulphonation. acetylation andformylationofbenzene the group of effective electrophiles would be: (A) SO:,CH 3 = O.HCO (C) SO v CH 3 CHO, CO + HC1 (B) SO3.CH3 - C = O-HCO (D) HS0 3 , CH 3 CO, HCO
Q.13
Q.14
(C) 5
(D)6
The number of benzene derivatives of the formula C ? H g O is: (A) 2 (B) 3 (C)4
(D)5
Q.17
Ethyl benzene + Cl7 ( m a i n ) compound is: (A) o-& p-chloroethylbenzene (B) 1 -Chloroethylbenzene (C) 2-Chloroethy 1 benzene (D) m-Chloroethylbenzene Chlorinaton oftoluene in die presence oflight and heat followed by treatment with aqueous NaOI I gives: (A) o-Cresol (B)p-Cresol (C) 2,4-Dihydroxytoluene (D) Benzyl alcohol p-Nitrotoluene on further nitration gives:
CI-I3 CH 3 CH 9 OM
Q.18
Q.l 9
( A r ) r1 ^
N
r
NO,
NO-,
NO2 "
S (C)V^
NO,
fr (D)
^
ON o
Q.20
In the reaction of p-chlorotoluene with KNH2 in liquid NH,, the major product is: (A) o-Toluidine (B)m-Toluidine (C) p-Toluidine (D) p-Chloroanilinc Maj or product of this reaction will be:
CH,
Q.21
AICI3.A
(A) o-xylene
(B) p-xylcne
(C) both
(D) m-xylene
to Bansal
Classes
Aromatic Compounds
Page # 3
Q.22
C6H5CH3 C r 0 ^ >A >B The functional group present in B and name of the reaction would be (A) -CHO, Gattermann aldehyde synthesis (B) -CHO, Etard reaction (C) -COCH3, Friedel Crafts reaction (D) -CHO, Oxo reaction Which chloroderivative of benzene among the following would undergo-hydrolysis most readily with aq.NaOH to furnish the corresponding hydroxy derivative.
Q.23
.N02
(A)02N-/oV-C1
(
(B)02N-<O)-C1
NO2 CI (D)(oyC\
(C) Me2N
Q.24 . The order of relative reactivity of the given halides towards SN2 reaction is: (A) PhCH2Cl > PhCHClCH3 > PhCCl(CH3)2 (B) PhCH2Cl < PhCHCl(CH3) < PhCCl(CH3)2 (C)PhCHCl(CH3)>PhCH2Cl>PhCCl(CH3)2 . (D) PhCHCl(CH3)>PhCCl(CH3)2 > PhCH2Cl Q.25 An aromatic compound A' C7H6C12, gives AgCl on bonding with alcoholic AgN03 solution, and yields C?H70C1 on treatment with sodium hydroxide. 'A' on oxidation gives a mono chlorobenzoic acid which affords only one mononitro derivative. The compound A is:
CH,C1
(A)^
Q.26 (A) ArN + CuBr (C) ArN +H 3 H0 2 Q.27
(B)^C1
> ArBr H2O
>ArH
CH2CI
CH 2 CI
(C)[|rC1
(B) ArNf + PhOH
(D ) A r N + I -
(D)(OlCH2CI
> Ar ^ O V
0 H
>Ari
Which of the following substituted benzene derivatives would furnish three isomers in significant amount when one more substituent is introduced:
CI Br
<A>fol
wlSC
to Bansal Classes
Aromatic Compounds
Page # 4
Q.28
Which of the following reaction does not take place? Br (A) CH3 OCH3
knh
2 >
liq.NH,
C1
(C) V ' Q.29 H1- CI + ale. KOH > (D) 1' If Jj + NaOH
300 L 2 0 am 0 t>
300C
m-Bromotoluene is prepared by: (A) Bromination oftoluene (B) Friedel Craft's reaction of bromobenzene with CH3C1 (C) Bromination of nitrobenzene and subsequent replacement of - N 0 2 group with methyl group (D) Bromination of aceto-p-toluidine followed by hydrolysis and deamination Benzyne intermediate is not observed in:
OCH 3 CI CI
+
Q.30
(B)
(O [ )
OCH,
(A) I O I
l
, elimination addition
2
(B)
j
OCH,
, elimination addition
OCH,
(C) O I
, cine substitution
(D) O
.additionelimination
Q.32
Conc.H 2 SQ 4
(B) DDT
Q.3 3 Which ofthe following group is divalent: (A) Benzoyl (B) Benzyl Q.34 C6H6 + A
a
(C)Benzal
(D)p-Tolyl
Q. 3 5 When benzene is heated with acetic anhydride in the presence of anhydrous aluminium chloride at 80C, the product formed is: (A) Benzoic acid (B) Benzophenone (C)Acetophenone (D) Ethyl phenyl ketone
to Bansal Classes
Aromatic Compounds
Page # 5
Q.36
CJL
6 6
CH C0C1
AlClj
HCl
The end product in the above sequence is: (A) Toluene Q.37 (A) N0 2 and S0 3 (B) Ethyl benzene (B) NO+ and S0 3 (C) Both the above (C) NO+ and S0 2 (D)None (D) N0 2 and S0 2 The species responsible for nitration and sulphonationby nitric acid conc. H 2 S0 4 andfirmingH 2 S0 4 are:
Q. 3 8 (A) C H the followingreactions is notH+ example of electrophilic substitution: C H - CH + HCl Which of + + N0 C 6 H 5 N0 2 + an (B) CfiH5 + CH3C1 A1C13 > 6 5 6 6 2 3
OH
(C)C6H6 + Cl2
uvlight
> C6H6C16
(D)C6H5OH + CO + HCl
> K>)
Q.39
{ ( J ) + CH2CH2CH2C1 CH,
AC3
' '
I C
~CH
(D) chlorobenzene
If the mixture of the following four aromatic compounds on oxidation by strong oxidising agent gives:
(A) Mixture of C6H5CH2OH + C6H5COOH (B) Mixture of C6H5CHO + C6H5COOH (C) Only C6H5COOH (D) None of the above Q.42 Methyl group attached to benzene can be oxidised to carboxyl group by reacting with: (A)Fe 2 0, (B)AgN0 3 (C)KMn0 4 (D) Cr0 3
CH=CH2
Q.43
(O)
>B
Q.44
Compound A and B respectively are: (A) o-Bromostyrene, benzoic acid (B) p-Bromostyrene, benzaldehyde (C)m-Bromostyrene, benzaldehyde (D) Styrene dibromide, benzoic acid Which of the following is the strongest o,p-directing group? (A) OH (B) CI (C) Br (D) C6H5
Q .45 The reaction of benzene with CO and HCl in the presence of anhydrous A1C1, gives: (A) Chlorobenzene (B) Toluene (C) Benzyl chloride (D) Benzaldehyde to Bansal Classes Aromatic Compounds Page # 6
Q.46
Q.47
The number of benzyl ic hydrogen atoms in ethylbenzene is: (A) 3 (B)5 (C)2
"X" 2 V
(D)7
iRp.n?:ofrichioride Hydrolysis ) Y X and Y respectively are: (A) Benzene, Benzaldehyde (B) Toluene, Benzaldehyde (C) Toluene, Benzoic acid (D) Benzene, Benzoic acid Q. 4 8 Product obtained when benzoyl acetic acid is heated with soda-lime is:
ci
(a)<^0^- c o c h 3
Q.49
(b)(o^C00H
(0<0>CH3
(D)
Etard reaction in the following is: (A) Oxidation of toluene to benzaldehyde by chromylchloride (B) Oxidation of toluene to benzaldehyde by alkaline KMn0 4 (C) Dry distillation of calcium benzoate (D) Reaction of benzene with Cl2 in the presence of UV light
Q. 5 0 The highest yield of m-product is possible by the electrophilic substitution of the following: (A)C6H5CH3 (B) C6H5CH2COOC2H5 (C) C6H5CH(COOC2H5)2 (D) C6H5C(COOC2H5)3
Q-51 F
OJ
+ H2
>
(A).
^ ^
( A ) Q Q. 5 2
( B ) 0
( C ) 0
Which of the following is/are produced when a mixture of benzene vapour and oxygen is passed over V 2 0 5 catalyst at 775 K? (D) Maleic anhydride (A) Oxalic acid (B)Glyoxal (C) Fumaric acid
Q. 5 3 Which of the following is the least reactive in the case of bromination: (D)Anisole (A) Phenol (B) Aniline (C) Nitrobenzene Q. 54 No. of 7t electrons in
Ois:
(B)4 (C)5 (D)6
(A) 2
(B)
(C)
and 'B' are: Cl,LiAlH4 Cl,Zn(Hg) + conc. HCl Aromatic Compounds Page # 7
O
(C) to Bansal Classes "Cl,NaBH
Q.57
In a reaction of C6H5Y, the major product (>60%) is m-isomer, so the group Y is: (A)-COOH (B)-Cl (C) -OH (D)-NH 2 Q.5 8 Which of the following will undergo sulphonation at fastest rate ? (A)
(B)
(Q
Q.59 Aniline under acidic medium, when chlorinated, produces: (A) o-chloro aniline (B)m-chloro aniline (C)p-chloro aniline (D) Mixture ofortho and para-chloro aniline Q.60 Which of the following undergoes chlorination at fastest rate? NMe, OH NH, NHCH3
(A)
(B)|
(C)
(D)
lJ
Q. 61 Which ofthe following is most reactive towards sulphonation? (A) m-Xylene (B)o-Xylene (C) Toluene Q. 62 Which of the following undergoes sulphonation at fastest rate ? (A)C6H5NO2 (B) C6H5CH2NO2 (C) C6H5CH2CH2N02 Q.63 (D)|
(D) p-Xylene
CH 2 CH 2 NME 3
(A) [| Q. 64
(B)f|^l
(C)|
(D)
When sulphonilic acid (p-H2NC6H4S03H) is treated with excess of bromine, the product is: (A) tribromo product (B) dibromo product (C) monobromo product (D)tetrebromo product Q. 6 5 Ring nitration ofdimethyl benzene results in the formation ofonly one nitro dimethyl benzene. The dimethyl benzene is:
GH 3
(A)
a s
CH, NO,
.*>(%
CH,
no
CH,
(O i
Q.66
(A)
OCH 3
(B)
OCH 3
(C)V^
OCH 3
(D) No reaction
Q.67
(A)^^-N02 CI
to Bansal Classes
(B)
NO,
(C)
-NO,
(D)
NO,
Aromatic Compounds
Page # 8
Q.68
An aromatic compound of molecular formula CgH4Br2 was nitrated when three isomers of formula C6H3Br2N02 were obtained. The original compound is: (A) o-dibromobenzene (B) m-dibromobenzene (C) p-dibromobenzene (D) None of these Which of the following carbocations is expected to be most stable?
CH,
Q. 69
CH-,
CH,
(A) |l
H'Y
(B)
H^Y
|MJ
<c)(!
(D)
Q.70
(A)
(B)(J
(C)
(D)|
(D)5
Q. 72 Which of the following species is expected to have maximum enthalpy in an electrophilic aromatic substitution reaction?
H+ E
(II)
(IV)
(V)
Q. 7 3 For the electrophilic substitution reaction involving nitration, which of the following sequence regarding the rate of reaction is true? n > l6 -6ll6> ^6U6 ^r x6
( Q
k
C6H6
<
C6T6 C,Tfi
CfiHfi =
CfiD, =
C,Tfi
(D)
C f i H f i >'
Q. 74 For the electrophilic substitution reaction involving sulphonation, which ofthe following sequence regarding the rate of reaction is true?
(A)
K
CFIHFI >
C,D, >
C,T,
(B)
C6H6
< k
C
k
< k
C
k
(D)
CfiHfi >
CfiD
<
C,Tfi
Q. 7 5 The order of relative reactivity of the given halides towards SN1 reaction is (A) benzylchloride > p-methoxybenzylchloride > p-nitrobenzylchloride (B) p-methoxybenzylchloride > benzylchloride > p-nitrobenzylchloride (C) p-methoxybenzylchloride > p-nitrobenzylchloride > benzylchloride (D) benzylchloride > p-nitrobenzylchloride > p-methoxybenzylchloride
to Bansal Classes
Aromatic Compounds
Page # 9
EXERCISE -II Q.l Which of the following will show aromatic character:
(a)
Q.2 Q,3
00
(B>
(c)
(D)
l!)
Which aromatic compound is obtained when n-octane undergoes catalytic hydroforming: (A) ethyl benzene (B)m-Xylene (C)o-Xylene (D)p-Xylene Benzoic acid may be prepared by the oxidation of:
CH 2 CH 3 CH 2 OH COCH3 OH
(A)[o]
Q.4
(B)[o]
(Ofof
< )(Oj
In which of the following reaction t-butylbenzene is formed: (A) Benzene + iso-butyl chloride, A1C13 (C) Benzene + t-butyl alcohol
NaOH H , 0 2
Bp3 HF
'
h so
i 4
Alc 3
' >
Q.5
[OJ
395QC
'
Product is:
(A)gf0H
Q.6
(B)@t0H
W.Jf
^loT 0 1
Which of the following reactions of benzene proves the presence of three carbon-carbon double bonds in it: (A) Formation of a triozonide (B) Hydrogenation of benzene to cyclohexane (C) Formation of C6H6C16 by addition of chlorine (D) Formation ofnitrobenzene on heating benzene with a mixture ofconcentrated nitric acid and sulphuric acid Electrophile NO attacks the following in which cases NO will be at metaposition:
CCI3 N02 NMe 3 Oe
Q.7
Q. 8
^(0)
iQ(o)
Benzene is a resonance hybrid mainly of two Kekule structures. Hence: (A) Half of the molecules correspond to one structure, and half of the second structure (B) At low temperatures benzene can be separated into two structures (C) Two structures make equal contribution to resonance hybrid (D) An individual benzene molecule changes back and forth between two structures
to Bansal Classes
Aromatic Compounds
Page # 10
Q. 9
The reaction of replacement of a hydrogen atom in benzene by alkyl group can be brought about with the following reagents : (A) Alkyl chloride and A1C1, (B)AlkeneandAlCl 3 (C)Alkanol and alkali (D)Alkanol and acid Which of the following is /arefittingreaction: (A) C 6 H 5 I + 2Na + ICH 3 C 6 H 5 - CH3 (B)C 6 H 5 I + 2Na + IC 6 H 5 > C6H5 - C6H5 (C) CH3I + 2Na + ICH3 > CH, - CH3 (D) C 6 H 5 CH 2 -C1 + 2Na + C1CH2C6H5 Which of the following statements is correct: (A) Bromination of toluene occurs faster than that of benzene (B) Nitration of toluene is faster than that of ethylbenzene (C) The bromonium ion is a good nucleophile (D) Effective nitrating agent is nitrate ion Electrophilic substitution in cinnamic acid will take place at: (A) Ortho-position (B) Para-position (C) Meta-position Which of the following gives Friedel Crafts reaction?
NH, NO,
Q.10
Q.ll
Q. 12
Q.13
(A)
(B)
(Q
(D)
Q.14
CI
(A) (B)CH 2 =CH-C1 (C)CH,CH 2 C1 (D)CH 2 CH-CH 2 -C1
Q.15
The good method for converting benzene into propyl benzene is: (A) C 6 H 6 + CH3CH2CH2C1 + Anhyd. A1C13 (B) C 6 H 6 + CH 3 CH 2 COCI+Anhyd. A1C13 and then treatment with Zn/Hg/HCl (C) C 6 H 6 + CH 3 CH 2 C0C1 + Anhyd. A1C13 and then treatment with H 2 Ni (D)C6H6 + Anhyd. A1C13 + cyclopropane Which of the following will undergo nitration slow than benzene?
NH, CI NHCOCH,
Q.16
(D)
Q.17
Which of the following is ortho-para directing group? (A) CF, (B) CC1, (C) -CH=CH-COOH ( D ) - N = C
Bansal
Classes
Aromatic
Compounds
Page
#11
Q.18
Which of the following statements is true? (A) Ortho-and para-directing groups increase electron density at ortho-and para-positions (B) Meta-directing groups increase electron density at meta-position (C) Meta-directing groups decrease electron density at meta-position (D) Ortho-and para-directing groups decrease electron density at meta-position
Q. 19 Which of the following statements is/are not true? (A) All ortho-para directing groups activates the ring (B) All ortho-para directing groups except halogens activate the ring (C) All meta-directing groups have rc-bond on the atom directly attached to the ring (D) All meta directing groups are deactivating. Q.20 Which ofthe following compounds can be classified as aromatic? (A) 1,2,3-Triphenylcyclopropenium cation (B) Cyclooctatetraenyl dianion (C)Azulene (D) 10-A^lene Q.21 The structure of the compound that gives a tribromo derivative on treatment with bromine water is:
CH
'
CH3
SO3H
COOH
(B)[o1
(C)(0)
OH
(D)[oTOH
Q.22 Amongst the following, the moderately activating group is (A)NHR (B)--NHC0CH 3 (C)NR2 Q.23 (A) (B) (C) (D)
(D)CH3
False statement is / are : Although benzene contains three double bonds, normally it does not undergo addition reaction. m-chlorobromobenzene is an isomer of m-bromochlorobenzene. In benzene, carbon uses all the three porbitals for hybridization. An electron donating substituted in benzene orients the incoming electrophilic group to the meta position.
Q.24 Of the species PhSH, PhSR, PhSR and Ph - S - OR the meta-substituted product is obtained from
H A
II 0
? I
(A)PhSR
(B) PhSR
(C) PhSR
y
H 0
(D) P h - S - O R
?
II o
to Bansal Classes
Aromatic Compounds
Page # 12
Q.25
(B) (C)
+ Ph,C
>?
(Q) (R)
(S)
Cumene
Q.26 Match the following: Column I (A) C 0 2 t is evolved from NaHC03 by the reaction of
Column II
O-H
CP).
OH
(B)
(Q)
NO 2 H-N-ME
(C)
(R)
(D)
(S)
N(^O^)
to Bansal Classes
Aromatic Compounds
Page # 13
Q.27
Match the following: Column I (A) Compounds which on reaction with neutral FeCl3 gives violet / Blue colour are (B) Compounds which on reaction with Na0 3 S-^Q^)N 2 C1 gives para red dye. (C)
Column II
n>\ (P)
o o 1 1 1 1 PhC^TT ^C-
(Q)
TMoTS] _
(R)
Ph-CH2-C-CH2CH3
(D)
(S)
Q.28
Match the following: Column I (A) Compounds which gives Diels Elder's reaction in greater extent withdienophile (B) Compounds which undergoes ArSN reaction are (C) Compound which has highest aromatic characters (D) Strongest Base
Column II
(P)
(Q)
o
..(S)
to Bansal
Classes
Aromatic
Compounds
Page #14
EXERCISE-III Q. 1 Write the principal organic product in each of the following reactions: CI (i) f^YN2 L j l
| CH,
+C6H5CH2SK
>A
(ii)
NO
T N02 CI NH 2
HzNNH2
triethylene GC L YO '
> B
CF,
V
(iv)
CI
(y)
r
\ CH,
/ V
OCH3
3
JLNO 2
(vi) L j i
N0 2
C I
+CH3CH2ONa >G (vii) f | T
NO2
N 0 2
+ C6H5CH2SNa
>H
Q. 2
heat
Write the most stable resonance structure for the cyclohexadienyl anion formed by reaction of methoxide ion with o-fluoronitrobenzene. Reaction of 1,2,3-tribrom-5-nitrobenzene with sodium ethoxide in ethanol gave a single product, C8H?Br2N03, in quantitative yield. Suggest a reasonable structure for this compound. Offer an explanation for the observation that 4-chloropyridine is more reaction toward nucleophiles than 3-chloropyridine. 2-Bromo-1,3 -dimethylbenzene is inert to nucleophilic aromatic substitution on treatment with sodium amide in liquid ammonia. It is recovered unchanged even after extended contact with the reagent. Suggest an explanation for this lack of reactivity. Two isomeric phenols are obtained in comparable amounts on hydrolysis of p-iodotoluene with 1 M sodium hydroxide at 300C. Suggest reasonable structures for these two products. Given the structure ofthe cycloaddition product formed when benzyne is generated in the presence of furan.
Q. 6 Q. 7
^Bansal Classes
Aromatic Compounds
Page #15
Q.8
In each ofthe following reactions, an amine or a lithium amide derivative reacts with an aryl halide. Give the structure of the expected product and specify the mechanism by which it is formed.
Br Br X tjo
Br
Q.9
1,2,3,4,5-Pentalfluoro-6-nitrobenzene reacts readily with sodium methoxide in methanol at room temperature to yield two major products, each having the molecular formula C 7 H 3 F 4 N0 3 . Suggest reasonable structures for these two compounds. Suggest a reasonable mechanism for each ofthe following reactions: C.H.Br + CHL7(COOCHXH3)Z 7 6 3 1
^
(i)ExcessNaNH 2>NH2
Q.10 (a)
a
(c) L j J CI F
(ii)H20
> CfiH5CH(COOCH2CH3)2
CH 2 CH,CH,GH 2 COCH 2 CH 3
(i)ExcessNaNH2,NH3
>
^ T r
(ii)H20
C1
" COOCH 2 CH 3
CH 3 NCH 2 CH 2 NHCH 3
NaNH2 ether
f ^ j
CH 3 ^ ^ CH 3
(d)
F x J^OCH 2 CH 2 OH T i]
F
F w
heat
>
T
F
iT
Aromatic Compounds
Page #16
EXERCISE - IV(A) Q.l Q. 2 The cWorination oftoluene in presence of ferric cUoride gives predominatly: [JEE 1986] (A) Benzyl chloride (B) m-chlorotoluene (C) Benzal chloride (D)o-andp-chlorotoluene Aiyl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl halide due to (A) The formation of less stable carbonium ion (B) Resonance stabilization (C) Longer carbon-halogen bond (D) The inductive effect [JEE 1990] The most basic compound among the following is: (A)Benzylamine (B) Aniline (C)Aeetaniline [JEE 1990] (D) p-nitro aniline
Q.3 Q.4
Chlorination of toluene in the presence of light and heat followed by treatment with aqueous NaOH gives: (A)o-cresol (B)p-cresol (C) 2,4-dihydroxytoluene (D) Benzoic acid [JEE 1990] When nitrobenzene is treated with Br2 in presence of FeBr3 the major product formed is m-bromonitrobenzene. Statements which are related obtain the m-isomer are: [JEE 1992] (A) The electron density on meta carbon is more than on ortho and para position. + (B) The intermediate carbonium ion formed after initial attack of Br attack the meta position is least destabilized. (C) Loss of aromaticity when Br+ attacks at the ortho and para positions and not at meta position (D) Easier loss of H+ to region aromaticity form the meta position thanfromortho and para position. Choose the correct statementfromthe ones given below for two aniline in:
+
Q.5
Q.6
[JEE 1993]
NH 3
NH 3
(I) (II) (A) II is not an acceptable canonical structure because carbonium ions are less stable than ammonium ions . (B) II is not an acceptable canonical structure because it is non aromatic (C) II is not an acceptable canonical structure because the nitrogen has 10 valence electrons (D) II is an acceptable canonical structure Q.7 Most stable carbonium ion is: [JEE 1995] (A)p-N02-C6H4-+CH2 (B)C6H5+CH2 (C) p - CI - C 6 H 4 - +CH2 (D)p-CH30-C6H4 -+CH2 Arrange in order of decreasing trend towards SE reactions: [JEE 1995] (I) Chlorobenzene (II) Benzene (IH) Anilinium chloride (IV) Toluene (A) II > I > III > IV (B) III > I > II > IV (C) IV > II > I > III . (D) I > II > III > IV Among the following statements on the nitration of aromatic compounds, the false one is: [JEE 1997] (A) The rate ofbenzene is almost the same as that of hexadeuterobenzene (B) The rate of nitration of toluene is greater than that of benzene. (C) The rate of nitration of benzene is greater than that of hexadeuterobenzene (D) Nitration is an electrophilic substitution reaction
Q. 8
Q.9
Q.10 Nitrobenzene can be preparedfrombenzene by using a mixture of conc. HN0 3 and conc. H 2 S0 4 . In the nitrating mixture HN0 3 acts as a: [JEE 1997] (A) Base (B)Acid . (C) Reducing agent (D) Catalyst Q.ll Benzyl chloride (C6H5CH2C1) can be preparedfromtoluene by chlorination with: (A)S02Cl2hv (B)SOCl2 (C)Cl2hv (D)NaOCl Aromatic Compounds [JEE 1998] Page # 17
to Bansal Classes
Q.12
[JEE 1998]
w
(A)
V /
0 -
w
O"
\ 5 /
O"
Q.13
A solution of (+) -2-chloro-2-phenylethane in toluene racemises slowly n the presence of small amount of SbCl5, due to the formation of: [JEE 1999] (A) Carbanion (B)Carbene (C) Free-radical (D) Carbocation Toluene, when treated with Br2/Fe,. gives p-bromotoluene as the major product, because the CH3 group: (A) is para directing (B) is meta directing [JEE 1999] (C) activates the ring by hyperconjugation (D) deactivates the ring Amongst the following the strongest base is: [JEE 2000] (A) C6H5NH2 (B) p-02NC6H4NH2 (C) m-02NC6H4NH2 (D) C6H5CH2NH2
CH,
Q.14
Q.15
Q. 16 Identify the correct order ofreactivity in electrophilic substitution reactions ofthe following compounds :
CI
(III)[r V (IV) II
NO,
C u O
[JEE 2002]
(CH3)2NH DMF
h2C/
NH,
Q.18
Br
to Bansal
Classes
Aromatic Compounds
Page #18
Q. 19 Which of the following is obtained when 4-Methylbenzenesulphonic acid is hydrolysed with excess of sodium acetate? [JEE 2005]
(A)
(C) Ctt 3
C0
^a
(B) CH
s- O
+ S0
3
COCH3 + NaOH
SO3 N a + CHjCOOH
(D) CH3
EXERCISE - IV (B)
[ O J + (CH3)2CH.CH2C1
C H C
A1C1
3 >(A)
6 5 2H5
(i) Br,,Heat,Light
(ii)NaCN
>
An organic compound (A). CgH6 on treatment with dilute sulphuric acid containing mercuric sulphate gives a compound (B), which can also be obtained from a reaction of benzene with an acid chloride in the presence of anhydrous aluminium chloride. The compound (B), when treated with iodine in aqueous KOH, yields (C) and a yellow compound (D). Identify (A), (B), (C) and (D) with justification. Show how (B) is formed from (A) ? [JEE 1994] Toluene reacts with bromine in the presence of light to give benzyl bromine while in presence of FeBr3 it gives p-bromotoluene. Give explanation for the above observations. [JEE 1996] Show the steps to carry out the following transformations: (a) Ethylbenzene > benzene j? (b) Ethylbenzene > 2-phenylpropionic acid C6H5CH2CHC1C6H5
C6H5CH - CH2
Q. 4
Q.5
[JEE 1998]
Q.6
Q.7
alcoholicKOH.heat
(A)
(A) + (B)
[JEE 1998]
[JEE 1998]
Q. 8
Normally, benzene gives electrophilic substitution reaction rather than thus electrophilic addition reaction although it has double bonds. [JEE 2000]
Q.9 , How would you synthesis 4 methoxyphenol from bromobenzene in NOT more than five steps? State clearly the reagents used in each step and show the structures of the intermediate compounds in your synthetic scheme. [JEE 2001] Q.10Carry out following conversions in 3 or less steps.
COOH COOH
f o l
>
f o l
[JEE 2003]
to Bansal Classes
Aromatic Compounds
Page # 19
Q.ll
A compound C9H702C1 exists in keto form A and enolic form B. Enolic form B predominates at equilibrium. On oxidation with KMn0 4 1 gives m-chlorobenzoic acid gives structures ofA and B. [JEE 2003] Q. 12 7-bromo-l, 3,5-cycloheptatriene is ionic compound, whereas 5-bromo-l,3-cyclopentadiene can't ionise [JEE 2004] even n the presence ofAg, Explain why? Q.13 Give reasons: H,C
(i)|j T \
[JEE 2005]
-Br c2HsOH(ag.)
ch
>
(a)
: I I j
acidic solution
3 (ii) B r - { j K _ _
CH,
C2HsOH(aq.) ) neutral
(b)
(i)02N^S^
CH,
(ii) H3C
NaOH(aq.)
p is not liberated
CH2N02 N
(C) (i)
.0
Conc.HNO
Conc"H 2 S O 4
-O /^/
N 0
r
^
NO2
f Brown fumes and^) . NaBr + MnQ 1 _ A C on,HNo 3 ) C ( i n t e r m e d i a t e ) Q- 14 [^pungentsmell J B *" Find A, B, C and D. Also write equationsAto B and Ato C.
ffi
Aromatic Compounds
Page #20
ANSWER EXERCISE
KEY -1
Q.l Q.8 Q.15 Q.22 Q.29 Q.36 Q.43 Q.50 Q.57 Q.64 Q.71
C D B B D B D D A A B
Q.2 Q.9 Q.16 Q.23 Q.30 Q.37 Q.44 Q.51 Q.58 Q.65 Q.72
C B D A B B A A B C A
Q.3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 Q.52 Q.59 Q.66 Q.73
C B B A A C D D B B C
Q.4 Q.ll Q.18 Q.25 Q.32 Q.39 Q.46 Q.53 Q.60 Q.67 Q.74
D D D A B D C C D B A
II
Q.5 Q.12 Q.19 Q.26 Q.3 3 Q.40 Q.47 Q.54 Q.61 Q.6 8 Q.75
A C A B C B C D A B B
Q.6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 Q.55 Q.62 Q.69
D B B C B C A B D B
D B D A C C A D A D
EXERCISE-
A,B,D Q.2 A,C Q.3 A,B Q.6 A,B,C Q.7 A,B,D Q.ll Q.10 B A Q.14 C,D Q.15 C Q.18 A. Q.19 B,C,D Q.22 B Q.23 (A) Q, (B) P, (C) R, S, (D) R (A) P,Q,R,S, (B) Q, (C) P,Q,R,S, (D) p
EXERCISE-III
A,B Q.4 A,B,C,D Q.8 C A,B,C A,B Q.12 A,B B,D Q.16 C Q.20 A,B,C A,B,C B,C,D Q.24 C,D Q.26 (A) Q, (B) P,R,S, (C) R,S, (D) P,Q,R,S Q.28 (A) R, (B) S, R, (C) P, (D) S
C6H5CH?S
Q.l
(i)
NO, (ii)
H,NNH
CI (iii)
0,N
Br
NO 2 OCH 2 CH 3 .NO 2
(V)
(vi)
CH,SCH, NO,
(viii)
N'
OCH3
Br
OCH 2 CH 3 J \ .Br
NO,
Nitrogen bears a portion of the negative charge in the anionic intermediate formed in the nucleophilic addition step in 4-chloropyridine, but not in 3-chloropyridine. Y 1 1 ci 1 1 is more stable and formed faster than Aromatic Compounds Page #21
Q.5
A benzene intermediate is impossible because neither on the carbons ortho to the intended leaving group bears a proton. 3 -Methylphenol and 4-methylphenol (m-cresol and p-cresol). EXERCISE - IV(A) Q.4 D Q.5 Q.ll A,C Q.12 Q.18 D Q.19 EXERCISE - IV (B) C(CH3)3 Q.7 I no
Q.6
D C D
B C C
A A B
A,B C C
Q.6 Q.13
C D
Q.7 Q.14
D A,C
Q.l
Q-2
f O
" O M (B)(0)
o^ COOK
2-phenylpropane niitrile
COCH,
(C)(0)
+
In presence of FeBr3, Br 2 produces Br (an electrophile) which attacks the benzene ring at o-,p-position to give p-bromotoluene. In presence of light, side chain is attacked to produce benzyl bromide . (a) H-,0 (i) C 6 H 5 C H ( O H ) C = C H C 6 H 5 C H - C = C H OHJ C 6 H 5 CH=CHCHO =^C6H5CH=C=CH OH -H-,0 C 6 H 5 CH=C=CH
CFIH,
fO]
COOH
Sodalime
> [O fo]
CN CHCH3
CHOCH hv
CHXCH
KN C
-^[o
COOH CHCH3
C 6 H 5 CH 2 CH 2 CHC1C 6 H 5 CH=CH,
K0H (ALC) A
> C 6 H 5 CH= CHC 6 H 5 (Cis and trans forms) C=CNa CH,I C=C-CH,
Q.7
[ O
Br-,
,CHBrCH2Br ->fO
NaNH2 3 eq.
[ Q
Aromatic
Compounds
Page
#22
Q.8
Benzene has resonance stabilization due to delocalisationofTc-electrons. Also during electrophilic addition reactions, it loses its aromaticity. In electrophilic substitution reaction aromaticity is retained. Br
ONa
NaOH AhighPr essure
OMe
conc.H 0 SO
OMe
NaOH
Q.9
[O
SO.H OMe
H,0
OMe
ONa
Alternative rout
Br
conc.H-SO,,
OH Br Br Br OMe
Na0H
->IQ
SO.H
N0 aH
JO
ONa
Me2S04
i O ]
^ ^
A high Pressure
)[o
H,cr
OMe
ONa
OMe
OH COOH
conc.H 1 SO / 1
COOH
HBF./KHE,
COOH
Q.10
(O) 0
SO.H OH C=CH-CHO
* o
C-CH 2 -CHO
Q.ll
^ (A) . . ( B ) . Keto Enol Enol form is more stable due to extended conjugation O n (A) KMnO
C-OH
CI
Q.12
On ionization 7-bromo-1,3,4-cycloheptatriene gives tropolium ion which is aromatic with 671 electrons.
Br
()
+ Br
5-bromo-1,3-cyclopentadiene can't ionise as it will in that case give highly unstable antiaromatic cation with 4 71 electrons.
Br
-X-
Br
Aromatic
Compounds
Page #23
CH3 Q.13 (a) (i) H5C6 - C - OC2H5 + HBr(acid); (ii) no reaction due to partial double bond character
CH
I-
(b) (i)
CH3 (c) (i) due to presence of lone pair of nitrogen atom NO group is electron denating and ortho, para directing (ii) N0 2 group is electron withdrawing and meta directing (d) Due to reduction of central ring, three four membered antiaromatic rings become stable while on recuction of terminal ring only one antiaromatic ring can be stabilized.
CH 3
t^J
NO,
to Bansal Classes
Aromatic Compounds
Page # 24
I BANSALCLASSES
^
ORGANIC CHEMISTRY
XII (ALL)
CARBONYL COMPOUND
CONTENTS EXERCISE 1(A) EXERCISE 1(B) EXERCISE II EXER CI SE III EXERCISE IV (A) EXER CISEIV (B) ANSWER KEY
EXERC1SE-UA) Q. 1 Gem dihalide on hydrolysis gives: (A) Vic did (C) Carbonyl compound In the given reaction: OH (B) Gem diol (D) Carboxylic acid
Q.2
CH3-CHC-CH3 CH3
OH
(a) + (b)
(a) and (b) respectively be: (A) CH3CHO and CH3CHO (C) CH3COCH3 and CH3COCH3 Q.3
Acetophenone can be obtained by the distillation of: (A) (C6H5COO)2Ca (B) (CH3COO)2Ca (C) (C6H5COO)2Ca and (CH3COO)2Ca (D) (C6H5COO)2Ca and (HCOO)2Ca Arrange these compounds in decreasing order of reactivity for the nucleophilic addition reaction: (I) Acid chloride (II) Aldehyde (III) Ketone (IV) Ester Select the correct answer from the codes given below: (A) I > II > III > IV (B) IV > III > II > I (C)III>II>I>IV (D) I > IV > II > III Acetalorketalis: (A) Vic dialkoxy compound (C) a-alkoxy alcohol In the given reaction (B ) a, o-dialkoxy compound (D) Gem dialkoxy compound
Q. 4
Q.5
Q.6
O
CHd3 -CH 2? -C-CH 2 COOC 7 H s 2 W >(A)
(i)LiA1H
(ii)H20/H
4 )
o
[X] will be: (A) HCHO CH 2 -OH <C4H,-OH+ OH (D)HCN CH 2 -OH (B)IH H
fa Bansal Classes
Carbonyl Compound
[21]
Q.7
II O
NH2OH/H
[X]
[X] will be: (A) Only syn oxime (C) mixture of syn and anti oxime Q.8 Schiffs base is prepared from: (A) Carbonyl compound and primary amine (C) Carbonyl compound and tertiary amine
(B) Only anti oxime (D) secondary amide (B) Carbonyl compound and secondary amine (D) All of these
Q.9
Schiffs reagent is used for the differentiation between: (A) HCHO and CH3CHO (B) CH3COCH3 and CH3CHO
O II
(D) HCHO and C6H5CHO Q.10 In the reaction sequence, [X] is ketone:
o II
O
(A)[ 1 (B)[
O
|
0
(C)^ Y 3 (D)" 3 '
Q.ll
Which one of the following compounds will give dimethyl glyoxal with Se02: (A) Acetone (B) Acetophenone (C) Ethyl methyl ketone (D) Propanaldehyde
O
( ^ J C H 3 -J5a-> [X] [X] will be:
9
ft
" U
Q.13 Consider the given reaction:
O
C H
3
O
3 c
- C - C H
c o o o h
> C H
- C -
O -
C H
The above reaction is known as : (A) Baeyer-villiger oxidation (C) Periodate oxidation fa Bansal Classes
Q.14 Q.15
(C) N a / H g / H ^
Arrange acidity of given four compounds in decreasing order: (I) CH3 - C - CH2 - C - CH3 (II) CH3 - C - CH3 (III) CH=CH (IV) CH,-CHO
Select correct answer from the codes given below: Codes: (A) I > IV> III > II (B) I > IV >11 >111 (C) III > I > IV > II Q.16 In the given reaction OH
x
+Y -
NaOH
5C
CH3 (X) and (Y) will respectively be: (A) CH 3 -CH 2 -CHO and CH 3 -CH 2 -CHO (B) CH3-CHO and CH 3 -CH 2 -CHO CH3 (C) CH3-CHO and CH r CHO Q.17 Number of products in the given reaction: C6HsCHO + CH3-CHO (B) Three
OH
(D) CH3-CHO and CH3 - C - CHO CH, > Product (C)Two (D)Four
r + w
" w
OH
5h/a
> [X]
O
OH
OH
O i ( D ) ( ^
(A)f Q.19
(B)[
i (c)[
Product ofPerkin reaction is: (A) a, P-unsaturated aldehyde (C) P-Aryl-a, {3-unsaturated acid
(!Bansal
Classes
Carbonyl Compound
ISJ
Q 20
[X] will be: (A) C 6 H 5 -CH =CH-COOH (C) C 6 H 5 -CH=C-COOH (B) N O 2 - < o ) - C H = C H - C O O H (D) N 0 2 - { o ) - CH = C - G O O H c6H5 *no2 Q.21 In the given reaction OH QHXHO + X
6 5
> C 6 H 5 - CH - CH 2 - COOC 2 H 5
(ii)HOH/NH4Ci
6 5 2 2 5
[X] will be: (A) CH 3 -COOC 2 H 5 (C) BrXH 2 -COOC 2 H 5 Q.22 The given reaction
Cannizzaro reaction is example of: (A) Redox reaction (B) Disproportionation (C) Both (A) and (B) CH 2 OH
Q. 24
Acetaldehyde can be converted into HO CH 2 - C - CH 2 OH by which reagent? CH 2 OH (A) KOH (C) excess of HCHO and KOH (B) KOH followed by LAH (D) KCN followed by SBH
Q.25
Metaformaldehyde is: (A) Dimmer of HCHO (B) Trimer of formaldehyde (C) Tetramer of formaldehyde (D) Polymer in which number of HCHO unit is more than 100
(!Bansal Classes
Carbonyl
Compound
ISJ
Q.26
[X] will be: (A) Methyl oxide (C) 1,3, 5-Trimethylbenzene Q.27
Which will give silver mirror test with Tollens reagent: (A)C6H5CHO (B)CH 3 -CHO (C) HCOOH
Q.28
Which one of the combinations will give propanaldehyde on dry distillation? (A) (C6H5COO)2Ca and (HCOO)2Ca (B) (CH3COO)2Ca and (CH3CH2-COO)2Ca (C) (CH3-CH2-COO)2Ca and (HCOO)2Ca (D) (CH3COO)2Ca and (CH3COO)2Ca Grignard reagents do not give carbonyl compounds with: (A) C0 2 (B) RCOC1 (C) RC-N In the reaction sequence: Cyclohexane (Z) will be: (A)Hexanal The given reaction
OH Aluminium tertiary butoxide j) Acetone ^ __hv/ci2
Q.29
(D)RCOOR
Q.30
> (X)
aio.KOH/A
>(Y)
(B) 2-Hexanone
O
(C) 3-Hexanone
Q.31
is knows as: (A) Kolbe reaction Q. 3 2 In the given reaction: (B) Tischenko reaction (C) MPV reaction (D) Oppeneur oxidation
C BH 3 O
t
ii)H202/0H
(!Bansal
Classes
Carbonyl Compound
ISJ
Q.3 3 Cyanohydrin of which compound on hydrolysis will give lactic acid? (A)C6H5CHO (B)HCHO (C) CH3CHO Q.34 In the reaction sequence: CH.OH-CHOH-CH^OH KHS(
(D) CH3-CH2-CHO
V A > ( X ) _JC2H5O)3M
A
)(Y)
(Y) will be: (A) CH2=CH-CHO (B) CH2=CH-CH20H (C) Mixture of CH2=CH-COOH and CH2=CH-CH2OH (D) CH2 = CH - C - O - CH2 - C H = CH2 Q.35 Acetaldehyde cannot give: (A) Iodoform test (B) Lucas test
O I I
Q.36 The reaction in which NaCN/C2H5OH/HOH is used is: (A) Perkin reaction (B) Benzoin condensation (C) Reimer-Tieman reaction (D) Rosenmunds reduction Q.37 Compound (A) an aldol TT^TI
3
CHUrl
O LU H
(B) an acetal
(C)aketal
(D)ahemiacetal
Question No. 38 to 40 (3 questions) An alkene (A) C16H16 on ozonolysis gives only product (B) C8H8C. (B) also can be obtained by hydrolysis of the product obtained by reaction between cyano benzene and CH3MgBr. (A) can show geometrical isomerism and it can decolourise Br2 water. (B) on treatment with Se02 produces (C). Q.38 Which is not correct about (A)? (A) Ais optically inactive (B) On catalytic hydrogenation 'trans' form ofAproduces racemic mixture (C) A can be prepared by Witting reaction on acetophenone with Ph3P = C(CH3)Ph. (D) On treatment with per acid followed by hydrolysis 'trans' form ofAproduces racemic mixture Q.39 Which is not correct about B? (A) It gives iodoform test (B) On treatment with LiAlH4, H p it produces a compound which also responds to iodoform test. (C) It gives Tollen's test (D) On treatment with NH^NH^ EtO" at high temperature it produces ethyl benzene Q.40 Which is not correct about C? (A) On treatment with NaBH4 it will produce a diol. (B) On treatment with OH (conc.) followed by acidification it produces an optically active acid. (C) It gives Tollen's test (D) It can take part in aldol condensation
fa Bansal Classes
Carbonyl Compound
[21]
Q. 41 Questions given below consist oftwo statements each printed as Assertion (A) and Reason (R); while answering these questions you are required to choose any one of the following four responses: (A) if both (A) and (R) are true and (R) is the correct explanation of (A) (B) if both (A) and (R) are true but (R) is not correct explanation of (A) (C) if (A) is true but (R) is false (D) if (A) is false and (R) is true Assertion: Benzaldehyde with HCN gives two isomeric compounds Reason:
C02H
Both nitrile and isonitrile compounds are possible when HCN reacts with carbonyl group.
C02H OH HO OH OH OH HOOH OH CO?H CO 2 H HOOH OH OH OH
Q. 42 When D-glucose is treated with Br, water then the product is:
OH HO OH OH
(A)
(B)
(Q
(D)
OH OH OH
OH
Q.43 A is:
OH
[(CH^CQ] 3 A1
(A)
(B)
(Q
(D)
CH=CH-CHO
LlA1H4
p r o d u c t is
fa Bansal Classes
Carbonyl Compound
[21]
Question No. 45 to 49 (5 questions) Compound 'C fCF, - C - C ( C H 3 ) 3 1 was prepared in a three step sequence from ethyl trifluoroacetate.
The first step in a sequence involved treating ethyl trifluoroacetate with NH 3 to give a compound A. A on treatment with reagent 'X' (alongwith gentle heating) produces a compound B (which on hydrolysis can produce an acid). B on treatment with an orango metallic, 'Y', followed by hyydrolysis produces C. Based on above passing attempt the following questions: Q.45 Structutre o f ' A would be
(A)
J! c
^OCH2CH?
Ic I
(C) C F ^ ^ O C H . C H ,
NH,
Q 46
Structure of B would be
O
(A) CF, - C - N H 2 Q.47 'X' should be (A) B a 0 2 (B) CF 3 -C=N (C) C F 3 - C H 2 - C N (D) C F 3 - C H 2 - N H 2
(B)H202
(C)P4O10
(D)N20
Q. 48
O
(A) CF3 - C - O - C(CH 3 ) 3 (C) CF3 - C - OH
0
(B) ( C H 3 ) 3 C - C - OCF 3 (D) (CH 3 ) 3 C-OH
O rSH -SH
Q.49 C
CF3
RaneyNi
E : 'E' is
CF3
\ /
/
C
\ /
(A)
(CH 3 ) 3 C
\
OH H
(B)
(CH3)3C
/ X
S
CF 3
\ /
c
(C)
(CH3)3C
\
H
(D)CF3-C-S-C(CH3)3
<!%Bansal Classes
Carbonyl Compound
[9]
faiBansal Classes
Carbonyl Compound
[10]
(A) C H 3 - C - C H 3 o II (C) Ph - C - CH 3
Q.2
C H - C2H5 CH,
- i
i ) 0
>
(B) CH 3 -CH=CH 2
CO/H2/CO2(CO)S__>
(II)H,0
- C = C H - M ^
NaOH,H202
(D)
CH3-C.CH
Q. 3
Which one of the following alcohols can be oxidised by K 2 Cr0 4 ? (A) Ethanol (B) Tert butyl alcohol (C) Isopropyl alcohol
(D)Allyl alcohol
Q.4
Two isomeric ketones, 3 -pentanone and 2-pentanone can be distinguished by: (A) I , / N a O H (B)NaS0 3 H (C) NaCN / HCl (D) 2,4-DNP Consider the structure of given alcohol: OH C g H 5 - C - CH3 C2H5 This alcohol can be prepared from: (A) C 6 H 5 - C - CH 3 and C 2 H 5 MgBr (C) C 6 H 5 O II C- C 2 H 5 andCH 3 MgBr 1 1 (B) CH 3 - CH 2 - C - CH, and C 6 H 5 MgBr O II (D) C 6 H 5 - C - C l and C 2 H 5 MgCl
Q. 5
Q6
Stability ofhvdrates of carbonyl compounds depends on: (A) Steric hindrance (B) Presence of - I group on gemdiol carbon (C) Intramolecular hydrogen bonding (D) angle strain in carbonyl compound
(!Bansal
Classes
Q.7
II o
NH2OH/Ha > pq
[Y]
O II
(B) C H 3 - C - N H - C 6 H 5
O II
0
(C) C6H5 - CH2 - C - NH2 Q.8 Fehling solution gives red precipitate with: (A) Aromatic aldehyde (C) Ketones (D) C6H5CH2CN
Q.9
Silver mirror test with Tollens reagent is given by: (A) C6H5CHO (B) Ph-NH-OH (C) C6H5 - CH2 - C - CH2OH (D) CH3CO
0
Q.10 Which one ofthe following compounds will not give aldol: (A)Acetaldehyde (B) Formaldehyde (C) Pivaldehyde (D) Crotonaldehyde Q. 11 Knoevengcl reaction is catalysed by : (A)NaOH (B)NH3 (C)EtOk (D) Pyridine (D) Dimerization
Q. 12 Cross Cannizzaro reaction is an example of: (A) Redox reaction (B) Disproportionation (C) Isomerization
Q. 13 Which one of the following reagent(s) is/are used for the conversion ofketone into hydrocarbons? (A)LAH (B)N2H4/H202 (C) Mg Hg F^O (D) NaHgHCl Q. 14 Schiffs reagent gives pink colour with: (A)Acetaldehyde (B) Formic acid (C) Acetic acid (D) Methyl acetate
Q. 15 Which ofthe following compound will give positive Tollens test (A)CH3CHO (C) CH3CH2CH2CH2CH --OCH 3 OCH OH (B)Ql0I1
OCH3
^OCH,
fa Bansal Classes
Carbonyl Compound
[21]
(A)
(C) 0 < Q.17
ci & CH3CHO
C H 3
& HCHO
CH3CHO
O II
(A) Ph - C - Ph
0 II
(B) HO - (CH 2 ) 3 - C - CH 3 (D) HO - CH 2 - ( C H 2 ) 4 - C - CH 3
O II
O II
O
(A) CH^ = CH - C - H V 1 z
II (i)NaCN U) (ii)H 2 0
>
(B) CH, = C H - C - H Z
H 2 O/H
(C)|> o o (D) I
Q. 19
+ CH2(COOMe)2 o '
CH CH CN
>
U-CH-CN
Base
6 r
Which of the following can be used for protection of carbonyl group (A) CH 2 -OH-CH 2 OH / H (B) C H 2 - 0 H - C H 2 - C H 2 OH / H (C) HS-(CH 2 ) 3 -SH (D) C H 2 0 H - C H 2 - C H 0 Mixture of Ph-CHO & HCHO is treated with NaOH then Cannizzaro reaction involves: (A) Oxidation ofHCHO (B) Reduction ofHCHO (C) Oxidation of Ph-CHO (D) Reduction of Ph-CHO Acetone give addition elimination reaction with (A) Hydrotyl amine (B) Sodiumbisulphite (C) Hydrogen sulphide (D) Ylide
Q.20
Q.21
faBansal Classes
Carbonyl Compound
[13]
Q. 22 Which of the following will be soluble in sodium bicarbonate solution? OH COQH OH SOjH
() a
Q. 23
m O
() c u
c) d
Asparmate, an artificial sweetener is a peptide and has the following structure. Which ofthe following is correct about the molecule?
h 2 N^ ^ ^ N N H
7A
CH,
(A) It has four functional groups (B) It has three functional groups (C) on hydrolysis it produces only one amino acid (D) on hydrolysis it produces a mixture of amino acids Q. 24 Match List-I with List-II and select the correct answer using the codes given below the lists. List-I (Compound) List-II (Used as) (A) (B) 1,4 addition Tautomerism (P) (Q) O II P h - C H 2 - C - C H = CH2 PCC O (C) (D) Allylic bromination Preparation of Ketonefrom2 alcohol (R) (S) NBS
Q. 25 Match list-1 with list-11 and select the correct answer using the codes give below the lists: List-I List-II (A) (B) (C) (D) CH 2 CH-CHO KaB 4
"
>
(!Bansal Classes
Carbonyl Compound
ISJ
Q. 26
Match list-I with list-II and select the correct answer using the codes give below the lists: List-I List-II (A) C 6 H 5 CHO + HCHO (B) C 6 H 5 -H+CH 3 COCI (C) C 6 H 6 +CO+HCI
OH
0H
ANHY ALC 3
ANHY ZNC 2
Cu.,CL
'
> C 6 H5 -CHQ 5
OH
(O)
' -
)[qJ"CH0
(!Bansal Classes
Carbonyl
Compound
ISJ
Q. 3 (b) Equilibrium constants for the dissociation (Kdiss) of cyanohydrins according to the equation OH RCR' CN Aldehyde Hydrogen or ketone cyanide have been measured for a number of cyanohydrins. Which cyanohydrin in each of the following pairs has the greater dissociation constant ? OH Cyanohydrin
I I
Kdiss
RCR' + HCN
I I
OH
(i) (ii)
or
(CH3)2CCN
H CfiH<CCN 6 5 ? <
CH, Some Grignard reagents react with ethyl orthoformate, followed by acidic hydrolysis, to give aldehydes. Propose mechanisms for the two steps in this synthesis. O-CH 2 CH 3 H-C-0-CH2CH3 +R-Mg-X O-CH 2 CH 3 ethyl orthoformate O-CH 2 CH 3 >R-C-0-CH2CH3 H acetal aldehyde H3O+ >
PV 0
Q. 4
J}
Q. 5
Suggest a resonable mechanism for each of the following reactions: (CH3)3Cx/Ox .C CH,
Cr
NaQCH3
CH3OH
|| (CH3)3CCCH2OCH3
(88%)
Q. 6 (a)
O
CH3-C-CH3+HO-CH2-CH2-NH2 .CH 2 - CH 2 - CH 7 -NII 2
w
"2M >
Q o
o
"
C - CH3 - COCb/NeOH/HDH
)
(C)
\ /
(ii) H
fa Bansal Classes
Carbonyl Compound
[21]
Q.7
A synthesis that begins with 3,3-dimethyl-2-butanone gives the epoxide shown. Suggest reagents appropriate for each step in the synthesis. 0 O
54%
OH >(CH3)3CCHCH2Br
68%
(CH3)3CCCH3)3CCCH2Br
>(CH3)3 CC>"cH2 H
Q. 8
Show how you would accomplish the following syntheses efficiently and in good yield. You may use any necessary reagents. O (a)\ ^ CHO O CH2OH CHCH2CH3 0
(b)
CHO
CHO
CHO
CHO
(,!
Q. 9 O
r - r r r
c r f - + c r i ?
0
(76%)
(B)
>
(G)
H2O/H+/A
>
(D)
> ( A )
> ( c )
>
(D) Q. 12 Give the structure of the substance for each of the following reaction: O
y O
(a) (X) NaOH/A
>
11
c-
CH 3
(b)
(Y)
NaOH/A
>
\\
CH
(!Bansal Classes
Carbonyl Compound
ISJ
(C)
(Z)
o Q.13 Each of the following reactions has been reported in the chemical literature. Write the structure of the product (s) formed in each case.
(a)
(b)
CI
Q.14
IdentifyAtoE: CH^x/^O
LSH H 2 /Pt
<fy
Conc, H 2 S 0 4 / A * 0 )
TR)
H2Q
>
(C)
NH3/A
)(
T>)
(i)BH3/THF (ii) H 2 0 / H
(p )
Q. 16 CI
I ^ S l ^ J
W
_ D M S O ^
( A )
.(B)
C (ii)HOH
(C)
BA0
'",,A
' ( D ) ^ F ^ ( E )
K O H / A
Q.17
(a) (B)
Syntheses of each of the following compounds have been reported in the chemical literature. Using the indicated starting material and any necessary organic or inorganic reagents, describe short sequence of reactions that would be appropriate for each transformation. 1,1,5-Trimethylcyclononane from 5,5-dimethylcyclononanone / A J FROM C 6 H 5 C
H X
u
(!Bansal Classes
Carbonyl Compound ISJ
EXERCISE-III Q. 1 Compound (A) C9H, 0O is inert to Br2 / CC14 and on vigrous oxidation with hot alkaline KMn04 yields benzoic acid. (A) gives red precipitate with 2,4 DNP / HC1 / A. (a) Write all possible structures of [A] and (b) How can these isomers be distinguished by chemical tests? Compound (A) C8HgO is water insoluble and gives yellow precipitate with I2/NaOH. It reacts with NH^OH in the presence of NH4C1 /NH4OH to give two geometrical isomers (B) and (C) having MF CgHgON. These two compounds do not undergo dehydration. What will be structures of (A), (B) and (C) ? A dithiane synthesis can convert an aldehyde to a ketone. The aldehyde isfirstconverted to its dithiane derivative, which is deprotonated and alkylated. A mercuric chloride - assisted hydrolysis gives the ketone. Show how this techinque might be used to convert benzaldehyde to benzyl phenyl ketone Wolff-Kishner reduction (hydrazine, KOH, ethylene glycol, 130C) of the compound shown gave compound A. Treatment of compound A with m-chloroperoxybenzoic acid gave compound B, which on reduction with lithium aluminium hydride gave compound C. Oxidation of compound C with chromic acid gave compound D (C9HI40). Identify compounds A through Din this sequence.
Q.2
Q. 3
Q.4
COQ. 5 Reaction ofbenzaldehyde with 1,2-octanediol in benzene containing a small amount of p-toulenesulfonic acid yields almost equal quantities of two products in a combined yield of 94%. Both products have the molecular formula CI5H22U, Suggest reasonable structure for these products. The sex attractant of the female winter moth has been identified as the tetraene CH3(CH2)8CH=CHCH2CH=CHCH2CH=CHCH-CH2. Devise a synthesis of this material from 3,6-hexadecadien-l-ol and allyl alcohol. Hydrolysis of a compound A in dilute aqueous hydrochloric acid gave (along with methonal) a compound B, mp 164-165C. Compound B had the molecular formula C )6 H I6 0 4 . Whatistheresonable structure for compound B? /^-CHCH(0CH3)2 OH
Compound A
Q.6
Q. 7
Q. 8
When HO-CHJ-CHJ-CHJ-CHJ-CHO this compound is dissolved in water it exist in the equilibrium ofisomeric forms. Both forms are ring-chain isomers. Write the structure ofisomeric cyclic form and give mechanism for the formation of cyclic form. When (I) is treated with CH3OH in dry HC1 a newproduct (iii) is obtained. Give structure of this compound. Compound (A) C5Hg, decolourises bromine water and on reduction with H2/Pt gives compound (B) having MF C5H!2. A gives compound (C) with I V Lindlars catalyst and compound (D) with Na/NH3 (/). Compound (C) and (D) are isomers having MF C5HK). (A) on hydration gives two isomeric compounds (E) and (F) having MF C5H10O. (E) gives yellow precipitate with 12 / NaOH but (F) does not. What will be the structures of (A) to (F) ?
Q. 9
Q. 10 An organic compound (A) contains 40% carbon and 6.7% hydrogen. Its vapour density is 15. On reacting with a concentrated solution of potassium hydroxide, it gives two compounds (B) and (C). When (B) is oxidised, original compound (A) is obtained. When (C) is treated with concentrated HC1, it gives a compound (D) which reduces Fehling and ammonical AgN0 3 solution and also gives effervescences with sodium bicarbonate solution. Write structures of (A), (B), (C) and (D) and explain reaction.
tBansal
Clt
Carbonyl Compound
EXERCISE-IV (A) Q. 1 The formation of cyanohydrin from a ketone is an example of: (A) Electrophilic addition (B) Nucleophilic addition (C) Nucleophilic substitution (D) Electrophilic substitution [IIT1990]
Q.2
The enolicformof acetone contains: [IIT 1990] (A) 9 sigma bonds, 1 pi bond and 2 lone pairs (B) 8 sigma bonds, 2 pi bonds and 2 lone pairs (C) 10 sigma bonds, 1 pi bond and 1 lone pair (D) 9 sigma bonds, 2 pi bonds and 1 lone pair m-chlorobenzaldehyde on reaction with conc. KOH at room temperature gives: (A) Potassium m-chlorobenzoate and m-hydroxybenzaldehyde (B) m-hydroxybenzaldehyde and m-chlorobenzyl alcohol (C) m-chlorobenzyl and m-hydroxybenzyl alcohol (D) Potassium m-chlorobenzoate and m-chlorobenzyl alcohol Hydrogenation ofbenzoyi chloride in the presence ofPd and BaS0 4 gives: (A) Benzyl alcohol (B) Benzaldehyde (C) Benzoic acid (D) Phenol [IIT 1991]
Q.3
Q.4
[IIT 1992]
Q.5
An organic compound C 3 H 6 0 does not give a precipitate with 2,4-Dinitrophenyl hydrazine reagent and does not react with metallic sodium. It could be: [ITT 1993] (A) CH 3 CH 2 CH0 (B) CH3COCH3 (C) CH2=CH-CH2OH (D)CH 2 =CH-0-CH 3 Under Wolif Kishner reduction conditions, the conversions which may be brought about is? (A) Benzaldehyde into Benzyl alcohol (B) Cyclohexanol into Cyclohexane (C) Cyclohexanone into Cyclohexanol (D) Benzophenone into Diphenylmethane [IIT 1995] In the reaction, Pis [IIT 1995] P + Se + I^O (B)CH 3 COOCH 3 (C) CH 3 C0CH 2 0H (D) None
Q. 6
Q.7
CH3 \
CH (A)CH3COCHO Q.8
(A) the attack of OH" at the carbonyl group (B) the transfer of hydride to the carbonyl group (C) the ab straction of proton from the carboxylic acid (D) the deprotonation of Ph-CH,OH Q. 9
[IIT 1996]
Among the given compounds, the most susceptible to nucleophilic attack at the carbonyl group is (A) MeCOCl (B)MeCHO (C) MeCOOMe (D) MeCOOCOMe [IIT 1997] Q 10 In a Cannizzaro reaction the intermediate which is the best hydride donor is: [IIT 1997] H
O"
fa Bansal
Classes
Carbonyl Compound
[21]
Q. 11 Q. 12
> CH 3 - CH = N - OH. The above reaction occurs at: (B) pH = 4.5 (C) Any value of pH (D)pH=12
[IIT 1997]
Q. 13
Among the following compounds, which will react acetone to give a product containing > C = N (A)C 6 H 5 NH 2 (B)(CH 3 ) 3 N (C) C 6 H 5 NHC 6 H s (D) C 6 H s NHNH, [IIT 1998] The product obtained via oxymercuration (HgS0 4 -H 2 S0.) of 1 -butyne would be O || (A) CH 3 CH 2 - C - CH 3 (C) CH 3 CH 2 CHO + HCHO (B) CH 3 CH 2 CH,CHO (D) CH 3 CH 2 COOH + HCOOH [IIT 1998]
Q. 14 Q 15 Q 16
Which of the following will undergo aldol condensation: (A)Acetaldehyde (B) Propanaldehyde (C) Benzaldehyde Which ofthe following will react with water: (A)CHC13 (B)Cl 3 CCHO (C)CC14
[IIT 1998] (D) Trideutero acetaldehyde [IIT 1998] (D) CICH2CH2CI [IIT 1998]
A new carbon-carbon bond formation is possible in (A) Cannizzaro reaction (B) Friedel-Crafts alkylation (C) Clemmensen reduction (D) Reimer-Tiemann reaction The enol form of acetone, after treatment with D 2 0 gives: OD I (A) C H , - C = CH 2 O II (B) CD 3 - C - CD 3
Q 17
[IIT 1999]
Q. 18
Which of the following has the most acidic hydrogen: (A) 3-hexanone (B) 2,4-hexanedione (C) 2,5-hexanedione The appropriate reagent for the following transformation:
v
Q. 19
/V ch3
H 0
C I L 2 C I 1 3
J.
(B ) H H 2 NH 2 , OH
A mixture of benzaldehyde and formaldehyde onheating with aqueous NaOH solution gives: (A) benzyl alcohol and sodium formate (B) sodium benzoate and methyl alcohol (C) sodium benzoate and sodium formate (D) benzyl alcohol and methyl alcohol [ IIT 2001 ] Compound A (molecular formula C 3 H 8 0) is treated with acidified potassium dichromate to form a product B (molecular formula C^H^O). B forms a shining silver mirror on warming with ammonical silver nitrate. B when treated with an aqueous solution of H 2 NCONHNH 2 . HC1 and sodium acetate gives a product C. Identify the structure of C. (A) CH 3 CH 2 CH = NlN'HCONH2 (B) CH , - C = NNHCONH, i CH 3 (C) C H 3 - C = NCONHNH 2 CH, (D) CH 3 CH 2 CH-NC0NHNH 2 [IIT2002] ISJ
Q.21
(!Bansal Classes
Carbonyl
Compound
/CHO
OHCN
( O \ (i)NaOH(excess)100C (ii)H+/H20
Q.22
' Q
\
s
[IIT 2003]
CHO
OHC /
(A)
COOH HOOC
CH 2 OH
COOH
(C)
OX
COOH CH 2 OH
Q.23
OCOCH3 ^OCOCH,
Acidic Hydrolysis
[IIT 2003]
The order of reactivity of phenyl Magnesium Bromide with the following compounds is [IIT 2004]
A
(I)
C H
H,C
A
(IT) >
Ph
A
(Til)
Ph
Q.25
MeO
[IIT 2005]
MeO
(D) CHO-COOH
Q.26
The smallest ketone and its next homologue are reacted withNt^OH to form oxime. (A) Two different oximes are formed (B) Three different oximes are formed (C) Two oximes are optically active (D) All oximes are optically active [JEE 2006]
faBansal Classes
Carbonyl Compound
[23]
C . H . O H and heat
(d)
| ITT 1995]
=Q
C)kcn/h2s4
(ii)LiAlH4
>D.
[IIT 1996]
Q. 3
Acetophenone on reaction with hydroxylamine-hydrochloride can produce two isomeric oximes. Write structures ofthe oximes. [IIT 1997] An aldehyde (A)<CuHgO), which does not undergo self aldol condensation, gives benzaldehyde and two mole of (B) on ozonolysis. Compound (B), on oxidation with silver ion, gives oxalic acid. Identify the compounds (A) and (B). [IIT 1998] (a) Write the intermediate steps for each ofthe following reaction. (i) C6H5CH(OH)C=CH > C6H5CH=CHC:HO (ii) (b) Show the steps to carry out the following transformations. (i) Ethylbenzene benzene (ii) Ethylbenzene - 2-phenylpropionic acid
HI(excess).heat
Q.4
Q.5
[IIT 1998]
Cf CH3
Q. 6
(CH3)2CHOCH3
(A) + (B)
[IIT 1998]
Q.7
(C)
J^xhc6H5
\J
^)LiAlH
(ii)H+,heat
[IIT 1998]
Q. 8
[IIT 2000]
^Ph
Q. 9
[IIT 2000]
0
-> A + B L f C (C 7 H ] 2 0) Q. 10 (i) (ii) (iii) (iv) Five isomeric para-disubstituted aromatic compounds A t o E with molecular formula C 8 H g 0 2 were given for identification. Based on the following observations, give structure of the compounds. Both A and B form a silver mirror with Tollen's reagent; also, B gives a positive test with FeCl3 solution C gives positive iodoform test. D is readily extracted in aqueous NaHC0 3 solution. E on acid hydrolysis gives 1,4-dihydroxybenzene. [IIT 2002] Classes Carbonyl Compound [24]
faBansal
[IIT 2002]
q
r A
O
CH2CH2CH3 Cl2/FeCl3^A_NgL^B HN0 3 / H 2 S 0^
CH=CHCH.,CrNa +
^D-
H2/Pd/C
Q.12
(C)
I Ale. K H ^ ^ O
ozonoi sis
ozonolysis ^ ^
(A) y (F) + (G) NaOH ) HCOONa + 1 alcohol (D) is isomer A. E gives negative test with Fehling solution but gives iodoform test. F and G gives Tolleris test but do not give iodoform test. Identify Ato G [IIT 2003] Q. 13 An organic compound (P), C 5 H u ,0 reacts with dil. H 2 S0 4 to give (Q) and (R). Both (Q) and (R) give positive iodoform test. The reactivity of organic compound (P) is 1015 times more than ethylene with [IIT 2004] respect to dil. H 2 S0 4 . (i) Identify the compounds (P), (Q) and (R). (ii) Give reason for the extraordinary reactivity of compound (P).
-X
(i)O,
(ii) Zn / CHjCOOH
.Y NO aH
[IIT 2005]
Q. 15 Which of the following disaccharide will not reduce Tollen1 s reagent? CH2OH
^
[IIT 2005]
CH2OH
9 /H H\ J
^ ^
CH2OH
oho
(a)
(b)
OHJO H K HK HC
H OH H O
. HOH2C
OIOH Xonm
H H OH
OH H
OH H
(P)
fa Bansal
Classes
Carbonyl Compound
[21]
ANSWER
KEY
EXERCISE-I(A)
Q.l
C A B C A B B B
B B B A D D C
C B C C D D B
A C D B A C B
D B C C C D C
B A D D D C A
EXERCISE-KB) Q.l Q.5 Q9 Q.13 Q.17 Q.21 Q.24 Q.26 C,D Q.2 B,C Q.3 Q.6 A,B,C,D A,B,C Q.7 Q.10 B,C A,B,C,D Q.ll D Q.14 A Q 15 B,C,D Q.18 A,C,D Q.19 A,C,D Q.22 A,B,D Q.23 Q.25 (A) P, R, (B) P, (C) S, (D) Q,S (A) P, (B) Q, (C) S, (D)R EXERCISE-II A,C,D Q.4 A,B Q.8 B,D Q.12 Q.16 A,B,C Q.20 A,B,C A,D (A) P, (B) Q,S, (C) S, A,B B,D A A,B A,D (D) P
Q.l
(a) CH 3 -CH2-CH 2 -OH (c) CH 3 -CH 2 -CH 2 -0H OH (e) CH3 - CH 2 - CH - C = CH (g) CH 3 - C H 2 - C H - O C H , OH
H
(i) CH 3 -CH 2 -CH-NH-PH (j) CH 3 - CH 2 - CH - N - CH , CH 3 (k) C-C-C=N-OH (m) CH 3 -CH 2 -CH 2 (o) semi carbazane OH (q) CH 3 - C H 2 - C H - C N (r) CH 3 -CH 2 -C0 2 H (1) CH 3 -CH 2 -CH=N-NH 2 (n) p-Nitro phenyl hydrazon (p) CH,- CH 2 -CH=CH-CH 3
l&Bansal
Classes
Carbonyl Compound
[26]
o Q.2 (a) C-C-C-C-OH (b) CH, - CH 2 - CH 2 - CH = C - CH 2 - CH , OH (c) C - C - C - C = N - O H (d) C - C - C - C - P h OH (e) Ph - CH = C - CH 2 - CH 3 I CHO (0 C - C - C - C H - C = CH CHO
(k)
2 alcohol
(1) CH 3 - C H 2 - C H 2 - C H - C H - C 0 2 E t Et
Q.3(a) 3 > 2 > 1 > 4 OH i Q 3(b) (I) (CH 3 ) 2 CCN OH (ii) C 6 H 5 CCN CH 3 Q.4 Q.6 R-Mg-X (a) C H 3 - C H - N H - C H 2 - C H 2 - O H CH, O (c)CHCl3 + ^ ^ - C - O H (b)
Q.7 Q.8
HO/Br2
H2 / N i ;
NaOH
(a) (i) KMn0 4 , (ii) CH 2 - OH , (iii) LiAlH4, (iv) H 3 0 CH2-OH (b) (i) CH 2 - O H , (ii) NaBH 4 , (iii) H 3 0 + , (c) (i) CH 2 - O H , (ii) PH 3 P=CH-Et CH2-OH (d) (i) H 2 , (ii) Ni; (e) (i) H2s (ii) Pd-C ; NH. CH2-OH (f) NaBH 4 OH (B) Me 2 CH - CH 2 - CH - CN
Q. 10
(A) Me 2 CH - C H . - C - CN H
faBansal Classes
Carbonyl
Compound
[23]
OH Q.ll (A) CH 3 - C - C H 3
CN
OH
(B)CH3-C-CH3
CO2H
( C ) C H 3 - C = CH 2
Q.12
(a) (X) |
CH,^
C
(B)
C-CH 3
U CH,
a
fO
cr
CH
CO2H
o <b)
Ph - PH
CO,H M:O,H
Q.16
(A)
(B)
(C)
CHJ-CHJ-CN
(D) f
>-C-C-C02H
Q.17
(b)CH 3 MgBr/ H \ A
CH3 o
(0
Q.l
faBansal Classes
Carbonyl
Compound
[23]
Q.4
(A)
(B)o:
(oH0Oo
Q.8
OH I CHI CH 2 CH 2 O I CH 2 ? I CL IO ( a &(3)
Q.9
(A) C-C=C-C-C
(B) C - C - C - C - C O
Q.10
(E) C - C - C - C - C (F) C - C - C - C - C il 0 Empirical formula of (A) = 0 ^ 0 ; Molecular formula of (A) = CFIjO HCHO CH 3 OH HCOOK HCOOH Methanal (A) (B) (C) (D) EXERCISE-IV (A) Q.5 Q.12 Q.19 Q.26 D A,D B B Q.6 Q.13 Q.20 D A A Q.7 A Q. 14 A,B,D Q.21 A
A A B,D D
D D B C
B B B C
l&Bansal Classes
Carbonyl Compound
[29]
EXERCISE-IV
(B)
Q. 1
Q 2
/"
CH2NH2
and
Q.4
[Ol
X )
fO f
^
+
C 0 0 H
(B) Q.5 (a) (i) C 6 H 5 CH(OH)OCH C 6 H 5 CH-C = CH OH^ C6H5CH=CHCHO v TautomerisatioiT C6HSCH=C= CH OH
+
'CH,
C H
Q.6
1\ _ >HOCH3 3 CH,/'
uv , HI e ess) ^ Af
CHC 6 H 5
Q.7
>
(C)
(D)
faBansal Classes
Carbonyl Compound
[23]
Q.9 (A)
CH3 C-CH 3
o
Br2+NaOH ^ f
Q.10
(A) ( O ) OCH3
( B ) [ 0 ] OH
OH NO,
Q.ll
(A)
(C) c r y
C1
(D) v_ f c\-
O-CH 2 -CH=CH 2
(E)
O-Pr
Q. 12
CI (C)
NaOH ^
H C O O N a + M e g C - C H j O H (lalcohol) CH 3 Q.13 C
5
1 0
Ois
H 2 c <
/\
C H 3
CH, ^ O R H-
CH.
CH 3 I x+ H3C 0'
CH, CH 3
H,0
)H3C"
"O
+ C2H5OH
^Bansal
Classes
Carbonyl Compound
[31]
(X) Q . 15 In structure (P) both the rings are present in acetyl form therefore it will not hydrolyse in solution that why Fehling solution cannot react with this. In structure (Q) one ring present in the form of hemiacetal. This will hydrolysed in solution it can reduce Fehling solution.
fa Bansal Classes
Carbonyl Compound
[21]
I BANSALCLASSES
*
ORGANIC CHEMISTRY
XII (ALL)
EXERCISE
-1(A)
Q.l
Q.2
(i)Bf2/K0H
(ii)ir
(B)C6H5COOH
CH 3 MgBr
) C H 4
+ ( A }
^ (ii)H20/H
( B
RCOOAg >R-Br which one of the following acid will give maximum yield ofR-Br in the above reaction? (A) CH3 - CH - COOH CH3 CH3 (C) C H 3 - C - C O O H CH3 Q. 5 Q.6 Benzoic acid on treatment with hydrazoic acid in the presence of concentrated sulphuric acid gives: (A) Benzamide (B) Sodium benzoate (C) Aniline (D) C6H5CON3 The given reaction C2H5 CH3-C-COOH C3H7 is called: (A) Schmidt reaction (C)Hofinann rearrangement
I N,H/Conc.H,SO,
r l
<fIBansal Classes
Page # 2
Q.7
In the reaction sequence: CH3 - CH - COOH [ Y ] OH [Y] will be: (A) CH 3 -CH-C=0 OH (C) CH2 - CH2 - COOH (D) CH3-CH (B) CH2=CH-COOH n
o
CH-CH3
W o
Q. 9
Acetylation reaction with acetyl chloride is carried out in the presence of which solvent? (A)HOH (B)CH3OH (C) Pyridine (D) NaOH
O
C6H5 H
" St?
C H
6 5 ~C-CH2-C6H5
(B) (C 6 H 5 -CH 2 C0) 2 0 (D) C6H5-CHC12 > Aspirin (B) o-methoxybenzoic acid (D) /?-Hydroxybenzoic acid
[X] will be: (A) CgHsCHjCOCl (C) Both (A) and (B) Q.ll In the given reaction: [X] + Acetic anhydride [X] will be: (A) Benzoic acid (C) o-Hydroxybenzoic acid
Q.12 The given reaction is: C6H5-CHO + C6H5CHO (A) Claissen reaction Na2[Fe(C0)4] > C6H5 fi-0-CH2C6H5 (D) Cannizzaro reaction
Bansal Classes
Page #3
Q.13
[X]
C-CH2-C-CH3 H
Q.14
Number of cross products in the given reaction: CH3COOC2H5 + C 6 H 5 -CH 2 -COOC 2 H s (A) One (B) Three
c
2h5HL C 2 H 5 OH
(C) Two
(D) four
Q.15
Hofmann degradation is given by: (A)Imide (B) Acid chloride In the given reaction: O C6H5-C-N [X] will be: 'CH3 -CH3 L,MH4
)[X]
Q.16
Q.17 Which one of the following compounds gives carboxylic acid with HN0 2 ? O (A)C6H5-C-C1 (C) C H 3 -0 - O - C - C H 3 C fl (B) C6H5CONH2 (D) CH3COOC2H5
fe Bansal Classes
Page #4
Q .18
H2 /Hffi
> Product
(C) Mixture of CH3 - C - COOH and HOOC - C - CH3 H OH (D) C H 3 - C H - C O N H 2 Q.19 In the given reaction: CI CH3 - CH - COOH Product [X] will be: (A) a-Amino acid Q.20
(l)NHs
Imole (ii)H20
> [X]
(B) a-Aminoamide
(D) 3-Aminoamide
(B) CH 3 -CHO + Br-CH 2 -COOC 2 H, X (C) CH 2 - CH 2 - COOH (D) All of these Q. 21 Rochelle salt is dimetal salt of: (A) Tartaric acid (B) Citric acid
NaOH/HOH
(i)Zn
(ii ) N H 4 C l / H O H (iii)HOH/H / A
< f I B a n s a l Classes
Page # 5
Q.22
(B)
-(C) L O J ^
>
(D)
CQC
Q.23
(A)C 6 H 5 ONa
)[pT
(C)[pJ
(D)(cTpC00Na
Q.24
(B) Aspirin
Arrange these esters in decreasing order of ease of esterfication with CH, OH/H: (I) CH , - CH - COOH i CH, CH 3 (III) CH, - C - C O O H CH 3 (A) 11 > 1 > III > IV (B) I > II > 111 > IV (C) III >IV > II > I (D) IV > 111 > II > I (IV)(CH,-CH 2 ),C-COOH (II) CH 3 - CH - CH 2 - COOH I CH 3
Q.26
Arrange following compounds in decreasing order of reactivity for hydrolysis reaction: (I)C 6 H 5 COCI (II) N O 2 - { O ) - C O C I O (NI)CH3-/R)YCOCI (A) II > IV > I > III (B) II > IV > III > I (IV)OHC-\OVC-CI (C) I > II > III > IV (D) IV > III > II > I
<fIBansal Classes
amines
Page # 6
Q.27
VKOH
(ii)NH3/A (C) Propylamine (D)Acetamide (D) 5-Hydroxy acid (D) 5-Bromo acid (D)Adipicacid
Which one of the following on heating gives unsaturated acid: (A) a-Hydroxy acid (B) P-Hydroxy acid (C) y-Hyroxy acid Which will form lactone on treatment with NaOH? (A) a-Bromo acid (B) p-Bromo acid (C) P-Hydroxy acid Which one ofthe following will go decarboxylation on heating? (A) Succinic acid (B) Phthalic acid (C) Malonic acid In the given reaction: CHJ-COOH 6 [X] will be: /COOH (A) CH,.
(ii)NaCN
(L)BF2/P
> [X]
(iii)H20/H/A
^COOH
CH2-CO\^
Q. 3 2
Which optically active compound on reduction with LiAlH4 will give optically inactive compound? (A) CH3 - CH - COOH OCH 3 (C) CH3 - CH 2 - CH - COOH CH 2 OH (B) CH3 - CH 2 - CH - COOH OH (D) CH3 - CH - CH 2 - COOH
OH
Q.33
O
CH 3 - CH - C - CHR - CH, , 2 3 [X] will be: CF3CQOOH . * [X] as main product
O II
(A) CH3 - CH 2 - C - O - CH - CH3 CH 3 CH 3
O II
(B) C H 3 - C H - C - O - C H 2 - C H 3
0
(C) CH3 - C - OC(CH3 ) 3 (fe Ban sal Classes (D) (CH3)3COOCH3 Page # 7
Q. 3 4 Which one of the following reactions can be used for the preparation of (3-hydroxy acid: (A) Perkin reaction (B) Reformatsky reaction (C) Aldol condensation '(D) Claisen condensation Q.3 5 Which acid can be oxidised be Fehling solution: (A) Malonic acid (B) Acetic acid (C) Oxalic acid Q.3 6 In the given reaction:
COOH
[X]
COBr
COOH Br
OOH
COOH
CJ
O II
(C)
(D)
O II
'
(C)-C-OH
O A o
CH,
+ [X]
[X] will be: OH (A) HOOC-CH2-CH2-CH -CH 3 (C) HO-C^-CI^-CI^-COOH (B) CH3-CH2-CH2-CH2-COOH (D) CH3 - CH2 - CH - CH2 - COOH OH
Bansal Classes
Page #8
Q.3 9
* > [A]
I t)H
and CH 2 OH - CH, - CH 2 - CH - CH 2 OH OH o J
OH
A
(C) Both are I
COC 2 H 5 + I
cooc
H H N o
(A)[
H
7 I
(B)kN>0 H
/COOC2H5 "N=Cv-C00C2H5
N=c
/COOC2H5
CH 2
(C)[
^OOC 2 H5 -NHO
(D)CH 2 v
M r iN =
/COOC2H5
^-COOC^Hg
^B ansa I Classes
Page # 9
CH,-COOH CH2-COOH
(B) will be:
(A)-
CH,-CH,NH,/A
>(B)
O
(A) CH 2 -C-NH-C 2 H 5
O I!
(B)CH2-CCH, - C
2
N-COH5 2
^
o
CH,-COOH (C) CH,-COOH
II o 0
(D) I CH,-COOH
Fenton
>
( B )
(B)RCOOAg CH3
(C) CH3-CH3
Q. 44
Sodium benzoate on heating with sodalime gives: (A) Benzene " (B) Benzophenone (C) Methane
Q.45 Which of the following compounds gives carbondioxide with NaHC03? (A) Acetic acid (B) Hexanol (C) Phenol (D) Acetylene Q.46 When propanoic acid is treated with aqueous sodium bicarbonate, carbon dioxide is liberated. The carbon of the C0 2 comes from: (A) Methyl group (B) Carboxylic group (C) Methylene group (D) Bicarbonate Q.47 The reduction of benzoyl chloride with Pd and BaS04/CaC03 produces: (A) Benzyl chloride (B) Benzoic acid (C) Benzaldehyde (D) All of these Q 48 Which one of the following esters cannot undergo self Claisen condensation? (A) CH3-CH2-CH2-COOC2H5 (B) C6HsCOOC2H5 (C) C 6 H n -CH 2 -COOC 2 H 5 (D) C6H5-CH2COOC2H5 Q. 49 Amides may be converted into amines by a reaction named after: (A) Kekule (B)Perkin (C)Hofmann Bansal Classes (D) Claisen Page #10
Q. 5 0 The treatment of an ester with LiAlH4 followed by acid hydrolysis produces : (A) Two aldehyde (B) One carboxylic acid and one alcohol (C) Two alcohols (D) Two acids Q. 51 Which of the following is hydrolysed to give secondary amine:
<jj
(A) Alkyl cyanide (C) Nitro paraffins Q.52 N-Ethyl pthalimide on hydrolysis gives: (A) Methyl alcohol (B) Ethyl amine Q.53 Which amine will not react with nitrous acid: (A) Methyl amine (C) Dimethyl amine (B) H - C - N ' (D) Acid amide
.CH3 -CH3
Q.54 Which gas will be evolved out when [CH^O-LNT^ + (CH3)2CHNH2] is treated with sodium nitrite and HCl: (A) Chlorine (B) Ammonia (C) Nitrogen (D)N0 2 Q.55 Boiling Ethylamine on reaction with acidified KMn04 gives: (A)Acetaldehyde (B) Ethanoic Acid (C) Ethanol (D)Acetamide
Q. 5 6 Methyl amine on reaction with chlorine in the presence ofNaOH gives: (A) Chloroform (B) Methyl chloride (C) N-Methyl chloramine (D) Chloramine Q.57 Highest value ofpKb will be of: (A)NH3 (B)(CH3)2NH (C)(CH3)3N (D)CH3NH2
Q.58 Lowest boiling point will be of the compound: (A) Ethylamine (B)Ethylmethylamine (C) 1-Propaneamine (D) N,N-Dimethylmethaneamine Q.59 Amines are basic in nature because: (A) They produce OH ions when treated with water (B) They have replaceable H atoms onN atoms (C) They have 1 one pair of electron on N atom (D) None of these Q.60 Which of the following diazonium salt is relatively stable of 0-5 C: (A) CH3-N=N}C1(B) CH3C(CH3)-N=N}C1(C) C6H5-N=N}CL (D) (CH3)3C-N=N}C1Q. 61 Alkylamine dissolve in hydrochloric acid to form alkylammonium chloride. The nitrogen in the latter salt is: (A) Quadricovaient only (B) Tricovalent only (C) Unielectrovalent only (D) Quadricovaient, Unielectrovalent Q.62 Which of the following can be detected by carbylamine reaction: (A) Urea (B) CH3CONH2 (C) C ^ N f ^ Bansal Classes (D) All of above Page #11
Q.64 Hydrolysis ofalkylisocyanide yields: (A) Primary amine (B) Tert. amine
Q. 6 5 Which of the following compound gives the smell of mustard oil: (A) Alkyl isocyanate (B) Alkyl isothiocyanate (C)Alkylisocyanide (D) Alkyl isonitrile Q. 66 The compound obtained by the reaction between primary amine and aldehyde is: (A) An amide (B)lmine (C) Nitrite (D) Nitro Q. 6 7 When propionamide reacts with Br2 in the presence of alkali the product is: ( A) CH3CH2CH2NH2 (B)CH3CH2NH2 (C)C3H7CN (D) C2HsCN Q.68 A reaction of ethyl amine & acetic anhydride leads to the formation of: (A) CH3NHCOCH3 (B) C2H5CONHCH3 (C) CH3CONHC2H5 (D) CH3-CH=NOC2H5 Q.69 Identify X in the reaction
CI
COOH
heat
300K
NH2
NC
NH2
J
CI
(B)0
COOH
(C,0
CI
( D
, 0
CI
C6H5-NHX
Q.70
g
cone HC1
> A +
fi
C6H5-NH^
Heat
The unknown compounds A and B in the above reaction are: (A) Phenyl mercaptan and aniline (C) C6H5-N=C-S and C6H5 NH3} CI Q.71 Aniline with solid KOH and CS2 gives: (A) Thiourea (B) Phenyl thio urea
CH3MgBr
(D)Diphenyl thiourea
Q
Q.72 r V c N zH ^A W I Zis: /
H3O
>X
O
(A) [ C - CH3 (B) [ > C O O H
(C)
Bansal Classes
Page #12
Q.73 V
Y < ^ ^ - < f Q V c O O H
(")KOD,Br 2 A
(i)N 3 A
(ii)KOH,Br 2 A
'
(A) X is
Yis
( O ^
2
Major end product of the following sequence of reaction is: CH3CH2CH2CONH2 (A) CH3CH2CH2NH2 (C) CH3CHCH3 OH
ea(OH) 2 > CI 2
) X
J !
N O
> Z
Q. 75
The bond angles in methane (I), ammonia (II) and trimethyl amine (III) increase in the order: (A) I >111 >11 (B) I >11 >111 (C) II > I > III (D) III > II > 1
Q.76 Name the products in the acid-base reaction: (a) CH3CH2NH2+ HI (b)(CH3)3N + HBr (A) (a) Trimethyl ammonium iodide (B) (a) Ethyl ammonium iodide (C) (a) Ethyl ammonium iodide (D) All of these
(b) Trimethyl ammonium bromide (b) Methyl ammonium bromide (b) Trimethyl ammonium bromide
Q. 77 Acetic anhydride and ammonia gives the product: (A) CH3C0NH2 (B) CH3CONHCH3 (C) CH3CN
(D) CH3COONH4
<fIBansal Classes
Page # 13
Q. 78
The artificial sweetener aspartame (A) is converted to time in aqueous solution: ^ Q H3N-CH-C-NH-CH-C-OCH3 CH2 CH 2 Ph (A) O O I! II (A) H 2 N - C H - C - N H - C H - C - O C H 3 CH 2 CO. CH 2 Ph
+ CH3OH
() AL
Q. 8 0
( ) Lh C nJ U
The synthetic sweetener aspartame, known commercially as Nutra sweet, is carboxylic acid. In aqueous solution on standing it changes to:
(AA
>
//
/F NH
(C) \\
<fIBansal Classes
Page # 14
EXERCISE - KB) Q. 1 Consider the following statements regarding the following reaction: QHXHO 6 5
(CH,CO), O 3 2 CH3COONaA
>
H,-0 2
(A) Acetate ion acts as base in this reaction (B) The anhydride having atleast one a-hydrogen, provides an enolate for the reaction (C) The acetate deprotonates the anhydride to form the nucleophile needed for the reaction '(D) EtONa can also be use as base Q.2 Which of the following will liberate C0 2 on reaction with NaHC03 (A) ( 0 ) ^ (C)
O H
CVO CH-CH2OH T Y 4h
HO HO
Q.3
RCOOR1 can be prepared by: (A) esterification of RCOOH (B) esterification of (RC0) 2 0 (C) Baeyer-Villiger oxidation of RCOR' withperoxy acid (D) reaction of RCOCl with R'OH In the Hofinann bromamide degradation recation ? R - C - N H 2 + KOH + Br2 Intermediates are: (A) RCONHBr > (C) RNHj (D)None
Q.4
(B)RNCO
Q.5
C4HJJN + HN0 2 > C,H]0O (3 alcohol) (X) hence X will give: (A) carbyl amine reaction (B) Hofmann mustard oil reaction (C) diazonium salt (as the intermediate) withHN02 (D) base insoluble product with Hinsburg reagent Mixture of 1, 2 and 3 amines can be separated by: (A) Hinsberg's method (B) Hofinann's isocyanide test (C)fractionaldistillation (D) NaN0 2 HCl
Q.6
Bansal Classes
Page #15
Q.7
>ONH
CI
(B) y ^ C l + 2NH3
> y m i 2 + NH4C1
Which of the following compounds will give acetic acid with KMn04/H/A: (A) CH3-CHO (B)CH3-CH=CH-CH3 (C) CH3-C=C-CH3 (D)CH3CH20H Acetic acid can be used for the preparation of: (A) Ethane (B) Methane (C) Acetone (D)ethanol
Q.9
Q.10 Which one of the following acids will form acetyl chloride with PC15? (A) MeCOOH (B) MeCOOMe (C) MeCOOCOMe (D) Me-CONE^ Q.ll Consider the following reaction: CH3-C-OH+CH3-QH
H
> CH,-C-O-CH3+HOH
ff
True about the above reaction is: (A) Product is having smell like fruits (B) Nucleophilic addition followed by elimination reaction (C) folio ws A ac , mechanism (D) it is irriversible reaction Q.12 In the given reaction: RCOOAg + X2 R - X + C 0 2 + AgX X2 can be: (A) Cl2 (B)Br2 (C)I 2 Q.13 Which one of the following compounds will give HVZ reaction?
COOH -COOH
(D)F2
(C) / - C O O H
Q.14
Sodium salt of which one of the monobasic acids on electrolysis does not give hydrocarbon: (A) C6H5COOH (B)HCOOH (C) Me3C-COOH (D) COOH-CH=CH-COOH Carboxylic Acids & It's Derivative Aliphatic amines Page # 16
<fIBansal Classes
Q.15 Which one of the following acids undergoes decarboxylation on strong heating: (A) Pyruvic acid (B) 3-butenoic acid (C) Formic acid (D) Salicylic acid Q.16 Which one of the following compounds is least reactive with water?
o
(A) CH3 - C - CI
o
(D)C6H5-C-C1 (D)Anticeptic
(B)C6H5-C-NH2 (C)CH3-C-NH2
Q.17 Acetic anhydride is used as: (B) Dehydrating agent (C)Acetylating agent (A) Solvent Q.18 In the given reaction:
O I I
[X]
(B)CH3OH/H
Q.19 Which of the following gives silver mirror test? (B) CH3COCHOHCH3 (A) HCOOH (D) Glucose (C) Tartaric acid Q.20 An example of a primary amine is: (A) n-Propylamine (B) Isopropylamine Q.21 Which compound is soluble in water: (A)[(CH3)2NH2]+C1(C)[(CH3)3NH]'CT (C) t-Butyl amine (B) [CH3NH3] CI (D)PhN0 2 ~ (D) CH3N+H3C1" (D) Sec. butyl amine
Q.22 Which compound will liberate C0 2 from NaHC03 solution: (A)CH3CONH2 (B) CH3NH2 (C) (CH3)4N+OH~
Q. 23 Which of the following compound can be produced if 1 -propane amine is treated with NaNO, and HCl (A) Propane-l-ol (B) Propane-2-ol (C) 2-Chloropropane (D) 2-Propaneamine Q. 24 Which of the following amine does not react with Hinsberg reagent to give base soluble product (A) Neopentvl amine (B) secpropyl amine (C) diethyl amine (D) Ethyl methyl amine Q 25 Ethylamine can be prepared by (A) Curtius reaction (B) Hofinann reaction (C) Mendius reaction (D)Reduction offormaldoxime Q.26 The presence of primary amines can be confirmed in laboratory by: (A) Reaction with HN0 2 (B) reaction with CHC13 and ale. KOH (C) Reaction with Grignard reagent (D) Reaction with acetyl chloride
Bansal Classes
Page #17
Q.27
Select correct statement (s): (A) Cyclohexanone is oxidised to caprolactone which is hydrolysed under the reaction conditions (B) Baeyer-Villiger oxidation involves migration ofH/alkyl/aryl groups which is in order H > tert-alkyl > sec-alkyl > phenyl > primary alkyl > methyl (C) Pinacolone (CH 3 ) 3 CCCH 3 is oxidised to t-butyl acetate by C 6 H 5 C0 3 H O (D) All of the above are correct statements
Q.28
(C) 0 Rv.
Q.29
/OH 1 1 (a weak acid) is formed O Column I (organic compounds oxidised by HI0 4 ) (A) CH 3 COCHO (B) 1,2-cyclohexanedione (C) PhCH (OH) CHO (D) CH 3 CH 2 CH (OH) COCH 3 (D) Column I (A) C 6 H 5 - C - OC 2 H 5 + H 3 C - C - 0 - C 2 H 5 -> II " II o o C 6 H 5 - c - CH 2 - c - O C 2 H 5 + C 2 H 5 O H II II
Column II (products of H I 0 4 oxidation) (P) PhCH = O + HCOOH (Q) CH3CH2CHO + HOOCCH 3 (R) HOOC (CH 2 ) 4 C00H (S) CH 3 COOH + HCOOH Column II (P) AnhydrousZnCL
Q.30
(B) H 3 c - C - OH + Cl2 o
C1CH2-C-OH o
(Q)
C 2 H 5 0,e
(R)
Red P
CH3
amines
Page # 18
Q 31
Column I (Reagents reacting with PhCH 2 COOH) (A) CH 3 MgBr (B) PC15 (C) NH 3 , followed by heating (D) CH 3 OH in the presence of conc. H 2 S0 4 Column I (Reactions) 0 (A) 2CH 3 CH 2 NH 2 + 0
Column II (Product formed) PhCH 2 COCl (P) (Q) PhCH 2 COOCH 3 (R) CH 4 ' (S) PhCf^CONHj Column II (Products)
Q 32
(P)
(oVN-CH-ZO)
o II S
(B)
(CH 3 ) 2 NH + C 6 H 5 COCI
(Q)
(CH 3 ) 2 N
m
o
(C)
CHO + ^ ( J ^ - N H a
(oV
(R)
o II (CH 3 ) 2 N-C
S0 2 C1
(S)
C 2 H 5 NH - c - CH 2 CH 2 - C - O Column II
^+HC1 >
PhN(CH 3 ) 2 RR'NH 2
Column I (A) PhCONH 2 > PhCH 2 OH O (B) 0 CM, (C) C 6 H 5 CH = C H - COOH ->C 6 H 5 - CH = CH 2 OH (D) CH3COCI CH 3 -CHO CH 2 OH-(CH 2 ) 2 -CHOH-C 6 H 5
Q 35
(ii)H20
HYDF0LYSIS
amines
Page # 19
.....etc.
Q.2
Ester (A) B
+C
aqKOH
(CH 3 ) 2 CHCH 2 OH
NaN02+HCl / p \
Q.3
R-COOH
(A)
Br,,KOH
>(B)
Q.4
Mo stAg2
'
KCN
H^O
soci.
Q.5
- >C
^^
E+NaCl
Q-6
[ ZCO'n > - M ^ r
.ci
CO\
A.
PCI,
MeNH, v> C L
o /NH2
+
/NH-C-Me
+
Q.7
O= <
A - ^ O- ^ c
B>0
(unede)
/NHSO3H o = <
Q.8
CaCN 2 +
H O H - i ^ ( A ) - ^ ^ ^ ( B )
(H 2 0 2 )
a
Q.10 Q.ll
p h
COOH
>A
_A_>B +B
NTOOH A H A
COOH
/ = ^ .
C 0
0 H
-U(
4 I B a n s a l Classes
Carboxylic
Q.12
PhMe + (A) p - M e C ^ - C Q - C H ^ a ^ C O O H
Zn/Hg/HC1
>(B)
Q.13
CH 3 (CH 2 ) 1 4 CH 2 CH 2 COOH
> (A)
CH 3 (CH 2 ) 1 4 COOH
(i)Ag+(ii)Br
2 >(D)
Q.14
[ p T
C 0 0 H
(A)
Hd
) (R)
_ic
L >
C H 2 C 0 0 H f^n Y-^CH.COOH
+ C02+H20
COOH
qi5
l
O
COOH
Q.16
CI
OH"
>(A)
/ a\
OH" .
>(B)
(i)H 2 0 (II)H30
Q.17
HC=CH
^ 2 N a > (A)
(ii)2C0 2
2/Pd
BaS0 4
Q, 18 Q.19
>D
>E
(CH3CO)2O
A
) F
o Q.20
^^^ )
LiA1H4
CH3-C-N~(
> (A)
o Q.21 [ P l y o
0 LlA1H
" ) (B)
Q-22
R-C-NH2+
"
>R-NH 2
Q.23
4IBansal Classes
Page #21
RON,
Q.25
R - C - O H + HN3 o
II A,CI
ff
2s4
>RNH2
o
II
Q.26
R-C-Cl
)R-C-C6H5
Q.27
O R - C - CI + CFLN2 >
(ii)H20
R-CFL-COOH
Account for following: Q.28 Fluoro acetic acid is stronger than chloro acetic acid. Q.29 C-0 bond length in formic acid are 1.23 A and 1.36 A but in sodium formate both carbon and oxygen bonds have same value i.e. 1.27 A. Q.30 Acetic acid can be halogenated in presence of phosphorous and chlorine but formic acid cannot be halogenated in the same way, Q. 31 The C-G bond in acid derivative is expected to be shorter and stronger than alkyl derivative. Q. 3 2 An acyl chloride undergoes nucleophilic attack more rapidly than does an alkyl halide. Q. 33 Primary and secondary amide exist as dimer in solid and pure liquid state. How will you bring about the following transformation: Q.34 Propanoic acid into lactic acid. Q.35 Nitroethane to acetic acid. Q.3 6 Benzoic acid to benzamide. Q.3 7 Ethyl benzene to 2-phenyl propionic acid. Q.38 Acetamide from acetone. Q.39 Tartartic acid from ethylene. Q.40 Lactic acid from acetic acid. Q.41 Pyruvic acidfromethyl bromide. Q. 42 p-hydroxy propionic acidfromethylene oxide.
1
^Bansal Classes
Page # 22
EXERCISE - III Q. 1 (a) (b) (c) (d) (e) Show by a series of equations how you could synthesize each of the following compounds from the indicated starting material and any necessary organic or inorganic reagents. 2-Methylpropanoic acidfromtert-butyl alcohol 3 -Methylbutanoic acidfromtert-butyl alcohol 3,3-Dimethylbutanoic acidfromtert-butyl alcohol H02C(CH2)5C02H from H02C(CH2)3C02H 3-Phenyl-1-butanol from CH3CHCH2CN
/Br
(f) I A
CO2H
from
cyclopentyl bromide
rr"
(S) Q.2 L /L N
C02H
from
(E)-C1CH=CHC02H
M e
TR^O I >CH2COOH
Suggest a reasonable mechanism for this reaction. What other organic product is also formed? Q.3 Suggest reaction conditions suitable for the preparation of compound Afrom 5-hydroxy-2-hexynoic acid. CH3CHCH2C = CCO2H > OH 5-Hydroxy-2-hexynoic acid Q. 4 (a) r v H,}"
0 0
Compound A
O O
A + BrMgCH9CH7CH,CH,MgBr
"
(ii)H,0
HC xCH2CH2CH2OH
n
Q. 5 (a)
ya
O
C H 3 0 ^ ~ ^ ~ CC1 +
fe Bansal Classes
Page # 23
o
(b)
o
CH3 Mgl (1 equiv) diethyl ether
> c o m p ( ) u n d
CH3CCH2CH2COCH2CH3 -
( a l a c t o n G ;
C^O,)
o
(c) HOC
COH
heat
Q.6
An organic compound C4H604 (A) when heated with acetic anhydride give another compound C4H403 (B) which in turn react with ammonia to give a third compound C4H502N (C). Both (B) and (C) may be hydroiysed to A. With chlorine A give monochloro-compound (D) which reacts with caustic potash to give either C4H405K2 (E) or C ^ O ^ (F) depending upon the condition of reaction. Identify the compound A to F. An organic compound A (C4Hc,NO) on treatment with bromine and alkali form another compound B (C3H9N) on treatment with sodium nitrite and dilute hydrochloric acid. B yield C (C3HgO). C can be oxidized to D (C3H60). Which can also synthesisedfrommethyl acetylene. Identify the compound Ato D. With bromine and caustic potash the straight chain compound C4H9ON (A) give C3H9N (B), with caustic soda C4H702Na (C) and with phosphorous pentoxide gives C4H7N (D). With hydrochloric acid D give C4H802 (E) ofwhich C is the sodium salt. B may be converted to an alcohol (F) and then to a halide the grignard reagent from which react with carbon dioxide to give E. On oxidation F give. Identify the compound Ato H. Compound (A) with an empirical formula, C7Hc,N on diazotization give a product which undergoes reaction with Cu2Cl2 & HC1 to give a compound (B). B on oxidation give a compound (C). Compound (A) on treatment with Br2/H20 form C7H6NBr3 (D). Give the structural formula ofA, B, C & D.
Q.7
Q.8
Q. 9
Q.10 An organic compound A (C3H5N) on boiling with alkali give ammonia and sodium slat of an acid B (C3H602) A on reduction give a compound 0 (C3H9N) which with nitrous acid give D (C3HgO). Give the structural formula ofA, B, C and D. Q.ll An organic compound (A) C3H?ON on heating with POCl2 give a compound B which on hydrolysis give a compound (C) C3H602 with the liberation of ammonia. Compound Aon treatment with LiAlH4 form compound C3H9N (D). Compound D treating with HN0 2 liberate N2 gas on refluxing with chloroform and alcoholic KOH give compound E which have foul smell. Identify compound A,B, C, D and E.
Q. 12 An organic compound A (C8HgO) an treatment with NH2OH. HC1 give B and C. Compound B and C can be converted into D and E respectively by treatment ofH 2 S0 4 . Compound B, C, D and E are all isomer of molecular formula CgF^NO. When D is boiled with KOH, and oil F (C6H7N) separate out. F react rapidly with CH3COCl to give back (D). On other hand. E on boiling with alkali followed by acidification give a white solid G (C7H602). Identify Ato G. Q.13 An organic compound A, (CgH9NO) on heating with conc. H 2 S0 4 give another isomer of (A) i.e. (B) C8H9NO. Compound B on hydrolysis with dil HC1 give an aliphatic acid C, C2H402 and (D) on treatment with NaN02 HC1 at 0C give a compound (E) which give a white ppt. of AgCl on addition of AgN03. Compound (E) react with alkaline (3-naphthol to produce orange dye what are to E. Q.14 An organic compound A of the molecular formula C4Hg03 give effervescence with sodium bicarbonate solution and can be acetyl ated. It can be separated into dextro and laevoisomers on heating it forms an acid B with formula C4H602. Compound B give positive Bayer's test. Identify A and B. fe Bansal Classes Carboxylic Acids & It's Derivative Aliphatic amines Page # 24
Q.15
An aromatic compound A, CgH5N02 can be condensed with an acid derivative (B) C 7 H,,0 4 Br in presence of alkali to form compound (C), C15H15N06. Compound (B) can be prepared by action of sodium followed by bromine gas on diethyl malonate. Compound (C) condensed again with ethyl chloro acetate in presence of sodium to give compound (D) C19H21N08. D on heating with a base can be converted into E and a salt of acid F (CgH604). Compound A can be obtained by heating F with ammonia. E on boiling with mineral acid produce amino acid G (C4H7N04). Identify Ato C.
Q.16 An organic acid A(C3H403) is catalytically reduced in presence of ammonia to give (B) C3H7N02. B react with acetyl chloride hydrochloric acid and alcohol. It can also react with nitrous acid to give another compound (C) C3H603 along with evolution of N2. What are (A), (B) and (C)? Q.17 A dibasic acid (A), C4H606, on heating with KHS04 give a monobasic acid (B), C3H403, with the elimination of C0 2 and H 2 0. Acid (B) on reduction give another monobasic acid (C), C3H603. Both (B) and (C) on heating with I2 and NaOH solution give yellow precipitate of iodoform and sodium oxalate. Acid (A) react with two moles of acetyl chloride, while (C) reacts with one mole of acetyl chloride. Acid (A) reacts with four moles of HI to form succinic acid, while (C) react with two moles of HI to give propionic acid. Identify A, B, C and give equation for reaction. An organic compound of the formula C3H60 (A) gave iodoform test but not Tollen's and Fehling tests. Two molecules of (A) condenes in presence of dry HCl gas to yield (B) of formula C6H10O. Compound (B) decolourised Br2/CCl4 and cold dilute neutral KMn04, but no ppt. with ammonical AgN03 or CuCl solution. It gave iodoform test and potassium salt of a compound on heating with I2 and KOH. The potassium salt on treatment with H 2 S0 4 gave compound (C) of formula C5H802. Compound (C) on heating with sodalime gave (D) of formula C4Hg. Identify compound Ato D & write the chemical equation.
Q.18
Q.19 An organic compound (A) of formula C3H6Qfroma monoxime with hydroxylamine and form iodoform on heating with I2 and NaOH and sodium acetate. Compound A on reaction with NaCN and dil. H2S04 gave product B. Which on hydrolysis produced (C). Compound (C) on heating gave (D), which on decarboxylation gave (E) of formula C3H6. Compound (E) on ozonolysis gave one molecule of acetaldehyde and one of methanal. What are Ato E? Q.20 Two moles of an ester (A) are condensed in the presence of sodium ethoxide to give a P-keto ester (B) and ethanol. On heating in an acidic solution (B) gives ethanol and J3-keto acid (C). On decarboxylation (C) gives 3 -pentanone. Identify (A), (B) and (C) with proper reasoning. Name the reaction involved in the conversion of (A) to (B). Q.21 An acidic compound (A), C4Hg03 loses its optical activity on strong heating yielding (B), C4H602 which reacts readily with KMn04. (B) forms a derivatives (C) with SOCl2, which on reaction with (CH3)2 NH gives (D). The compound (A) on oxidation with dilute chromic acid gives an unstable compound (E) which decarboxylates readily to gi ve (F), C3H60. The compound (F) gives a hydrocarbon (G) on treatment with amalgamated Zn and HCl. Give structures of (A) to (G) with proper reasoning.
Q. 22 An organic compound (A), C5H803 on heating with soda-lime gives (B),which reacts with HCN to give (C). The compound (C) reacts with thionylchloride to produce (D), which on reaction with KCN gives compound (E). Alkaline hydrolysis of (E) gives a salt (F), which on heating with soda-lime produces -butane. Careful oxidation of (A) with dichromate gives acetic and malonic acid. Give structures of (A) to (F) with proper reasoning. Q.23 An acid (A), C g H ? 0 2 Br on bromination in the presence of FeBr gives two isomers, (B) and (C) of formula CgH602Br2. Vigorous oxidation of (A), (B) and (C) gives acids (D), (E) and (F) respectively. (D), C7H502Br is the strongest acid among all of its isomers, whereas (E) and (F) each has a molecular formula of C7H402Br2, Give structures of (A) to (F) with justification. Carboxylic Acids & It's Derivative Aliphatic amines Page # 25
fe Bansal Classes
EXERCISE - IV (A)
O
Q.l
The reaction of
R-C-NH 2 with a mixture of Br2 and KOH gives R-NH2 as a product. The [BIT 1992] (C)R-NHBr (D)R-C-N<
(B)R-N=C=0
II
Br
Which ofthe following carboxylic acids undergo decarboxylation easily: (A) C6H5CO-CH2COOH (B) C6H5COCOOH (C) C6H5CH2-COOH OH
[IIT 1995]
.1
Q. 3
The molecular weight of benzoic acid in benzene as determined by depression infreezingpoint method corresponds to : [IIT 1996] (A) Ionization of benzoic acid (B) Dimerisation of benzoic acid (C) Trimerisation of benzoic acid (D) Solvation of benzoic acid When propionic acid is treated with aqueous NaHC03, C0 2 is liberated. The 'C' of C0 2 comes from (A) Methyl group (B) Carboxylic acid group (C) methylene group (D) bicarbonate [IIT1999] Benzoyl chloride is preparedfrombenzoic acid by: (A) Cl2, hv (B)S02C12 (C)SOCl2 [IIT 2000] (D^HJO
Q.4
Q.5 Q. 6
Which of the following acids has the smallest dissociation constant? [Ill 2002] (A) CHXHFCOOH (B) FCH2CH2COQH (C) BrCH2CH2COOH(D) CH3CHBrCOOH
^OCQCH3
P
v
Acidic
Hydrolysis
ProductsformedbyP&Q can be differentiated by [IIT2003] (B) Lucas reagent (ZnCl2)conc. HC1 (D)Fehlings solution [IIT 2004] (D) Benzylamine
Whenbenzamid is treated withPOCl3, the product is: (A) Benzonitrile (B) Aniline (C) Chlorobenzene
Which of the following is obtained when 4-Methylbenzenesulphonic acid is hydrolysed with excess of sodium acetate? [IIT 2005] (A)CH3-<fy-COONa (C) CH3 ~ f V s o r 3N a +CHXOOH S0 Na + CHgCOOH (B) CH3 (D) CH, CH3 7 + S0 3 ^\- S 0 2 0 . COCH3 + NaOH
fe Bansal Classes
Page # 26
Q.10 The correct IUPAC name of C6H5G0C1 is (A) Benzoyl chloride (C) Benzene carbonyl chloride Q.ll
[IIT 2006]
Which ofthe following reactants on reaction with conc. NaOH followed by acidification gives the following [IIT 2006] lactone as the only product?
O
\> / CH 7
<a
Q.l
COOCH3
COOH
<b>OC
\
COOH CHO
COOH
c c
cc
COOH
EXERCISE - IV (B) Compound (A) (C6H1202) on reduction with LiAlH4 yielded two compounds (B) and (C). The compound (B) on oxidation gave (D) which on treatment with aqueous alkali and subsequent heating furnished (E). The latter on catalytic hydrogenation gave (C). The compound (D) was oxidised further to give (F) which was found to be monobasic acid (molecular mass = 60.0). Deduce the structure of (A), (B), (C), [IIT 1990] (D)and(E). In the following reactions, identify the compounds (A), (B), (C) and (D) PC15 + S0 2 ->(A) + (B) (A) + CH3COOH > (C) + S0 2 + HCl 2(D) + CdCL 2(C) +b (CHACd Complete the following equations by writing the missing A and B CH,CH,COOH
;f2 >
Q.2
[IIT 1994]
Q.3 (i)
[IIT 1995]
(A)
(i)Alc.KOH(excess) (ii)H
(g)
(ii) Q.4
C4H03(A)
(B)
A mixture of an acid anhydride (A) and a monobasic acid (B) on heating produces another monobasic acid (C) of equivalent weight 74 and an anhydride (D). The acids and anhydrides remain in equilibrium. The anhydride (D) contains two identicalfluoro-alkylgroups. The acid (B) contains a trifluoromethyl group and has an equivalent weight of 128. Give structures of (A) to (D) with proper reasoning. (Atomic weight of fluorine =19). [HT 1998] Identify Aand B in the following equations: [IIT 1999]
Q.5
H3C^^cooc2H5
CH \COC2H5
o
.(B)
(i)OH~ (ii)H + A
.(A)"
CH--C-OH 2
II o
fe Bansal Classes
Page # 27
Q.6
Q. 7
Identify X, Y and Z in the following synthetic scheme and write their structure. Explain the formation of labelled formaldehyde (H 2 C*0) as one of the products when compound Z is treated with HBr and BaC*0 3 +H 2 S0 4 >C (gas) [C* denotes C14] [IIT 2001] CH2 = CH - Br 2
( )Mg/ether
'
(II)X (iii)H30+
Q. 8 Q.9
Mention two esters pro duced when a racemic mixture of 2-phenyl prop anoic acid is treated with (+) 2-butanol. What is the stereochemical relationship between these esters? [IIT 2003] Give major products A, B, C and D in following reaction sequence.
CH2-C1
[IIT 2004]
f /-N 1
( )
KCN DMF
V A
(i)NaOEt/EtOH (ii)PhCHO/ A
>n n
H,0
socl2
(ii) CH 3 NH 2
Page # 28
ANSWER KEY EXERCISE -1(A) Q.l Q.8 Q. 15 Q.22 Q.29 Q.36 Q.43 Q.50 Q.57 Q.64 Q.71 Q.78 C D A B D B A C A A D C Q.2 Q.9 Q.16 Q.23 Q.30 Q.37 Q.44 Q.5I Q.58 Q.65 Q.72 Q.79 B C D B C B A B D B C C Q.3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 Q.52 Q.59 Q.66 Q.73 Q.80 C c B A A A A B C B A C Q.4 Q.ll Q.18 Q.25 Q.32 Q.39 Q.46 Q.53 Q.60 Q.67 Q.74 B C C A C A D D C B C Q5 Q.12 Q.19 Q.26 Q.33 Q.40 Q.47 Q.54 Q.61 Q.68 Q.75 C B A A A B C C D C A Q.6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 Q.55 Q.62 Q.69 Q.76 A C A A B B B A C D C Q.7 Q.14 Q.21 Q.28 Q.35 Q.42 Q.49 Q.56 Q.63 Q.70 Q.77 A C A B D C C C A C A
Q.l Q.5 Q.9 Q.13 Q.17 Q.21 Q.25 Q.29 Q.30 Q.32 Q.34
EXERCISE - KB) Q.4 A,B,C,D A,B Q.2 A,B,C B,C Q3 Q.8 A,B,C,D A,C,D Q.6 A,B,C A,C Q7 Q.12 A,B A,B,C,D Q.10 A,B,C Q.ll A,B Q.16 B Q.14 B,C Q.15 A,B,C,D B,C Q.20 A,B,C,D Q.18 A,B,D Q.19 A,B,C,D A,B,C Q.24 A,B Q.23 A,B,C Q.22 D A,B,C Q.28 B Q.26 B Q.27 D A,B,C (A)S,(B)R,(C)P,(D)Q (A)Q, (B)R,(C)P,(D)S Q.31 (A) R, (B) P, (C) S, (D) Q (A)Q,(B) S, (C)P,(D)Q Q.33 (A) S, (B) Q, (C) P, (D) R (A)S,(B)Q,(C)S,(D)R Q.35 (A) P, (B) R, (C) P,S, (D) Q
EXERCISE - II (A) CH3CH(OOCCH3)2; (B) CH3CHO; (C) (CH 3 C0) 2 0 (A) (CH3)2CHCOOCH2CH(CH3)2 ; (B) (CH3)2CHC0C1; (C) (CH3)2CHCH2C1 (A) RCOND2; (B) RNH2; (C) ROH (A) CHgCl; (B) CH3OH; (C) HCOOH; (D) Ca(OH)2; (G) HCHO; (H) CH3C1; (I) KCN; (J) CH3CN; (X)CH 3 COOH (A) CH3COOH; (B) CH3COONa; (C) CH3COCl; (E) (CH 3 C0) 2 0 (A) HOOCCH2CH2COOMe; (B) C10CCH 2 CH 2 C00Me; (C) MeNH0CCH 2 CH 2 C00Me (A) 2NH3; (B) CH3COCl; (C) H 2 S0 4 + S0 3 O
^NHCH-, \ NH"
Q.8
"C ft o II
[
Q.9
(A)k
;(B)[
Q. 10(A)
H M
rooH S
COOH
Ph-
(B)
Q 11
(A)
.00
Q.12
(A)
Q.13
(A) CH 3 (CH 2 ) ]4 CH 2 CHBrCOOH; (B) CH 3 (CH 2 ) 14 CH=CHCOOH; (C) KMn0 4 ; (D)CH 3 (CH 2 ) 14 Br
Q14 ( A
> tOXc,oH;
1
00H
(B
>
^lcH2cr(C)
L
H
CN
^ o t -(D) tOD 1
:c=o
Q.l 5(A)
;(B)
COOH
COOH
Q.16
(A)
COOH H
;(C)
COOH
Q.17
H - C - C O O H ; (C) H-C-COOH
^
H COOH'
(D)
N^T+COOH
H
XTH-CO^
^ H
C 0
Q.18
(D)[0
ONH 4
-ONH4 ;(E)
y N-H
Q.19
(F)
Me
H'
CH 2 OH
Q.20
(A)CH 3 CH2NH-
CH 2 OH
CH 2 COOH Q.6 (A) CH 2 COOH Succinic acid (E) CH 2 (OH)COOK CH 2 COOK Q.7 Q.8 (F) (B)
CH2CO\
p
CH2CO/ Succinic anhydride CHCOOK CHCOOK Potassium maleate
(D) I
CH 2 CICOOH CH 2 COOH
(A) (CH 3 ) 2 CHCONH 2 ; (B) (CH 3 ) 2 CHNH 2 ; (C) (CH 3 ) 2 CHOH; (D) CH 3 COCH 3 (A) CH,CH 2 CH 3 C0NH 2 ; (B) CH 3 CH 2 CH 2 NH 2 ; (C) C ^ C ^ C H ^ C O O N a ; (D) CH 3 CH 2 CH 2 CN (E) CH 3 CH 2 CH 2 COOH; (F) CH^CHjCI^OH ; (G) CH 3 CH 2 CHO; (H) CT^CH^COOH NH 2 CI (B)fOl CH, CI .(C) [ O
Q.9
) f O L CH,
COOH
Q.10 Q. 11
(A) CH 3 CH 2 CN ; (B) CH 3 CH 2 COOH; (C) CH 3 CH 2 CH 2 NH 2 ; (D) CH^CHjCHJOH (A) CH 3 CH 2 CONH 2 ; (B) C 2 H s CN; (C) C 2 H 5 COOH; (D) C ^ C H ^ ^ N F ^ ; , (E)CH 3 CH 2 CH 2 N = C
amines
Page # 30
0 Q.12 (A)
CH,
CH3OH
;(D)
O |f>rNH-C-CH 0 II C-OH
C-CH3 ; ( B ) r f ^ r C = N - O H c ) r ^ [ - C = N ;(
(E)
Q.13 (A)^Q
(G)
o II N H - C - C H 3 ; (C) CH3COOH;
(E)FO
Q.14
2Cr
Q 15 (A)
N_H;
^N-CH(COOEt) 2 ;
COOEt -CCHXOOEt. COOEt Q.16 Q.17 Q.18 Q.19 Q.20 Q.21 Q.22
(A) CHJ = C(OH)-COOH; (B) CH^CCNH^-COOH; (C) CH3CH(OH)-COOH CH(OH)COOH (A) ] ; (B) CH3-CO-COOH; (C) CH,-CH(OH)-COOH CH(OH)COOH (A) CH3-CO-CH3; (B) (CH3)2C=CHCOCH3; (C) (CH3)2C=CHCOOH; (D) (CH3)2C=CH2 (A)CH3-CO-CH3; (B) (CH3)2C(OH)CN; (C) (CH3)2C(OH)COOH; (D) CH2= C-(CH3)-COOH (E) CH3-CH=CH2 Claisen condensation, (A) C2H5COOC2H5; (B) C2H5COCH(CH3)COOC2H5; (C) C2H5COCH(H3)COOH (A) CH3CH(OH)CH2COOH; (B) CH3CH=CHCOOH; (C) CH3CH=CHCOCl (D) CH3-CH=CHCON(CH3)2; (E) C^COCH^COOH; (F) CH3COCH3; (G) CH3CH2CH3 (A) CH3-CO-CH2CH2-COOH; (B) CHgCOCK^CT^; (C) CH3C(OH)(CN)CH2CH3 (D) CH3C(C1)(CN)CH2CH3; (E) CH3C(CN)2CH2CH3; (F) CH3C(COONa)2CFL,CH3
fVVrCH2COOH 2
Q.23 (A) [ O I R r Br
; (B) B r j O J - B r
(7-OpCH 2 COOH
i (9 f O
2rnOH
-Br
' (D)[UJ-Br
iV^VCOOH
(E)
O
Br
-COOH -Br
(F)
lOjBr Page # 31
Q.l Q.8
A,B A
Q.2 Q.9
A C
Q.3
Q.6
Q.7
Q. 1
(A) C H ^ C f ^ C O O C f ^ C H , ; (B) CH 3 CH 2 QH; (C) CH 3 CH 2 CH 2 CH 2 OH; (D) CH 3 CHO; (E) CH 3 CH= CHCHO Q.2 (A) S0C12; (B) P0C1 3 ; (C) CH 3 C0C1; (D) CH 3 COCH 3 Q.3 (i) (A) CH 3 CHBrCOOH; (B) CH 2 = CHCOOH; (ii) (A) CH 3 CH(OH)CH2COOH; (B) CHjCOCF^COOH Q.4 (A) (CH 3 CH 3 C0) 2 0; (B) CF 3 CH 2 COOH; (C) CH 3 CH 2 COOH; (D) ( C F ^ C O ^ O HC-(COOC2H5)2 Q. 5 Q.6 Q.7 (A) NaCH(COC 2 H 5 ) 2 ; (B) CH 3 - HC - COOC 2 H 5 (A) CH 3 COOH; (B) C 2 H s 0 1 8 H BaC*0 3 + H 2 S 0 4 > C*0 2 (X) + BaS0 4 CH 2 =CH-Br
(i)Mg,(ii)C*Q 2 (iii)H30+
LiA1H
^
4 >
H+
>
> C* H 2 CH=C*H 2
I Br iBr CH 2 =CH-C*H 2 Br BrCH2 - C H ^ C * ^ I 0 3 ZNH 2 0 I O ^ n f ^ O Br-C*H 2 CHO + HCHO Br-CH 2 CHO + HC*HO
H Ph H ' (+)CH3CH2-C-OH
Q.8
I I CH3-C-COOH + CH3-C-COOH
| ~ |
CH,
conc.H2S04,A
H (racemic mixture)
Ph
H H I I CH3-C-C-O-C-CH2CH3 I II I Ph O CH 3
during esterification reaction only -COOH and - O H partcipates. There is no effect on structure or configuration of carbon adjacent to these groups. So when() acid reacts with pure (+) alcohol two esters are produced which are diastereoisomers of each other. CN 9VCN CH=C^O) COOH CH=C-(p) CONHCH3 CH = C
Q.9
<A)(g)
( B ) ^
(Ofgs
( D ) ^ ^ ,
amines
Page # 32
ORGANIC CHEMISTRY
XII (ALL)
CONTENTS
EXERCISE-I EXERCISE-II EXERCISE-III EXERCISE IV ANSWER KEY
EXERCISE-I
(Choose the correct option. Only one is correct) Q.l I XH
>
(A>
\/\/
Q A
C , < X > c d
<$2
Cf)
(D)CH 2 =CH
sj^. 3
2-chloropentane on halogenation with chlorine gives 2,3, dichloropentane. What will be the structure of free radical species form in the reaction? (A) Planar (B) Trigonal planar (C) Square planar (D) Pyramidal What will be maj or product, when 2-methyl butane undergoes bromination in presence of light? (A) 1 -bromo-2-methyl butane (B) 2-bromo-2-methyl butane (C) 2-bromo-3-methyl butane (D) 1 -bromo-3-methyl butane The smallest compound, which on photochlorination produces diastereomers is (A) 3-methyl, 3-chloro hexane (B) 2-chloro butane (C) 1 -bromo propane (D) 1 -bromo-3-methyl butane
Q.6 Q.7
Which ofthe following will give two isomeric monochloro derivatives? (A)2,3-dimethylbutane(B)n-hexane (C) Isopentane (D) Butane How many isomers can be producedfromthe molecular formula C4H10O? (A) 8 (B)7 (C)6 (D)5 Et~
Cl-v
> 1116 ma or
Q. 8
J P roduct i s
EtO
Cl-\
(A)
HO
t
OEt
(B)
EtO
t
OH
(C)
[\*
(D)
O
OEt
Ph J&
^ CT
L>CH3
3
H3O+
(B)
I HO^YCHA
OH
^Bansal
Classes
Halogen Derivatives
[2]
* /^v-OH ^0710 I J
(A)
(B)
(C)
(D)
OH
Among the given compounds, the correct dehydration order is: a ) O O H (A) I < I I < I I I < I V Q.12 ( i i ) P O (iv) (D) I < II < III = IV
Br, CC1-
> y
alc.KOH A
> z
H,C(A)
3
CH, ( B ) H HO
3
C - ^ OH
( C ) H
C ^ CH
( D ) H
C - ^ CH2
Q.13
>product
tt/
(A)
c=C
C1F2CX
.OEt
CIF2CV
/ F
C1F2CX
/ F
/=C Ph
(B)
F
J>C PhX
OEt
(C)
p h
> - 9 Ph I
F
(D)
OEt
>
<
X
(l5
|\:H 3
O ^ S .
CHs
H+
C H
(A)
k X !
(D)
0 H
^ A x
C H 3
faBansal Classes
[3]
Q/T6 HBr reacts fastest with ^ (A) 2-methyl butane-2-ol (C) Butane-1 -ol Q.17
-ex
[
,COCH3
NaOBr
)
The product is
o
CH,
<oc
nu
o c ~ o .
/OH
'OH
Which one of the following alcohol will undergo acid catalysed dehydration with greatest ease by E, mechanism? (A)CH2 = CH-OH (B)!"] T OH (C) OH (D)Me2CHOH
0C2O
(A) C 3 H 6 0
NaCN
H 2 SO 4
> cyanohydrin of (A). Ifthe cyanohydrin is optically active, then the possible
1 Which ofthe following has minimum reactivity towards nucleophiles? (A) CH20
X I L L ROH/H+
(B) CH3CHO
O II
O II
sj^.22
J)
(q
QH3
OR
(d)
0
[4]
^Bansal Classes
Halogen Derivatives
Q.23
In addition of HOBr to (I) and (II) (A) Br is at C2 in both cases (C) Br is at C, in II and C2 in I 4 Greatest amount of hydration is in (A)[^| y
(C) [ ^ B r "
Q.25
^ (A)\
^Br J
1 equivalent Mg ether
> X
>
Y; Y is
(B)\
(C)\
How many number of optically active isomers are possible for 2,3-dibromo butane 1,4-dioic acid? (A) 2 (B) 3 (C)4 (D)l ~K Q-27 < yN and \ n-^
Are which type of isomers (A) Chain (A) Eclipsed form (B) Position (B) Staggered form (C) Metamerism (C) Skew form (D) functional (D) None of these Most stable conformation of ethylene glycol Which has maximum B.P.? H3C
( ^ H ^ C / ^ ^ ^ v /
0 1 1 3
.CH, CH3
^ .CH,
(B).
H3C
H3CV
H3CV
(C)H3c^/CH H3C
x &30
(D) H V
H 3
Which of the following carbocation is most stable? ( / C a z I CH3 (A) A H3C S CH, (C) /K/0** V HO
3
faBansal Classes
[5]
(A)
A
H
( B )
A
'OH
( O h , C ^
(D)
^CH
CH3SN/CH3
CH3XN/CH3
C H
3 \
(a)
fo)
<b) f o J C H 3
(c)
(o)
(D)
[ o
CH3
3 In which ofthe following molecule all the effect namely inductive, mesomeric & hyperconjugation operate
( A ) < ^ - C 1 (
B
) \ _ / " CH3
C H
( C ) ( > C O C H 3 CH,
(D)<
* >
>
+ C l e , AH + Cl , AH
^-CH + CI, AH3
^)-CH2CL
(IV) { >
C 1
> { ^ y + CI , AH
The correct decreasing order of enthalpies of reaction for producing carbocation is (A) AH > AH > AH > AH (C) AH > AHj > AH > AH Jtr (B) AH > AH > AH > AH (D) AH > AH > AH > AH
(B)2>1>3
(C) 2>3>1
(D)3>2>1
Halogen Derivatives
[6]
Q.36
One of the configuration of n-butane is drawn in the given figure. Anticlockwise rotation of C2 around C 7 -C, bond by 120 will lead to
CH3
(A) gauche
(B) staggerred
Which of following is correctly matched. OH (A) CH3 - C - CH 3 , E, reaction I CH3 OH I (C) CH3 - C - CH 3 , thermal reaction I CH3 8 (B) CH3-CH2-CH2OH, E,cb reaction
Arrange reactivity ofgiven alcohol in increasing order of elimination reaction (I) CH2 - CH2 - CH2 - CH2OH I NO2 (III) CH3 - CH - CH 2 - CH2OH I NO2 Select answerfromcodes given below: (A) I, II, IV, III (B) I, II, III, IV
p.
t-
Arrange leaving power ofNu group in decreasing order O eff (I) o - S - C 6 H 4 - C H 3 (II) O - S - C 6 H 5 O (A) II, I, III, IV O (B) II, I, IV, III (C) I, II, IV, III (D) I, II, III, IV
(III) N 3
(IV) Br
^J^/40
Arrange decreasing order of reactivity of these compounds for nucleophilic substitution reaction O II (I) CH3 - CH2 - O - S - CF3 o (III) CH3 - CH - CH3 OH (A) III, IV, I, II (B) III, IV, II, I (IV) CH3 - CH - OH C6H5 (C) I, II, III, IV GOC (D) I, II, IV, III [7]
tBansal
Classes
X^41
X 3 < H
(A)
HOv /
H
H 3 + O H
A
H\
'
/
A i S
X^_y\H
Ph
\ 7CH3
(B)
\ /CH3
Q.42
CH3
CI.
Ph
alc.KOH
A, A is
ch3^C6H5
(A)
H
^C6H5
(C)
CfiH<
^C6H5
Q.43 Major product obtained in reaction of 1 -phenyl-2-bromo butane with NaOMe. (A) (E)-l-phenyl but-l-ene (B) (E)-l-phenyl but-2-ene (C) 1 -phenyl-1 -ethoxy butane (D) (Z)-1 -phenyl but-2-ene Q.44 2-Aminocyclohexane-1 -ol on treatment with HN0 2 produces (A) Cyclopentane carboxaldehyde (B) Cyclo hexane-1,2-diol (C) 2-amino cyclohexene (D) Cyclohex-2-enol 5 Arrange the following in order of C-Br bond strength in polar solvent.
o<i
46 CI
o c
Oc.
RateR
(C) IV<III<II< I
<-Qc
EtOH
OEt
s /
EtOH
Rate R2
EtOH
>
vX5
R-OEt
RateR3
(C)R2>R,>R3
Among the foloowing pairs in which case the second compound has higher heat of hydrogenation. (A) | ||, [ f ^ ] (B) Cis-2-butene,trans-2-butene
(C)
faBansal Classes
Halogen Derivatives
[8]
Q A ^ (I)
(A) I is more soluble than bromocyclopropane (B) I gives pale yellow ppt. on addition with AgN03 (C) I is having lower dipole moment than bromocyclo propane
/
-Br
Q.49
\^TC(CH3)3
CH3SNa
^0H > ?
The product formed is (A) CH3SCH, -CH-C(CH 33) 33 3 2 OH (C) CH3SCH2CH-C(CH3)3 OH (B) (CH 3 ) 3 C-CH-CH 2 OH ( SCH3 (D) (CH 3 ) 3 C-CH 2 CH~SCH 3 OH
Q.50
(C)3<4<1<2
1 Which of the following statement about the reactivity of 1 -chloro apocamphane toward AgN03 is true. (A) React by SN1 mechanism (B) React by SN2 mechanism (C) React by SNi mechanism (D) Does not react
Q.5 2 The resonance energy of following heterocycles is in the order (A) pyrole > furan > pyridine (B) furan > pyrole > pyridine y? ^ ^ ^ (C) pyridine > pyrole > furan (D) pyridine > furan > pyrole Arrange the following halide in decreasing order of SN1 reactivity.
(I)CH3CH2CH2a
(
)CH
=CHCHCH
( I ) C H 3 C 2 CCH 3
CI
(A) I > II > III (B) II > I > III (C> II > III > I
CI
(D) III > II > I
^Bansal Classes
Halogen Derivatives
[9]
EXERCISE-II
(iChoose the correct option. One or more than one are correct) O.l
v /f \ = / which is/are incorrect statements? P Q (A) P is cis- and Q is trans(B)PisZandQisE (C) P is R and Q is S (D) P and Q are having same structural formula
Q.2
(C) tautomerism
(D) geometrical
Q.3
(maleic acid) can form: CHCOOH (A) stereoisomer (B) geometrical isomer (C) position isomer Which can show tautomerism ? (A) (B)Ph-CH 2 -NO (C)
Q.4
m -
CH 3
(D)CH3-C-NH, o
CH 3
CH 3
Q.5
A
CH 3
\ /
A
CH 3
I II I and II are not (A) achiral-identical mirror images (C) geometrical isomers of each other Q.6
In which of following compound chiral center is not affected on heating. (A) CH, - CH - COOH OH (C) CH 3 - CH - CH 2 - COOH OH (B) ( \=0
S PCH 3 CH HOOC
Q.7
Which are correct statements? (A) methyl malonic acid is converted into propanoic acid on heating (B) succinic acid forms succinic anhydride on heating (C) 3-hydroxy propanoic acid forms Lactide on heating O (D) CH 3 - C - CH 2 COOH forms acetone on heating
Q.8
Select incorrect statements: (A) ( 5 > 0 H and y^OH both give colour with neutral FeCl3 solution
(B) 2-pentanone and 3-pentanone are metamers (C) product formed when benzaldehyde reacts with hydroxylamine shows optical isomerism (D) 1,2-dibromocyclohexane shows geometrical and optical isomerism. faBansal Classes
Halogen Derivatives
[10]
Q.9
C5Hg04 (A)
C 4 H 8 0 2 (B)
Sodahme
A
> (C)
C is hydrocarbon occupying 0.509 litre per g approximately. Hence A and B are: (A) methyl malonic acid, propanoic acid (B) succinic acid, succinic anhydride (C) Dimethylmalonic acid, 2-Methylpropanoic acid (D) Ethyl Malonic acid, Butanoic acid
O II oc
Q-io ch 3 -o^^CH-CH 3
3+ >
products can be: (Both stable & unstable form) (A) CH3CH(OH)2, CH3CH(OH)COOH (B) CH3CHO, CH3CH(OH)COOH (C) CH3CH2COOH, CH3CH2OH (D) CH3CH(OH)COOH, CH3CH2OH Q.ll Which are incorrect statements: (A) ^ ^ = 0 and 0=^ ) are enantiomers
O
CI
O . I I
CH3 are enantiomers
H CH2CH3 (C) Argol (sodium potassium tartarate) will show optical isomerism. (D) CH3CHO on reaction with HCN gives racemic mixture. Q.12 Which is/are less acidic than Benzoic acid? (A)CH3COOH (B)(0)"cooh
3
(C)\O/-C00H NO2
(D)H 2 0
Q.13
Which have active methylene group? (A) CH3 - C - CH2 - C - CH3 (B) CH3-CH2-NO2
o (C) C H 3 - C - C H 2 -O - 0 - E t C
Q.14
( O V
^Bansal Classes
Halogen Derivatives
[11]
Q.15
The unshared electron on the oxygen atom of an ether (basic centre) account for all the following except: (A) Combination C2H5N.
c,H 5
> 6=
F | B- F F
(B) Formation of oxonium salt with acids such as (C) Formation ofperoxides (explosive) (D) Chemical inactivity of ether Q.16
/ cr
Which ofthe following compounds yield most stable carbanion after rupture of (CJ-C2) bond: 0 (A) CH3 - C - CC13 (B) CH3 - C - CBr3
I I
I I
I I
1 2
1 2
1 2
Q.17
H
pyrrole (I) pyridine (II) which is/are correct statements ? (A) I is more basic than II (C) ID is more basic than II Q.18
aniline (III) (B) II is more basic than I and III (D) all are aromatic bases
Which is/are untrue statements)? (A) Protonation increases electrophilic nature of carbonyl group (B) CF3S03 is better leaving group than CH3S03 (C) Benzyl carbonium ion is stabilised by resonance
/OH
(D)CC13CH<"
^011
is unstable.
(A)<0)-Br
(C)|
Or-
(B) <^0)-CH=CH-CH 2 Br
(D)(>- B r
1 II (A) I & III are antiaromatic (C) II alone is aromatic Q.21 Which have acidic hydrogen? (A)CH3COOH (C) C H 3 - C - C H 2 - C N ^Bansal Classes
III
O iv
(B)(0>-<OH
(D) NaNH2 Halogen Derivatives [12]
Q.22
C-C and C=C bond lengths are unequal in: (A) benzene (C) 1,3 cyclohexa-di-ene
Q.23
Products formed when HC1 adds to 2,4- hexadiene is: (A) 4-chloro-2-hexene (B) 2-chloro-3-hexene (C) 2-chloro-4-hexene (D) 1 -chloro-2-hexene Which ofthe following may be classed as an electrophilic reagent? (A)BCI3 (B) N H ; (C)CH 3 (D)AlCi;
Q.24
Q.25
The acid strength of substituted carboxylic acids is known to be dependent on the nature and position of the substituent. In the following examples, an attempt has been made to arrange the acids in order of acid strength, the strongest first. One of the series is incorrect-which one? (A) CH3.CH2CH(Cl).COOH > CH3.CH(Cl).CH2COOH > CH3.CH2.CH2.COOH (B) NO2.CH2.COOH > HOCH2.COOH > CH3.COOH (C) Cl3C.COOH > BrCH2.COOH > FCH2.COOH (D) CH3.COOH > CH3.CH2.COOH > (CH3)3C.COOH Which of the following would not have a dipole moment? (A)CC14 (B)CH2C12 (C) trans-1,2-dichloroethene Which of the following structures represent the less stable tautomeric form? (D)C1C=CC1
Q.26 Q.27
(A)ch3ch2cK
F 8o c h ^ ^
H
1
.ch3
(B)
Qo
YH
C = C
H H
H(X
(D)
(A)
X I
H3CN H
3
(B)
H
3
u
C ^ CH3
(C)
C/
C = 0
( D ) H 3 C
Q.29
In tautomerism (A) a proton is moved around the molecule (C) no actual movement occurs Which species is not aromatic? (A)
(B) electrons are moved around the molecule (D) shift of double bond occurs
Q.30
O N
(B)O
(c)Cjn
(wt> N9
Q.31
Aromatic character is possible only when (A) six electrons are delocalized (B) the molecule is cyclic and planar having delocalized (4n +2)n electrons where n = 1,2,3.... (C) alternate sigma (a) & pie (TC) bond are present. (D) None is true Classes GOC m
6 Bansal
FXERC1SE-1II Q. 1 Arrange the following compounds in decreasing order ofKeq for hydrate formation. O
C 6 H 5 COCH 3 CI^O)C
C H
(!) o N02-<O>-^CH3 (3) ^Q.2 Arrange the following compounds in order of: Decreasing SN1 reaction rate: s f I <
Q
(2)
0
CH3^0>-C-CH3 >
Ph
1 CI (II[)
^ P h
Q
aD
av)
(b) Explain which of these reactions would have the faster rate? CH3 (i) CH3CH2CH2 + CH 3 N: CI ^J^A (a) (b) Q. 5 Q. 6 CH3 > or (ii) CH3CH2CH2
C1
+ CH 3 NH 2
>
Arrange the isomers of molecular formula C4H9C1 in order of decreasing rate of reaction with sodium iodide in acetone. Explain in which solvents these reactions are faster:
CH3 sr
(c)
Q.7(i)Choose the member of the following pairs of unsaturated hydrocarbons that is more reactive towards acid-catalysed hydration and predict the regiochemistry of the alcohols formedfromthi s compound. (a) (b) ^ ^ ^ or (I)
(c)
(n) (ID
Br
(II)
(I)
Jr
I or
(ii) Predict on the basis of cabocation stability, which member of each of the following pairs hydrolyses at the faster rate.
Br (b)
(a)
(I)
or I
(H)
or
Br
a)
(o[Q
Q. 8
(ii)
Assuming that cation stability governs the barrier for protonation in H - X additions, predict which compound in each ofthe pairs in parts (a) to (b) will be more rapidly hydrochlorinated in a polar solvent. (I) (II) (a) CH2 = CH2 or
Q .9
<o>
(O
or CH3 - CH - CH2 - CI CH3
Select the member of each pair that shows faster rate of SN2 reaction with KI in acetone. CH3-CH2-CH2-CH2-C1
(I) (II) CH3 - CH2 - CH2 - CI or CH3 - CH2 - CH2 - CH2 - Br (I) (II)
CH,
J0T CH3 - CH - CH2 - CH2 - CI or CH3 - C - CH2C1 CH3 (I) Br (d) CH3-CH2-CH2-CH-CH3 CH3 (II)
Br or CH3 - CH - C % CH - CH3
^Bansal Classes
Q.10 Select the member of each pair that undergoes SN1 solvoysis in aqueous ethanol more rapidly. CH3 ^iaf CH 3 -CH 2 -CH 2 -CH 2 -C1 or CH 3 -C-C1 ch3 CH2 = CH-CH 2 -C1 ch3 ^Jcf CH 3 -C-C1 ch3 .Br (d) Q.ll (a) (b) (c) (d) (e) (1) Q.12 Q T or r^YBT or CH3 - CH2 - CH2 - CI or CH3 - C - Br ch3 ch3
In each ofthe following indicate which reaction will occur faster. Explain your reasoning. CH3CH2CH2CH2Br or CH3CH2CH2CH2I with sodium cyanide in dimethyl sulfoxide. 1 -chloro-2-methylbutane or 1 -chloropentane with sodium iodide in acetone. Hexyl chloride or cyclohexyl chloride with sodium azide in DMF. Solvolysis of 1 -bromo-2,2-dimethylpropane or tert-butyl bromide in ethanol. Reaction of 1 -chlorobutane with sodium acetate in acetic acid or with sodium methoxide in methanol. Reaction of 1 -chlorobutane with sodiumagde or sodium p-toluenesulfonate in aqueous ethanol. Classify each of the following species as electrophile or nucleophile & explain your choice. (a)CH3C02(g)SiF4 (b)CH30(h)Br > H
0H
(d) CI G)Me2CH
Ca( H)2
(e) CMe3
(f):CCl2
^Q.13 <x^Q:l 4 (a) (b) (c) (d) ,(e) (f) (g) - (h)
Propene
" > I
)K
Of the following statements, which are true for SN2 reaction. Tertiary alkyl halides reacts faster than secondary. The absolute configuration ofproduct is opposite to that ofthe reactant when an optically active substrate is used. The reaction showsfirstorder kinetics. The rate of the reaction depends markedly on the nucleophilicity of the attacking reagent. The mechanism is one step. Carbocations are intermediate. Rate oc [Alkyl halides] The rate of the reaction depends on the nature of the leaving group.
l^/Q-1 5 Of the following statements which are true for SN1 reaction. (a) Tertiary alkyl halides react faster than secondary. (b) The absolute configuration of the product is opposite to that of the reactant when an optical active substrate is used. (c) The reaction shows first order kinetics. (d) The rate ofreaction depends markedly on the nucleophilicity ofthe nucleophile. (e) The mechanism is two step. (1) Carbocations are intermediate. (g) Rate oc [Alkyl halides] (h) The rate of the reaction depends on the nature of the leaving group. Halogen Derivatives [16] ^Bansal Classes
Q.16 Explain why CI - CH 2 - O - CH 2 - CH3 is hydrolysedmore rapidly than CH 3 - O - CH 2 - CH 2 - CI Q.17 Ifthe temperature is not kept below 25 C during the reaction ofprimary alcohols with p-toluenesulfonyl chloride in pyridine, it is sometimes observed that the isolated product is not the desired alkyl p-toluenesulfonate but is instead the corresponding alkyl chloride. Suggest a mechanistic explanation for this observation. Q.18 Because the SN1 reaction goes though a flat carbocation, we might except an optically active starting material to give a completely racemized. In most cases, however, SN1 reactions actually give more of the inversion product. In general, as the stability of the carbocation increases, the excess inversion product decreases. Extremely stable carbocations give completely racemic products. Explain these observation. Q.19 cis-1 -Bromo-2-tert-butylcyclohexane and trans-1 -bromo-2-tert-butylcyclohexane both react with sodium ethoxide in ethanol to give 1 -tert-butylcyclohexene. The cis isomer reacts much more rapidly than the trans isomer. Explain. Q.20 The reaction of an amine with an alkyl halide gives an ammonium salt. R:>N: + R'-x > R3N -R'Xamine alkyl halide ammonium salt The rate of this SN2 reaction is sensitive to the polarity of the solvent. Draw an energy diagram for this reaction in a nonpolar solvent and another in a polar solvent. Consider the nature of the transition state, and explain why this reaction should be sensitive to the polarity ofthe solvent. Predict whether it will be faster or slower in a more polar solvent. Q.21 There is an overall 29-fold difference in reactivity of 1 -chlorohexane, 2-chlorohexane towards potassium iodide in acetone. (a) Which one is the most reactive? Why? (b) Two of the isomers differ by only a factor of 2 in reactivity. Which two are these? Whcih one is the more reactive? Why? Q.22 The compound KSCN is a source of thiocyanate ion. Write the two most stable Lewis structures for thiocyanate ion and identify the atom in each that bears a formal charge of-1. Q.23 With the help of following data show HBr exhibits the peroxide effect.
AH, 0 H-X x + CH 2 = CH 2 X C H , - C H2 AH 2 X C H 2 - C H 2 + H - X - > XCH 2 CH 3 + x
I HQ HBr HI All are in kJ mole '. -67 -25.1 +46 +12.6 - 50.2 -117.1
Q.24 CHC1,F is found to react more slowly than CHC1, in alkaline hydrolysis with plausible mechanism. Illustrate this phenomenon. vaoA*-**Q.25 Formulate the reactions between but-l-ene in presence of small amount of benzoyl peroxide & (i)CCl4 (ii)CBrCl3 Give your reasons. Q.26 p-Amino benzaldehyde behaves like an amide as is evident by the fact that it is not readily attacked by the nucleophile at the carbonyl carbon. Explain. Q.27 When CH3MgBr react with 5-chloro-2-pentanone, cyclic ether is formed instead of alocohol. Explain. Q.28 The dichlorocarbene reacts with electron rich species like phenol where as it doesn't reacts with benzene explain. tBansal Classes GOC ]l7J
Q.29 Explain the following: (a) 3-pentanol reacts with HBr to give a mixture of 3 & 2- bromopentane. The exact composition of the mixture depends upon whether gaseous or aqueous HBr is used. (b) Hydration of 3-phenyl-1-butene in dil H 2 S0 4 is not a satisfactory method for preparing 3-phenyl-2- butanol Q.30 Why is elimination preferred to hemiacetal formation in the acid catalysed cyclisation ofthis ketone ?
0
Q.31
-OCX
o
D1
'
^ o
( Cyclic ester)
(lactone)
This type ofreaction is called "bromolactonistaion". Suggest a mechanism. Q.32 Draw mechanisms for these reactions, explaining why these particular products are formed.
Q
OH
MeOH
Q.33
C X ^ y <
H2SO4
cone.
> r
Y<f+H20
Q.34 The reaction of cyclopentyl bromide with sodium cyanide to give cyclopentyl cyanide
f y H k / \ r
NC ) , aN ethanol-water
r \ H
Cyclopentyl bromide Cyclopentyl cyanide proceeds faster if a small amount of sodium iodide is added to the reaction mixture. Can you suggest a reasonable mechanism to explain the catalytic function of sodium iodide? Q.35 The reaction of 2,2-dimethyl-1 -propanol with HBr is veiy slow and gives 2-bromo-2-methyl-propane as the major product. CH, CH3CCH2OH CH3 Q.36
CH,
Give a mechanistic explanation for these observations. 1-Bromobicyclo [2.2.11 heptane (the structure ofwhich is shown) is exceedingly unreactive towards nucleophilic substitution by either the SN, 1 or SN,2 mechanism.
[18]
Q. 3 7 We saw that acid-catalyzed dehydration of2,2-dimethyl-cyclohexanol afforded 1,2-dimethylcyclohexene. To explain this product we must write a mechanism for the reaction in which a methyl shift transforms a secondary carbocation to atertiary one. Another product of the dehydration of 2,2-dimethyIcyclohexanol is isopropylidencyclopentane. Write a mechanism to rationalize its formation.
Cte ^ CC3
CH3 2,2-Dimethylcyclohexanol
1,2-Dimethylcyclohexene
Isopropylidenecyclopentane
O^to
Q.3 8 When 2-bromo-2,3-dimethylbutane reacts with a base under E2 conditions, two alkenes (2,3-dimethyl1-butene and2,3-dimethyl-2-butene) are formed. (a) Which of the following bases would give the highest percentage of the 1 -alkene ? (b) Which would give the highest percentage ofthe 2-alkene"
^Q.39 Dr. Don T. Doit wanted to synthesize the anesthetic 2-ethoxy-2-methylpropane. He used ethoxide ion and 2-chloro-2-methylpropane for his synthesis and ended up with very little ether. What was the predominant product of his synthesis ? What reagent should he have used ? Q .40 The following reaction takes place under second-order conditions (strong nucleophile), yet the structure of the product shows rearrangement. Also, the rate of this reaction is several thousand times faster than the rate of substitution of hydroxide ion on 2-chlorobutane under similar conditions. Propose a mechanism to explain the enhanced rate and rearragement observed in this unusual reaction. ("Et" is the abbreviation for ethyl.) Et2N:
H2C-CH-CH2CH3
CI
:NEt2
"H) O
*Q.41 When ethyl bromide is added to potassium t-butoxide, the product is ethyl t-butyl ether. CH3CH2 - Br + (CH3)3C - 0~ +K > (CH3)3C - O - CH2CH3 ethyl bromide potassium t-butoxide ethyl t-butyl ether (a) What happens to the reaction rate if the concentration of ethyl bromide is doubled ? (b) What happens to the rate ifthe concentration ofpotassium t-butoxide id tripled and the concentration of ethyl bromide is doubled ? * (c) What happens to the rate if the temperature is raised ? Q. 42 Give a mechanism to explain the two products formed in the following reaction.
Hx /CH 3 X C = c XCH3 / H % H\
3-methyl-l-butene ^Bansal Classes
Br
NBS,hv
CH3
X
X C-C H/ \h
not rearranged
H\
CH3 +
I ^ C " C H3 BrC-C
H I H rearranged
X
Halogen Derivatives
[19]
Q.4 3 Give the structures of all possible products when 2-chloro-2-methylbutane reacts by the El mechanism. Q .44 Solvolysis of 1,2-dimethylpropyl p-toluenesulfonate in acetic acid (75C) yieldsfivedifferent products: three are alkenes and two are substitution products. Suggest reasonable structures for thesefiveproducts. Q.45 Solution A was prepared by dissolving potassium acetate in methanol Solution B was prepared by adding potassium methoxide to acetic acid. Reaction of methyl iodide either with solution A or with solution B gave the same major product. Why ? What was this product? Q .46 Solvolysis of2-bromo-2-methylbutane in acetic acid containing potassium acetate gave three products. Identify them. Q.47 (a) Write the structures or build molecular models of all the isomeric alkyl bromides having the molecular formula C5HnBr. (b) Which one undergoes E1 elimination at the fastest rate ? (c) Which one is incapable of reacting by the E2 mechanism ? (d) Which one can yield only a single alkene on E2 elimination ? (e) For which isomers does E2 elimination give two alkenes that are not constitutional isomers ? (f) Which one yields the mobt complex mixture of alkenes on E2 elimination ? Q.48 Evidence has been reported in the chemical literature that the reaction (CH3CH2)2CHCH2Br + KNH2 > (CH,CH2)2C - CH2 + NH3 + KBr proceeds by the E2 mechanism. Use curved arrow notation to represent the flow of electrons for this process. Q.49 The given compound give mixture of six products on treatment with CH3OH. Write structures of all five products and give mechanism of the reaction.
Q.50 Comment on the selectivity, (that is, say what else might have happened & why it didn't) shown in this grignard addition reaction used in the manufacture of an antihistamine drug, A.
CI
Q. 51 Outline an efficient synthesis of each of the following compoundsfromthe indicated starting material and any necessary organic or inorganic reagents: (a) Cyclopentyl cyanidefromcyclopentane. (b) Cyclopentyl cyanidefromcyclopentene. (c) Cyclopentyl cyanidefromcyclopentanol. (d) Isobutyl iodidefromisobutyl chloride. (e) Isobutyl iodidefromtert-butyl chloride. (f) Isobutyl azidefromisopropyl alcohol Q. 5 2 Select the combination of alkyl bromide and potassium alkoxide that would be the most effective in the synthesis ofthe following ethers:
^Bansal Classes
Halogen Derivatives
[20]
Q. 5 3 Indicate the major alkene produced by each of the following Br (a) CH 3 -CH 2 -CH 2 -C-CH3 CH3 CH3 (b) CH3-CH2-CH2-C-N(CH3)3OH^-> CH3 CH3
(c) ch
3'k/a >
>
(CH
f
3>3COK >
(d)
Q.54 Choose the compound of molecular formula C7H13Br that gives each alkene shown as the exclusive product of E2 elimination.
(a) ( 3
CH,
(d)
(b)(^CH2
r A
(6)
( c)<>CH3
k/cH3
L ^ C H = CH2
(f)|Q
/CH(CH3)2
(g)J^C(CH3)3 ^ Qx5 5 Select the alkyl halide and a nucleophile that will give each ofthe following products. CH3 - CH2 - CH2 - NH2 t/(fT) CH3 - CH2 - O - CH2- CH3 (c)CH = C-CH 2 -CH 2 -CH 3 Jdf(CH3)2CHS(CH3)2 Je)C6H5-0-CH2-CH3 Q. 5 6 Identify the product in each of the following reactions: (a) C1CH2CH2CHCH2CH3 - i ^ ! l - > C 5 H 1 0 C l I
CI
(b) BrCH,CH2Br + NaSCH2CH2SNa > C4HgS2 (c) C1CH2CH2CH2CH2C1 + Na2S C4H8S Q. 5 7 Write the structure of the principal organic product to be expected from the reaction of 1 -bromopropane with each ofthe following: (a) Sodium iodide in acetone.
O
Sodium acetate ( CH3CONa ) in acetic acid. (c) Sodium ethoxide in ethanol. \Jd) Sodium cyanide in dimethyl sulfoxide. Sodium azide in aqueous ethanol ^(fjSodium hydrogen sulfide in ethanol w (g) Sodium methanethiolate (NaSCH3) in ethanol. ^Bansal Classes GOC
v (b)
12U
Q.5 8 Predict the products of the following SN2 reaction: C 6 H 5 -CH 2 -CH 2 -Br
C H
3
NaLN
>
Jbf
(d) 0 ^ C
CI
H
3
- ( C H
- C H
- C I - ^ >
>
(e)
Na0H
> CH3
Q. 5 9 Draw each of the following reaction in a way that clearly show the stereoisomerism of the products.
me 01
(a)
CH3 - C - Br + CH3ONa
C H
2
>
(b)
- C H
(c)
NaSH SN1
Q.60 What will be the products (A, B, C) in the folowing reaction? RCH = CH2 CC14 hv ^ BrCCA hv A
C Give a mechanism for each of the reactions. Q. 61 Complete the following reactions. Give all possible products in each case. Give mechanism ofthe reactions.
(a)
C H 3
Moist A g 2 Q )
(b)
^CH2C1 Q.62 Identify (A) to (D) in the given reaction sequence. CH - CH, - CH, Q.63
B /hv
CH 2 -CI
HOWA
>
) (A)
alc
f H > (B)
Peroxide
(C) -
LlF
DMF
> (D)
CH3-CH2-Br
> (A)
CH3-CH2-Br^ (B)
ci2/hv
)+(
)+(
( c ^ c S f
>
( F ) + ( G ) + ( H )
c
/
c h
(i)Br2/ a H
(ii) H
>(Q+(D)
>
( E )
( F )
Na0H/F
^ >G +H
Halogen
Derivatives
[22]
Q.65 (a)
(b)
C6H5-CH
aq.NaOH
-CI
>A
(b)
H3C
/c
= c
3 H
\N
+HI
>B
CH,
(c) l ^ J
+ HBr
Peroxide
>C
(d)
CH2CH3
+ HC1
>D
(ii) What are the products ofthe following reactions ? (a) PhC 5 CH + Br2 =
CH3 Br,
H-tO
(b) w
H?0
>
Na0H
H
(c)
Q.67
(A\
K )
2 v >
v >
"2
CI A (b)
-B
Q.68
CH3CH2CH2C1
(i)CH3-C-CH3 (ii)aq.NH4Cl
O II
) p
H2SQ4/A
Q. 70
'
<
MeOCHjCl BuLi
CHBft BuOK
->9
N^CO.E.
Ph - CH = CH
ABansal Classes
GOC
[23]
EXERCISE-IV (A)
^pd Reaction of R-CO-NH2 with a mixture of Br2 and KOH gives R-NH2 as the main product. The [JEE 1992] intemediates involved in this reaction are: (A) R-CO-NHBr (B)RNHBr (C) R-N=C=0 (D) R.CO.NBr2 Which one of the following has the smallest heat of hydrogenation per mole? (B) trans-2-Butene (A) 1-Butene (D) 1,3-Butadiene (C) cis-2-Butene In the following compounds:
OH OH
NO,
(I)
(HI) (C) II > I > III > IV (D) IV > III > I > II [JEE 1998]
The order of acidity is: (A) III > IV > I > II (B) I > IV > III > II
v^4
(A) CHXHBrCH
Q.5
(B)CH H CHBr O O OH (D) CH CH CHBr -TV. ^~Br (C) CHXHBrCH. o A solution of (+) 1 -chloro-1 -phenylethane in toluene racemizes slowly in the presence of small amount
3 2
of SbCl5 due to formation of: (A) carbanion (B) carbene An aromatic molecule will: (A) have 4n n electrons (C) be planar
[JEE 1999] (C) free radical (D) carbocation [JEE 1999] (B) have (4n+2) n electrons (D) be cyclic [JEE 1999] OD
Q.7
The enol form of acetone, after Prolonged treatment with D 2 0, gives: OD (A) CH 3 -C = CH2 O (B) C H 3 - C - C H 3 OH
Amongst the following, the most basic compound is: [JEE 2000] (A) C6H5NH2 (B) p-N02-C6H4NH2 (C) m-N02-C6H4NH2(D) C6H5CH2NH2
Q.9
An SN2 reaction at an assymetrical carbon of a compound always gives: [JEE 2001] (A) enantiomer of the substrate (B) a product with opposite optical rotation (C) a mixture of diastereomeres (D) a single stero isomers
^Bansal Classes
Halogen Derivatives
[24]
Q^M) The correct order of basicities of the following compounds is: CH,C (CH3)2NH (2) (B) 1 > 3 > 2 > 4 (3) (C) 3 > 1 > 2 > 4 CH3CNH (4) (D)L
[JEE 2001]
Identify the correct order of reactivity in electrophilic substitution reaction of the following compounds:
(1) (A)1>2>3>4
(2) (B)4>3>2>1
(3)
(4) (C)2>1>3>4
(D) 2>3>1>4 [JEE 2002] [JEE 2 0 0 3 1 (D) HOC-CH=CH 2 [JEE 2003] (D)CH3C1
^12
Left to right sp2, sp2, sp, sp hybridization is present in: (A) H2C = CH-C=N (B) H2C=C=CH-CH3 (C) H O C - O C H Maximum dipole moment will be of: (A) CCL (B)CHC13 COOH (C)CH2C12
Q.14
when X is made to react with 2 eq. of NaNH2 the product formed will be:
[JEE 2003]
(A)
(C)
fa Bansa!
Classes
GOC
[25]
Q.15
Order ofrate of reaction of following compound with phenyl magnesium bromide is: Ph-C-Ph (I) (A) I > II > III
[JEE 2004]
I! O
II o
II o
Hs
Q.16
YVV53
COOH
X
[JEE 2004]
Correct order of acidic strength is: (A) x > y > z (B) z > y > x Q.17
1 -Bromo-3-chloro cyclobutene on reaction with 2-equivalent of sodium in ether gives [JEE 2005] (A) j
Cf
J
<B
CH 3 COONa(excess) (absolution)
.CI
(C)
(D)
[JEE 2005]
JSO3H O ,H
f o l Q.18 \
SO2COOCH3 (A)
Me
S0 3 Na COONa
(B)
(C)(0)
Me
+CH3COOH
(D)lOJ
Me
+H 2 S0 3
Q.19 Conversion of cyclohexanol into cyclohexene is most effective in (A) concentrated H3P04 (B) concentrated HCl (C) concentrated HCl / ZnCl2 (D) concentrated HBr CH, Q.20 Ph - MgBr + CH3 - C - OH CH, CH,
[JEE 2005]
[JEE 2005]
OH
CH,
(A)
(B)CH3-C-OPh CH,
^Bansal Classes
Q.21
For 1 -methoxy-1,3-butadiene, which of the following resonating structure is the least stable? (A) H 7 C- CH- CH = CH - O - CH, (C) H2C = C H - C H - C H - 0 - C H 3 (B) H 2 C- CH = CH - CH = O - CH3 (D) H2C = CH - CH- CH = O - CH3 [JEE 2005]
CH3 H CH3
Q.22
MCO-^5^H
^5}"N02
CI CH3
[JEE 2005]
CH3
(K) M e O ^ O ^ H
(L)MeO-<g>
OH H
- ^ Q } -NO,
CH3
CH3 H
(M) MeO-^O)H
-(O)-^02
CH 3 OH
(B)only
(C)Monly
(D) K & M
When benzene sulfonic acid and p-nitrophenol are treated with NaHC03, the gases released respectively are [JEE 2006] (A) S0 2 , N0 2 (B) S0 2 , NO (C) S0 2 , C0 2 (D) CO2, CO2 CH3NH2 + CHC13 + KOH - Nitrogen containing compound + KC1 + H20. Nitrogen containing compound is [JEE 2006] (A) CH3-C s N (B) CH3-NH-CH3 (C) CH3 - N = C (D) CH3 N = C
^25
(I) 1,2-dihydroxy benzene (II) 1,3-dihydroxy benzene [JEE 2006] (HI) 1,4-dihydroxy benzene (IV) Hydroxy benzene The increasing order of boiling points ofabove mentioned alcohols is (A) I <II<III<IV (B) I <II<IV<III (C) IV<I<II<III (D) IV<II<I<III
fa Bansa! Classes
GOC
[27]
(i) H2N^Q-CI
(vi)
OM
(ii)
(iii)
< N H Q - C I
(v) (iv)
In this reaction, RCONHBr is formedfromwhich this reaction has derived its name. Electron donating group at phenyl activates the reaction. Hofinann degradation reaction is an intramolecular reaction. How can the conversion of(i) to (ii) be brought about? (A)KBr (B)KBr + CH3ONa (C) KBr + KOH ^27 Q.28 [JEE 2006] (D) Br2 + KOH
Which is the rate determining step in Hofmann bromamide degradation? [JEE 2006] (A) Formation of (i) (B) Formation of (ii) (C) Formation of (iii) (D) Formation of (iv) What are the constituent amines formed when the mixture of (i) and (ii) undergoes Hofinann bromamide degradation?
(i)
(ii)
(A) > = /
D
\-NH2
)=/
D
'\=/
\-NH2
R V - NH, N
(C) (C) i
\-NH 2 $
^Bansal
Classes
Halogen Derivatives
[28]
EXERCISE-IV (B)
Q. 1 Q.2 Q.3 Q. 4 CH3CH2CHC12 "1-KOH
>
?
a1c1
C 6 H 6 + (CH3)2CHCH2C1 ( O V C O O ^ O )
\ _ y X /
monomtration
_H
NaOH SM2
>
Q. 5
Complete the following, giving the structures of the principal organic products: + KNH 9 \\ / I + CHBr 3 +1 - BuOK >B >C
[JEE 1997]
(a)
(b) (c) Q. 6
Write the intermediate steps for each of the following reaction. C 6 H 5 CH(OH) C=CH
H,0
[JEE 1998]
> C 6 H 5 CH = CH-CHO
o c r ^ o a ,
Each of the following reaction gives two products. Write the structure of the products. C6H5CH2CHC1C6H5 CH 3 CONHC 6 H 5
Br AlcK0H A
[JEE 1998]
'
>
2.Fe
Out of anhydrous A1C13 and hydrous A1C13 which is more soluble in diethyl ether? Explain with reason. [JEE 2003] Match K a values with suitable acid: K (ii) Cm) (iv) (v) 3.3 x 10"5 4.2 x 10"5 6.3 xlO"5 6.4 x 10"5 30.6 x 10~5 [JEE 2003] Acid <0)-COOH Me-^^-COOH C ^ C O O H MeO^COOH
COOH
(a)
(b) (C) (d)
(e)
GOC
fa Bansa! Classes
[29]
Q.10
[JEE 2003]
Q.ll
[JEE 2004]
.o.
[JEE 2005] [JEE 2005]
Br CH, c2H5OH(aq.)
Predict whether the following molecules are iso structural or not. Justify your answer. (i)NMe3 (ii)N(SiMe3)3 Give reasons:
H,C
(0
^ acidic solution
(ii) B
_ / " \ _ y \ = /
C2H5OH(aq.)
) neutral
r CH,
(b)
(i)0,
^V
CH,
Na H(aq)
>F (liberated)
(ii)
NaOH(aq.) . p i s n o t liberated
H,C H2N02
(c)
(i)
(ii) I
(d)
faBansal Classes
Halogen Derivatives
[30]
Q.10
[JEE 2003]
Q.ll
[JEE 2004]
OJ
Q.12 Q.13
I> C
[JEE 2005] [JEE 2005]
Predict whether the following molecules are iso structural or not. Justify your answer. (i)NMe3 (ii)N(SiMe3)3 Give
H3C
reasons:
Br CH3 CH
(a)
C2H5OH(aq.)
>
neutral
(b)
(Oo.N^V
CH,
Na H(aq)
> F (liberated)
(ii)
NaOH(aq.)
H,C CH 2 N0 2
p is not liberated
.0
Conc.HNO, Conc.H-.SO4 2JU > N02 + | NO,
(c)
(i)
NO,
(ii) I
(d)
faBansal Classes
Halogen Derivatives
[30]
Q.14
NaBr+Mn 2
FindA,B,C and D. Also write equations Ato Band Ato C. Q!5 (a) (b)
H a . - I w [JEE 2005] where is the dipole moment of stable conformer and x{ is the fraction of that conformer. Write stable conformer for Z - CH 2 - CH 2 - Z in Newman's projection. If psolutjon = 1.0 D and mole fraction of anti form = 0.82, find Write most stable meso conformer of CHD Y I CHDY If (i) Y=CH 3 about C 2 - C 3 rotation and (ii) Y=OH about Cl - C 2 rotation.
faBansal Classes
Halogen Derivatives
[31]
ANSWER KEY Q.l Q.8 Q.15 Q.22 Q.29 Q.36 Q.43 Q.50 Q.l Q.5 Q.9 Q.13 Q.17 Q.21 Q.25 Q.29 D D C A A A A D C B,C,D C,D A,C,D B,D A,B,C C A,D Q.2 Q.9 Q.16 Q.23 Q.30 Q.37 Q.44 Q.51 C A A C C A A D Q.3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 Q.52 Q.2 Q.6 Q.10 Q.14 Q.18 Q.22 Q.26 Q.30 B B B C B C A C EXERCISE-I Q.4 B Q.ll A ' Q.18 B Q.25 D Q.32 B Q.39 B Q.46 C Q.53 C Q.5 Q.12 Q.19 Q.26 Q.33 Q.40 Q.47 B C C A C D C Q.6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 A C A D B B C Q.7 Q.14 Q.21 Q.28 Q.35 Q.42 Q.49 A C D C B A A
EXERCISE-II A,D Q.3 A,B,D Q.7 A,B Q.ll C,D Q.15 D Q.19 B,C Q.23 A,C,D Q.27 B Q.31 EXERCISE-III
Q.l
3 >2> 1 >4
Q.2
IV>I>II>III
Q.3
C-C-C-C-C 1 > C - C - C - C l > C - C - C - C l > C - C - C l c c c (i) (a) II, (b) I, (c) II ; (ii) (a) II, (b) II, (c) I (a) I, (b) II, (c) I, (d) I Q.10 (a) II, (b) I, (c) II, (d) II Q .15 a,c,e,f,g,h Q.45 MeCOOMe
Q.14 b,d,e,g,h
Q 2.1 I
Q.46
C - C - C - C , C-C = C-C, C - C - C - C C c C c c
(f)
C-C-C-C-C
Halogen Derivatives [32]
faBansal Classes
Q.50
C Q.53
( a ) C - C - C = C - C ; ( b ) c - C - C - C = C 5 (<0 C = C - C - C ; (d) C - C - C - C = C C
Br CH,Br ; (b) ; (c) B r - - ( ^ ) - C H 3
;
Q.54
(a)
(d) L y ^ ; ( e ) Q > - C H 2 - C H 2 - B r
(f)
B r ^ '
^[^-CMes
Q.55
(a) CH 3 CH 2 CH 2 C1 + N H 3 ; (b) CH 3 CH 2 ONa + CH 3 CH 2 C1; (c) HCCNa e + CH 3 CH 2 CH 2 -C1 (d) Me 2 CH-Cl + Me 2 S ; (e) C 6 H 5 ONa + CH 3 CH 2 -C1
Q.56
; (c)
Q.57
(a)
; (b)
; (<
; (d) / ^ C N ; (e)
; (f) ^ / S H ; (g)
Q.58
(a) C 6 H 5 -CH 2 -CH 3 -CN, (b) <^>-SCH 3 , (c) CH 3 -<CH 2 ) 9 -I, (d) <ON-ch 3 I 0 , (e) H Me (b) Me (c) +
Q.59
a)CH30-C-CH3; CH 2 CH 3
Et-C-OMe + MeO-C-Et,
Pr Pr
SH
(B)RCHBrCH 2 CCl 3
(C) RCHC1CH2CC13
(a) CHI 3 +(CH 2 ) 4 (COOH) 2 , (b) CHBr 3 +Q-COOH, (c) CHCl 3 +[>-COOH, (d) CHF 3 + EtCOONa (a)CHCl 3 , (b)PhCHO
faBansal Classes
Halogen Derivatives
[33]
Q.66
(d) \
^
Et
Et-CH-CH2-Cl, OH
(df)
Q.67
Q.68
Me 2 C=CH-CH=CH 2
Q.69
A::CC1 2
B:
CI
CI
Q.70
(i)
& Ql>-
0 M e
; (ii) r h
A , COOEt (A) Q.4 Q.9 Q.14 Q.19 Q.24 B D C A D Q.5 Q.10 Q.15 Q.20 Q.25 D B B A C
EXERCISE-IV
Q.l
A, C B, C, D C D C D
D D A C A D
D D D C D B (B)
EXERCISE-IV
C(CH3)3
Q.l
CH 3 CH 2 CHO CH,
Q.2
[ Q
Q.3
^COO-Q^
Br o
Q.4
C6H5-C-CH3 CH,
Q.5
, v J (C)
Ph-C-CHCH,
I / I
faBansal Classes
Halogen Derivatives
[34]
Q.6
C6H5-CH-CeeCH OH
> C 6 H 5 - C H - C = C H 5 ^ - > C 6 H 5 - C H - C = CH OH
C 6 H 5 - CH = C = CH
+
H2
> C6H5 - C H = C = C H
OH 2
C 6 H 5 - CH = C = CH I OH 2
tautomerism "
, C 6 H 5 ~CH=CH-CHO
-FT
o^ch
H NHCOCH 3
" - c r X:H 3
NHCOCH 3
Q.7
(a)
(Major)
(b)[
l^JJ
+r
Br
Q. 8
Anhydrous A1C13 is more stable then hydrous A1C13 because it is having vacant 3p orbital ofA1 which can accept lone pair of electrons from oxygen of diethylether.
Q.9
Q.10
compound. Q.12 Not. NMe 3 is trigonal pyramidal while N(SiMe 3 ) 3 is trigonal planar due to back bonding.
faBansal
Classes
Halogen Derivatives
[35]
CH. 3 Q.13 (a) (i) H5C6 - C - OC2H5 + HBr(acid); (ii) no reaction due to partial double bond character
l CH, 3
(c) (i) due to presence of lone pair of nitrogen atom NO group is electron denating and ortho, para (ii) N0 2 group is electron withdrawing and meta directing (d) Due to reduction of centralring,three four membered antiaromatic rings become stable while on recuction of terminal ring only one antiaromatic ring can be stabilized.
CH3 O2N> -NO2
directing
-OH H
faBansal Classes
GOC
[36]
[[organic c h e m i s t r y !
XII (ALL)
HALOGEN DERIVATIVES
EXERCISE-I (A) EXERCISE 1(B) EXERCISE-II EXRECISE-III EXRECISE-IV(A) EXERCISE IV(B) ANSWER KEY
CONTENTS
EXERCISE-I (A)
(Choose the correct option. Only one is correct) Qlf Which one is liquid at room temperature: ^ (A)CH3C1 (B)C2H5C1 (C)CH3Br ^L (D)C2H5Br
The correct order ofmelting and boiling points ofthe primary (1 ), secondary (2) and tertiary (3) alkyl halidesis: (A)P>S>T (B)T> S>P (C) S > T > P (D)T>P>S Pick up the correct statement about alkyl halides: (A) They show H-bonding (B) They are soluble in water (C) They are soluble in organic solvent (D) They do not contain any polar bond What would be the product when neopentyl chloride reacts with sodium ethoxide: (A) 2-Methyl-2-butanol (B) Neo pentyl alcohol (C) Both 1st & 2nd (D) 2-Methyl-2-butene Reduction of alkyl halide by LiAlH4 is the type of reaction: (A) Nueleophilic substitution reaction (B) Electrophilic substitution reaction (C)Electrophilic Addition reaction (D) None of these 2-methyl butanoic acid is formed by the reaction CHC13, NaOH and (A) Propene (B)Ethene (C)l-Butene (D)2-Butene
Q?f
Q.4
Q. 6 Q.7
CC14 + KOH (excess) end product of the reaction is: (A) K2C03 (B)C0 2 (C) C (OH)4 (D)HCOOK Q. 8 The yield of alkyl bromide obtained as a result of heating the dry silver salt of carboxyic acid with bromine if CC14 is: (A) 1> 3 >2 bromides (B) 1> 2 >3 bromides (C) 3 > 2 > 1 bromides (D) 3 > 1> 2 bromides Which of the following statements is invalid: (A) The more stable the carbocation the faster it is formed (B) Propyl cation changes to more stable isopropyl carbocation by 1,2 shift of a hydrogen (C) Isopropyl chloride reacts with sodium ethoxide to form 1-ethoxypropane (D) Propyl halides reacts with sodium ethoxide to form 1-ethoxypropane Q.10 Nitrochloroform is prepared by the action of chloroform and: (A) Hot aqueous solution ofKN03 (B) Hot aqueous solution ofNaN02 (C) Hot concentrated nitric acid (D) Hot dilute HC1 + aq. NaN02 solution , Odl Which of the following compounds is most rapidly hydrolysed by S^l mechanism. (A)C6H5CI (B) C\-CU2-CU=CU2 (C)(C6H5)3CC1 (D)C6n5CU2C\
o
Q.12 CH3MgBr + CH2 = CH - C - H OH (A) CH2 = C H - C - H CH3 (C) CH3-CH2-CH2-CHO faBansal Classes
H
Q.31
n-CjgH^Br + HC =CNa
>A
n BuLi
> B
H /Imc ar scat
5-methyl-1 -hexene + HBr (peroxides) -> C - ^ D Q.32 (i) (ii) (iii) (iv)
p6roxybenzoicacid
>F
Complete the following by providing (A), (B),(C) and (D): CHjCH^CHjOH CH3CH2CH2I
PBr
3 > (A)
Alc K0H
> (B)
HBf
NH
h+/h
socl
LiAlH4
Alc K 0 H HBr
CHgCH^MgBr
CH CHQ/H
AlcKOn
CH Br
(c)(^J
C1
(d) ^ J j
O I! (e) Ph - CH2 - C - CI
Ph - CH^ - CI O
(QPh-CHj-Cl
> Ph - CH2 - C - CI
(!Bansal Classes
Halogen Derivatives
[19]
EXERCISE-III
Q.l A primary alkyl halide (X) C4H4Br reacted with alcoholic KOH to give (Y). (Y) reacts with HBr to give (Z) an isomer of (X). On reacting with alkali metal such as sodium/dry ether gives (S) CgHj8 which was differentfromthe compound produced when n-butylbromide was treated with Na. What (X), (Y), (Z) and (S). On electrolysis an aqueous ethanoilc solution of so dium chloride gives sweet smelling liquid (X). (X) gives isocyanide test and condenses with acetone tofromhypnotic (Y). What are (X) and (Y)? The alkyl halide C4H9Br (A) reacts with alcoholic KOH and gives an alkene (B), which reacts with bromide to give dibromide (C). (C) is transformed with KOH & sodamide to gas (D) which forms a precipitate when passed through an ammonical silver nitrate solution. Give the structure formulae of the compounds (A), (B), (C) and (D) and explain reactions involved. An unsaturated hydrocarbon (A) C6H10 readily gives (B) on treatment with NaNH2 in liquid NH3. When (B) is allowed to react with 1 -chloropropane, a compound (C) is obtained. On partial hydrogenation in the presence of Lindlar catalyst, (C) gives (D), C9H18. On ozonolysis (D) gives 2,2-dimethylpropanal and 1 -butanal. Give structures of (A), (B), (C) and (D) with proper reasoning. One mole of each bromoderivative (A) and NH3 react to give one mole of an organic compound (B). (B) reacts with CH3I to give (C). Both (B) and (C) react with HN02 to give compounds (D) and (E), respectively. (D) on oxidation and subsequent decarboxylation gives 2 -methoxy-2-methylpropane. Give structures of (A) to (E) with proper reasoning. A chloro derivative (A) on treatment with zinc-copper couple gives a hydrcarbon withfivecarbon atoms. When 'A' is dissolved in either and treated with sodium, 2,2,5,5-tetramethylhexane is obtained. What is the original compound A? A primary alkyl halide (A) C4HjBr reacted with alcoholic KOH to give (B). (B) reacts with HBr to give (C) an isomers of (A). (A) on reacting with sodium gives (D) CgHlg which was differentfromthe compound produced when n-butylbromide was treated with Na. What are (A), (B), (C) and (D). One mole of a hydro carbon (A) reacts with 1 mole of bromine giving a dibromo compound C5HJ0Br2. (A) on treatment with cold dilute alkaline KMn04 solution forms a compound C5H1202. on ozonolysis (A) gives edquimolar quantities of propanone and ethanal. Deduce structure of (A). A hydrocarbon (A) was found to contain 85.7% carbon and 14.3% H. This compound consumes 1 molar equivalent of hydrogen to give a saturated hydrocarbon. 1 g of (A) just decolourised 3 8.05 of 5 % solution by weight of Br2 in CC14. Compound (A) on oxidation with conc. KMn04 gave a compound (C), C4HgO and (B) acetic acid. Compound (C) can easily be prepared by the action of acidic aqueous mercuric sulphate on 2-butyne. Deduce (A), (B) and (C).
Q.2 Q.3
Q.4
Q. 5
Q.6
Q.7
Q. 8
Q.9
Q. 10 When a hydrocarbon (A) is treated with excess of hydrogen chloride, a dihalogen derivative (B) is obtained. The compound (B) is treated separately with aqueous and alcoholic KOH to give compounds (C) and (A) respectively both having three carbon atoms. Compound (C) does not reduce Tollen's reagent and compound (A) give white precipitate with ammonical silver nitrate. Assign structures to compounds (A) to (C).
^Bansal Classes
Halogen Derivatives
[20]
Q.ll
An organic compound (A) C7H)5C1 on treatment with alcoholic caustic potash gives a hydrocarbon (B) C7H14. (B) on treatment with ozone and subsequent hydrolysis gives acetone and butyraldehyde. What are (A) and (B). Explain reactions.
Q.12 A dihalogen derivative (A) of a hydrocarbon having two carbon atoms react with alcoholic potash and forms another hydrocarbon which gives a red precipitate with ammonical cuprous chloride. Compound (A) gives an aldehyde when treated with KOH (aq). What is (A)? Q.13 A white precipitate was formed slowly when AgN03 was added to a compound (A) with molecular formula C6H13C1. Compound (A) on treatment with hot alcoholic KOH gave a mixture of two isomeric alkenes (B) and (C) having formula C6H,2. The mixture of (B) and (C) on ozonolysis furnished four compounds (i) CH3CHO, (ii) C2H5CH0, (iii) CH3COCH3, (iv) (CH3)2CH. CHO What are (A), (B) and(C). Q.14 0.369 g of a bromo derivative of a hydrocarbon (A) when vaporized occupied 67.2 mL at NTP. (A) on reaction with aqueous NaOH gives (B). (B) when passed over alumina at 250 C gives a neutral compound (C) while at 3 50C it gives a hydrocarbon (D). (D) when heated with HBr gives an isomer of (A). When (D) is treated with dil. F^SO^j, (E) is obtained. Identify (A) to (E) and explain the reactions. Q.15 An organic compound (X) on analysis gives 24.24 % C, 4.04% H. Further sodium extract of 1.0 g of (X) gives 2.90 g ofAgCl with acidified AgN03 solution. The compound (X) may be represent by two isomeric structures (Y) and (Z). (Y) on treatment with aqueous KOH solution gives a dihydroxy compound, while (Z) on similar treatment gives ethanal. Find out (X), (Y) and (Z). Q.16 0) (ii) (Hi) (iv) A chloro compound (A) showed the following properties: Decolourized bromine in CC14 Absorbed hydrogen catalytically. Gave a precipitate with ammonical cuprous chloride When vaporised 1.49 g of (A) gave 448 mL ofvapours at STP. Identify (A) and write down the equations of reactions.
(I%Bansal Classes
Halogen Derivatives
[21]
EXERCISE-IV (A)
Q.l Chlorination oftoluene in the presence of light and heat followed by treatment with aqueous NaOH gives (A)o-cresol (B)p-cresol (C) 2,4-dihydroxytoluene (D) Benzoic acid [IIT 1990] Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl halides due to (A) The formation ofless stable carbonium ion (B) Resonance stabilization (C) The inductive effect (D) sp2 hybridised carbon attached to the halogen [IIT 1990] 1-Chlorobutane on reaction with alcoholic potash gives: (A) 1-butene (B) 1-butanol (C)2-butene (D)2-butanol [ITT 1991] The products of reaction of alcoholic AgN02 with ethyl bromide are (A) Ethane (B) Ethyl nitrite (C) Nitroethane Q.5 [ITT 1991] (D) Ethyl alcohol
, Qrf ^
When nitrobenzene is treated with Br2 in presence ofFeBr3 the major product formed is: m-bromonitrobenzene. Statements which are related obtain the m-isomer are (A) The electron density on meta carbon is more than on ortho and para position (B) The intermediate carbonium ion formed after initial attack of Br+ at the meta position is least destabilized. (C) Loss of aromaticity when Br+ attacks at the ortho and para position and not at meta position (D) Easier loss of H+ to regain aromaticityfromthe meta position thanfromotho and para positions. [ITT 1992] Arrange the following compounds in order ofincreasing dipole moment Toluene m-dichlorobenzene o-dichlorobenzene p-dichlorobenzene I II III IV (A) I < IV < II < III (B) IV<I<II<III (C) IV<I<III<II (D) IV<II<I<III [IIT 1996] In the reaction of p-chloro toluene with KNHj in liq. NH3, the major product is: (A) o-toluidine (B) m-toluidine (C) p-toluidine (D)p-chloraniline [IIT 1997] (CH3)3CMgCl reaction with D 2 0 produces: (A) (CH3)3CD (B)(CH3)3OD (C)(CD3)3CD (D) (CH3)3OD [IIT 1997] Benzyl chloride (CgHjCH^C^canbe preparedfromtoluene by cMorinationwith: (A) S02CI, (B) SOClj (C)C12 (D)NaOCl [IIT 1998]
Toluene, when treated with Br2/ Fe, gives p-bromotoluene as the major product, because the CH3 group [IIT 1999] (A) is para directing (B) is meta directing (C) activates the ring by hyperconjugation (D) deactivates the ring The order ofreactivity ofthe following alkyl halides for a S ^ reaction is: (A) RF > RC > R-Br > R-I (B) R-F > R-Br > R-Cl > R-I (C) R-Cl > R-Br > RF > RI (D) R-I > RBr > R-Cl > R-F [ITT 2000]
0Cfl
^Bansal
Classes
Halogen Derivatives
[22]
Identify the set of reagents / reaction conditions 'X' and 'Y in the following set of transformation: CH3 - CH2 - CH2Br x
>
Product
(A) X = dilute aqueous NaOH, 20C; Y=HBr / acetic acid, 20C (B) X = concentrated alcoholic NaOH, 80C; Y=HBr/ acetic acid 20C (C) X = dilute aqueous NaOH, 20C; Y=Br 2 / CHC13,0C (D) X = concentrated alcoholic NaOH, 80C; Y=Br2/CHC13,0C Q.13 CH3MgBr + Ethyl ester - which can be formed as product, (excess)
CH2CH3 CH,
(A) HO-
-CH 2 CH 3
(B) HO-
" CH2CH2CH3
CH2CH3 CH3
CH 3 ' CH,
Match the following: Column I (A) CH3-CHBr-CD3 on treatment with ale. KOH gives CH2:=CH-CD3 as a major product. (B) Ph - CHBr - CH3 reacts faster than Ph-CHBr-CD3. (C) Ph-CHj-CHjBr on treatment with C2H50D/C2H50~ gives Ph-CD=CH2 as the major product. (D) PhCH^f^Br and PhCD2CH2Br react with same rate.
/
Column II (P) El reaction (Q)E2 reaction (R) El cb reaction (S) First order reaction
EXERCISE-IV
Q.l
(B)
[IIT 1992] [IIT 1992] [IIT 1993]
(a) jvf
Q.2
Amongst three isomers of nitrophenol, the one that is least soluble in wateris_ Identify the major product in the following reactions: CI CgHj CH2 CH - CH3
KOH A
->
(ii) Q.3
C6H5COOH + CH 3 MgI-
>9+ ?
An alkyl halide X of formula CfiH]3Cl on treatment with potassium tertiary butoxide gives two isomeric alkenes Y and Z (C6H12). Both alkenes on hydrogenation give 2,3-dimethylbutane. Predict the structures ofX, YandZ. [IIT 1996]
faBansal Classes
Halogen Derivatives
[23]
Q. 4
Predict the structure of the intermediates/products in the following reaction sequence - [ET 1996]
Br HMeOPh
Q.5 (b) Q. 6
_AicohaiicKOH^
Heat
H1(excess)
(CH3)2CHOCH3
Heat
Q.7
c H OH
2 5
A
"
Q. 8
How would you synthesis 4 methoxyphenol from bromobenzene in NOT more thanfivesteps? State clearly the reagents used in each step and show the structures of the intermediate compounds in your synthetic scheme. [IIT 2001] An alkene A (C16H16) on ozonolysis give only one product B (C8HgO). Compound B onreaction with NaOH/I2 yields sodium benzoate. Compound B reacts with KOH/NT^NF^ yielding a hydrocarbon C (CgHj Q). Write the structure of compound B and C. Based on this information two isomeric structures can be prepared for alkene A. Write their structures and identify the isomer which on catalytic hydrogenation (t^/Pd-C) gives a racemic mixture. [IIT 2001] Give maj or products A, B, C and D in following reaction sequence.
CH2-C1
K C N
Q.9
Q.10
[IIT 2004]
> / a\
( A )
(i)NaOEt/EtOH (ii)PhCHO/A
.
>
r m ( B )
H3Oe '
. ^
DMF
^Bansal
Classes
Halogen Derivatives
[24]
ANSWER KEY
EXERCISE-I
Q.l Q.8 Q.15 Q.22 Q.29 Q. 36 Q.43 Q.50 D B C C B A A B Q.2 Q9 Q.16 Q.23 Q.30 Q.37 Q.44 A C B D C C B Q.3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 C C A C B C A Q.4 Q.ll Q.18 Q.25 Q.32 Q.39 Q.46 D C D D B A D
(A)
Q.5 Q.12 Q.19 Q.26 Q.33 Q.40 Q.47 A C C B C B B Q6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 D A D B C A A Q7 Q.14 Q.21 Q.28 Q.35 Q.42 Q 49 A D B A A A C
EXERCISE-I
Q.l Q5 Q9 Q.13 Q.17 Q.21 Q.25 Q.27 Q.29 D Q.2 A,C Q.6 A,C,D A,B,C, P B,C,D Q.10 B,D A,C,D Q.14 A,C,D A,B Q.18 A,B,C A,C Q.22 B,C A 3, B 2 ,C 1,D 2 > A>2, B>!, C>4, D - 3 ( A ) - Q ; ( B ) - S ; ( C ) - R; (D) - P Q.3 Q.7 Q.ll Q.15 Q.19 Q.23 Q.26 Q.28 Q.30
(B)
B,C Q.4 A,B B Q.8 A,B,D A,D Q.12 A,C,D B,D Q.16 A,B,C,D A,B Q.20 A,B,C A,B,C,D Q.24 B,C,D A -> 4, B 3,4, C - > 3, D -> 1,2 ( A ) - S ; ( B ) - -Q; ( C ) - R ; ( D ) - P (A)-Q;(B)-- R ; ( C ) - P ; ( D ) - Q
EXERCISE-II
Q.l
(i) CH 3 - CH - CH,, OH
Q.4
(ii)
Q-5
(A)\TSJ H
Me Me Me I I I (c) (A) Me - C = CH - Me, (B) Me-C-CH 2 -Me, (C) Me-C-CH 2 Me OEt (d)(A) n
Me
1 1 OTs
, (B) | 0 | ,(c) | O j
Me H
Me
Br
faBansal Classes
Halogen Derivatives
[25]
Q.6
Et
OH
OH (c) Et-CH-Et
| ^CH2-CH2-OH
(b) Ph-C-<^>
o
(e)
Q.7
(d)
Q.8
H
Bs C - C - C = C-C1
Q.9
A=
O L - C H - C H = CH9
I
C
CH3 Conversion Q.10 (a) & (c) CH3 Q.ll (a)AsEt-I (b) B = CH3 - CH - OH (l)NaNH2 (2) H^/Pd BaS04
(c) Me2C=CH2 OH
(d) Me2C=CH2
Q.12 The mechanism of C1CH2CH2CH2CN (ii) PhCHF2 (iii) FCH2CH = CHC02Me (iv) Efl (v) no reaction Q.13 (i) Chloroform responds carbylamine test while ethyl alcohol does not. Carbylamine test- The compound is heated with aniline and alcoholic caustic potash-an obnoxious smell of phenyl isocyanide (C6H5NC) is produced. (ii) Chlorine atoms of chloroform can be easily replaced by - OH group s on treatment with NaOH. Hence chlorine atoms come in the form of sodium chloride. The solution thus when treated with silver nitrate solution gives white precipitate of silver chloride. Chlorine atom in vinyl chloride is not readily replaced by NaOH, hence it does not give precipiatet with AgN03 solution. (iii) The two compounds are hydrolysed with aqueous NaOH when 1,1 -dibromoethane form acetaldehyde while 1,2-dibromoethane gives glycol. (iv) Chlorine atom in chlorobenzene is very less reactive, while chlorine in cyclohexyl chloride is very reactive. Hence the two can be differentiated as above in (ii) (v) Apply test (ii) as above; when benzyl chloride gives white precipitate with AgN03 solution, while O chlorotoluene does not give precipitate. Alternately, the compounds are oxidised when o chlorotoluene give o-chlorobenzoic acid when benzyl chloride gives benzoic acid (having non chlorine.) (vi) n - Hexane does not respond CI" ion test even after fusion with Na and treatment with acidic AgN03. the remaining three compounds are distinguished by their reactivity with alcoholic AgN03 solution. ^Bansal Classes Halogen Derivatives [26]
Q.14 The elimination ofHI (or DI) involves breaking up of C - H (or C-D) elimination is faster in case of CH3 - CH,I. Q.15 H3C-CH-CH-CH3 CH3 CI KQHW > C H 3 - C = C H - C H 3 + C H 3 - C H - C H = CH2 CH3
ch3
shydrogenated carbon.
s with I2 to give PI3 a > + 3I 2 ->2PI 3 t OH + PI3 3RI + H 3 P0 3 Q.21 KCN is an ionic compound [K+(:C =N:)-] in which both C and N carry a 1 to give alkyl cyanide AgCN N atom and R-N = Cis
faBansalClasse
Q.22 The strong -1. E offluorineatom in F3C - C < produces partial +ve charge on C atom of CF3 which ultimately increases+ve charge on 2nd carbon atom to destabilize it
F
t i F
+5
In F3C+, the unshared pair of electrons in the p orbitals of each of thefluorineatom are shifted to C+ via p-p orbital overlapping and thus stablizing F3C+ ion Q.23 Dry gaseous hydro halogen acids are better electrophile. Also in aqueous solution F^O acting as nucleophile may produce alcohol. Q.24 KI reacts with RC1 to form RI. This RI molecule now hydrolysed easily to give ROH because alkyl iodide are more reactive than alkyl chloride. RC1 + KI - RI
H0H
Q.25 The more pronounced the nucleophilic activity ofthe attacking reagent, then the more the SN2mechasnism will be favoured. Since in SN1 mechanism the raegent doesnot enter into the rate determining step of ionisation How ever it can also be expected that as the nucleophilic activtiy is so slow that the mechanism will changefromSN2 to SN1 Q.26 The dielectric constant of water is greater than that of aqueous acetone, and so ionisation of benzyl chloride is facilitated. Q.27 On movingfrom3 to 1 alcohol rate of ^ 2 reaction decreases and reaches to minimum and mechanesm changesfromSN2 to SN1, Then rate of SN1 rate of reaction increases. Q.28 Anhydrous A1C13 is used as a catalyst infriedelcrafts alkylation. Q.29 tert-Butyl chloride, sec butyl chloride and CC14 with ale. silver nitrate Me3C - CI >
c2H^ Br
">CHC1>CC1 4
Q.30
(a)As Q
C ^
j]
D.
Q f
-10
1=
CuLi 2
Hs
o
NOMENCLATURE OFORGANIC COMPOUND
faBansal Classes
[28]
Me
Me
Pr, (B) Pr
H
EtO
Q.31
A = CjqHjj-C^CH
e B e C10H21-C^CLi
C-C-C-C-C-C-Br C E e C1qH21 - C = C - ( C H 2 ) 4 - C H - C H . H H CH
(i)A,CH 3 CH 2 CH 2 Br;B, CH 3 CH = CH 2 ; C, CH 3 CHBrCH 3 ; D, CHgCHNE^CHg A, CH 3 CH = CH^ B, CH 3 CHOHCH 3 ; C, CH3CHC1CH3; D, CH 3 CH 2 CH 2 A, CH 3 CHBrCH = CIi 2 ; B, CH2=CH-CH=CH2; C, CH 3 CHBrCH=CH 2 & CH 3 CH = C H - C ^ B r A, CH 3 Clr^CHOHCH 3 ; B, CH 3 CH 2 CHBrCH 3 ; C, CH 3 CH = CH - CH 3
EXER
CISE-III
Br
Q.L
CH 3 - C = CH 2
Q.2
(Y)
Chloretone (Hypnotic)
Q.3
CH 3 CH 2 CH 2 CH 2 Br
CH 3 CH 2 CH = CH,
(A) CH 3 - CH2- C = CH
(B)
(C)
<P)
<!SBansal Classes
Halogen Derivatives [29]
Q.4
(CH 3 ) 3 C - C 3 CH (A)
(CH 3 ) 3 C - C =C"Na+
(CH3)3C-C = C H ^ ^ C T ^ (C)
(b)
Q.5
CH3-C(CH3)-CH2-CH2-Br (A) OCH 3 CH 3 - C(CH 3 ) - CH 2 CH 2 - NHCH 3 (C) OCH, CH3-CH-CH2-CH2-N-N = O CH, (E)
Q.6
(CH 3 ) 3 C - C ^ C L CH 3
I
CH, C H 3 - C = CH
CH, H 3 C C CH 3 Br
Q.7
(Q
Q.8
^CH,
"H
CH^ CH2
Q.9
CH3X
C = CH - CH,
CH 3 -COOH (B)
CH, (Q
;c = o
(A)
<!SBansal Classes
Halogen
Derivatives
[30]
Q.ll
CH3(CH2)2CH = C(CH3)3
(B)
CH3.
Q.13 (CH3)2CH-CHCH2CH3 (A) (CH3)2CH CH = CH CH3 (B) ^ C =C (C)
.C2H5
Q 14 (A) CHGCE^CTYBR, (B) C H ^ H ^ O H , (C) CHGCH^C^OC^C^C^, (D) CHJ-CH-CH^ (E)CH3CH(OH)CH3 Q. 15 (X) C2H4C12, (Y) CI - CHjCHJ - CI, (Z) CH3CH Q.16 HC^C-CH^Cl EXERCISE-IV Q.l D Q.2 D Q.3 A Q.8 A Q.9 A,C Q.10 A,C Q.14 A - Q; B - Q; C - R,S; D - P,S Q.4 Q.ll C D (A) Q.5 A,B Q.12 B Q.6 B Q.13 D Q.7 B
(B)
^Bansal Classes
Halogen Derivatives
[31]
ch3 ch3
ch3
ch3
Q.3
ch3 ch3
HQ.4
MeOPh
-Ph
CH 3
Q.5
Q.6
(A)fQ
,CH-CH 2 Br
C=CNa
NaNH,(liq.) CH-J
G=CCH3
*(B)
CH,
Q.7
CH 3 -C-CH 2 CH 3
oc2h5
Br NaOH ONa OMe MejSO^ [ o ] ' conc.H,SOd SO,H OMe NaOH OMe OMe
^ I C 3 J A high pressure [ o )
-Co)ONa OMe
->(0)
OH
Alternative rout
Br Br
naoh
Br
Br
n a o h
OMe
o j - ^ ^ i o j
SOiH
> [ q j ^ l o j - . .
ONa OMe
> [ o j - ^ l q .
ONa OH
Q.9
(A) PhC(Me)=C(Me)Ph
KOH KU
NH3-NH3
CN
COOH
Q.10 (A)
(D)[OJLOj
mBansal Classes
Halogen Derivatives
[32]
Q.13
Which is incorrect about Hunsdicker reaction? (A) Only Cl2 can give alkyl halide (B) I2 will give ester when treated with RCOO Ag (C) The reaction proceeds through free radical (D) F2 cannot give alkyl halide Major product for the reaction
Q.14
->is:
Br
(A)
Br
Br
(C)
Me f5 HO|H Et
11
(D)
Me H|CI Et
1
Br
(A)
Br MgCl
*{S
V
CHOHCH3
(B)
^-Br
MgBr
&
CHOHCHi
MgCl
(C)f|
Br
&
^-CHOHCH3 H,0 +
> C4H10O (alcohol) (B) Alcohol B reacts fastest with Lucas reagent. Hence A and B are
O O
(C) C H 3 - C - 0 - C 2 H 5 , ( C H 3 ) 2 C H 0 H
II
(D) H - C - O - C 3 H 7 , ( C H 3 ) 3 C O H
II
faBansal Classes
NOMENCLATURE
OFORGANIC
COMPOUND
[3]
Q.18 The hydrolysis of alkyl isocyanides (R-CH2-N C) gives (A) RNHCOOH (B) R - CH - COOH (C) RNH2 + HCOOH (D) RCH2NH2 + HCOOH NH2 What is product of the following reaction?
CI CI Mg ET,0
Qc
MgCi
(A)
(B)
CI
MgBr
(Q
\JX*
1 X-Br
H i HO-C
V^
B r
V~V
OH,CH 3
H A _ A H
Ais:
HOV
(B)
H\/
\/
CHCI3 + OH HCOO" Intermediates ofthis reaction are (B) :CCL (C) both (D) None (D)BothA&B Racemic mixture is obtained due to halogenation of: (A)n-pentane (B) Isopentane (C) neopentane
J&
For CH3Br + OH" > CH3OH + Br the rate of reaction is given by the expression: Q.24 (A) rate = k [CH3Br] (B) rate = k[OH"] (C) rate = k [CH3Br][OH_] (D) rate = k[CH3Br] [OH"] Which will give white ppt. with AgN03? Q.25 (A) \ )CI (B) ( O V - C I (C) ( O / ~ c h 2 c i (D) Both A & C
The reaction of SOCl2 on alkanols to form alkyl chlorides gives good yields because (A) Alkyl chlorides are immscible with SOCl2 (B) The other products of the reaction are gaseous and escape out (C) Alcohol and SOCI2 are soluble in water (D) The reaction does not occurs via intermediate formation of an alkyl chloro sulphite
<!Bansal
Classes
Halogen Derivatives
[194]
Q.27 True about alkyl halides is/are: (A) Tertiary alkyl halides undergo ^2 substitutions (B) Alkyl iodides on exposure to sunlight gradually darken (C) Alkyl chlorides do not give beilstein test (D) A nucleophilic substitution is most difficult in alkyl iodides Q.28 The product formed when glycerol reacts with PC15 is(A) 1,2,3-trichloropropane (B) Glycero monochlorohydrin (C) Glycero dichlorohydrin (D) All of these Q.29 On heating glycerol with excess amount to HI, the product formed is(A)Allyl iodide (B) Isopropyl iodide (C) Propylene (D) 1,2,3-tri-iodopropane To prepare 3-ethyl-3-pentanol the reagents needed are:
Q.34
H_
HCH
c H O-
h3Cx
(A)
(B)
>
<
H3Cx
(C) IK
^ch3
^D (D)
H3Cx
D /
^H
X
C = C
\ CH3
<!Bansal Classes
Halogen Derivatives
[5]
Q35
(A)
u O H - A CH 3
(B)
LaJ
(D),
Q.36
BRH
E2
(A)
(B)
(C)
J J
S ) E ^ ^ n e 0 S 8 e n e ^EAylcWoTde (A) CH3CHO and PC15 (C) CHj = CH2 and Q.39 CH3 - C - CH3 - i s > (A)
(D)]
tij
Agp<nvder
(B) CH3COCH3 and PC15 (D) CF^ = CHC1 and HCl > (B)
H s0
il
(A)] (C)] Q.40
^^rtzi rTritr
A ( A ) Q CB)|) ( C ) ^
Q.41
042
.(D) I
Q. 43 The appropriate naming for the second step in the haloform reaction is: (A) Halogenation (B) Dehydrohalogenation (C) Reduction (D) Dehydrogenation Q. 44 Which product is obtained when bleaching powder is distilled with acetone: (A) CC14 (B) CHClg (C) CH2C12 (D) CH3C1 Q.45 What will be the reduction product of following reactions:
+2H Zn/HCl (ale) CHCI3+4H Zn/HCJ (aq.) +6H Zn/H 2 0
(A) C H ^ , CH3CI, CH4 (C) CH3CI, C H ^ , CH4 Q.46 Fe/HCl reduction of 'pyrene'(CCl4) gives: (A) CH4 (B)CH2C12
(B) CH4, CH3CI, C H ^ (D) CH3CI, CH4, CF^Cl (C) CHoCl (D)CHC13
Q. 47 Addition ofbromine on propene in the presence of brine yields a mixture of: (A) CH3CHClCH2Br and CH^CHBrCI^Cl (B) CH^CHClCF^Br and CH3CHBrCH2Br (C) CH3CHC1CH2C1 andCT^CHBrCHjBr(D) C^CHCIC^CI and CH3CHBrCH2Cl 0 Q.48 is converted into /^Y3 I by:
(A) (i) CH3~ Mgl, H30+ (ii) H2S04, A, (lii) HBr, R202 (B) (i) CH3- Mgl, H30+ (ii) H2S04, A, (iii) HBr (C) (i) CH3-MgI, H30+ (ii) HBr (D) (i) HBr, R ^ (ii) CH3-MgI, H30+ Q. 49 To form Malonic acid, by shortest possible route, we have to start a reaction from: (A) Ethyledine chloride (B) Methyl chloride (C) Methylene chloride (D) Chloro ethan Q. 5 0 Frankland reagent is: (A) Dialkyl lithium (B) Dialkyl Zinc (C)Dialkyl magnesium (D) Dialkyl aluminium
<!Bansal
Classes
Halogen Derivatives
[197]
EXERCISE-I (B) (Choose the correct option. One or more than one are correct) Q.l In the given reaction:
H
[X]is:
H Br H
(A)kXJ
Q.2
(B)rN
(C)
Br
(D)
Br
Consider the following statements? (A) CHJ-CHJ-CHJ-I will react more readily than (CH3)2 CHI for SN2 reactions. (B) CH3-CH2-CH2-C1 will react more readily than CT^-Cf^-CHj-Br for SN2 reaction. (C) CH 3 -CH 2 - CH 2 -CH 2 -Br will react more readily than ( C H ^ C - C I ^ - B r for SN2 reactions (D) CH 3 -0-C 6 H 5 -Br will react more readily than N0 2 -C 6 H 5 -CH 2 Br for SN2 reaction A solution of (R)-2-iodobutane, [a] = -15.9 in acetone is treated with radioactive iodied, until 1.0% of iodobutane contain radioactive iodine, the specific rotation of recovered iodobutane is found to be 15.58, which statement is correct about above information. (A) It has optical purity 96% (B) % of R in solution is 99% (C) Racemic mixture is 2% (D) Final solution is dextrorotatory Which are possible products in following
CH 3 CH 2 CI CH 2 OH . A moistAg,U 2 > CH 2 OH
Q.3
Q. 4
CH,
() > CC
() D
CH
OH
In which product formation takes place according to Hoffinann's rule (A) CH 3 CH 2 - CH - CH 3 Br (C)
t B
(B) CH 3 CH 2 - CH - CH 3 Br
CH C
3 ^OK >
CH 3 CH 2 -CH-N CH,
&/
CH 3 CH 3 CH,
oh
>
(D) CH CH C H - C H
S
011
>
S(CH3V
faBansal Classes
NOMENCLATURE
OFORGANIC
COMPOUND
[8]
Q.6
A+B
(i)Et2
> Alcohol
H2Cr 4
> Ketone
H CH
Q.7
I
H
CH3 (A) C H 3 - C H - C H 2 B r
(D) C H 3 - C H - C H3 3
(A) CH3 CH2CH2I will react more readily than (CH3)2CHI for (B) CH3CH2CH2C1 will react more readily than C^CHjCHjBr for (C) CH3CH2CH2CH2Br will react more readily than (CH^CH-CI^Br for (D) CH 3 -0-C 6 H 4 -CH 2 Br will react more readily than N0 2 -C 6 H 4 -CH 2 Br for S. Q. 9 Which of the following will react with AcOAg (A)R-NH2 (B)R-OTs (C)R-N 3
(D)R-Br
^Bansal Classes
Halogen Derivatives
[9]
H-C-OTS
NaCN
CH3CH2CH-CN
which of following statements are correct for above reaction. (A) Product formation takes place due to the breaking of O-Ts (B) The reaction is S n2 (C) The reaction is Sn1 (D) Configuration ofproduct is (R) Q.ll Benzoyl chloride is less reactive than acetyl chloride for nucleophilic acyl substitution reaction because 0 (A) - C - group ofbenzoyl chloride is in conjugation with benzene ring. This makes benzoyl chloride more stable than acylchloride. (B) CH3- group of acetyl chloride make C-Cl bond stronger due to the +1 effect. (C) C6H5- group ofbenzoyl chloride make C-Cl bond weaker due to +R effect. (D) Carbonyl carbon in benzoyl chloride is less electron deficient than acetyl chloride Q.12 Bromination can take place at
(A)L
(B)5
(C)3
(D)4
Q.13 Which of following will give syn-elimination (A) CH3CH2CH2-OCOCH3 (B) CH3CH2CH-CH3 CI
I I s
CH3
<!Bansal
Classes
Halogen Derivatives
[10]
(B) Major product is (C) The reaction is thermal elimination reaction (D) The reaction is cyclic E2 reaction Q .15 Haloform reaction is given by (A) All 2 alcohol (C) All the compounds having CH , - C - group (B) All methyl ketones (D) Chloral
Q .16 Identify the compounds that will undergo NGP reaction (B) CH3-NtICH2CH2CH2Br (A) CHjCHj-S-CHjCHjBr (C) C H 3 - C H - C = O Br (D) CHg-O-CH^CI^CI^Br
le 0
(A)
(B)
CMe3
CMe,
CMe,
(C)
Br
<P)
Q.18 3-Phenyl-3-pentanol can be prepared from grignard reagent & other component which can be (A) 3 -pentanone (B) Ethylbenzoate (C) Ethyl phenyl ketone (D) Propanoyl chloride Q.19 In which of following reaction inverted product will obtained. (A) SN1 (B)Sn2 (QSnNgp (D)V
(B)
(C)
0>
"0
[11]
Halogen Derivatives
Q.21
SN1 & SN2 is not favourable in (A) HJC = CH-C1 (B) Ph-CHJ-Cl
(C) Ph-Cl
(D) H ^ C H - C I V C L
Q.22
SN1 & SN2 product are same in (excluding stereoisomer) (A) (B)
(Q (D) Ph - C H - CH - CH 3
a
NaOI
)
CH 3 CI
Q.23
Rate ofS N 2 depends on (A) Cone of Nucleophile (C) Nature of leaving group
C T yellnw solid
Q.24
G can be (A)CH3-C-OCH3
I I O
(C) CD3COH
Q.25
Match the List I (reaction) withList II (reaction intermediate) and select the correct answer using the codes given below the Lists.
List I Listn
>
alc.KOH/A
CF2 = CC12
(1)
Transition state
(2)
Carbocation
> CH 2 -CH 2
(3)
Carbanion
aq.KOH/A
>
(4)
Free radical
CH,
CH,
^Bansal Classes
Halogen Derivatives
P2J
Q.26
Match the List I with List II and select the correct answer using the codes given below the Lists. List I Listn (A)E1CB (1) Quaternery Amine oxide (B) Saytzeff alkene as major product (2) Xanthate
CI
(C)E2 (D)E C
(3) (4)
CH3-CH2-CH-CH3 C6H5-CH2-CH-CH3
Q.27
Match List I with List II and select the correct answer from the codes given below: ListI List II (A) (B) (C) (D) CH 3 -O-SO 2 CH 3 + C 2 H 5 O CH 3 -CH2-I + PH 3
Q 0
Q.28
Match List-I with List-II for given S n 2 reaction & select the correct answer from the codes given below Z-CHJBR + CH 3 0 List-I (A)H(B) CH 3 (C)C 2 H S CH 3
Z-CH 2 -OCH 3 + Br
List-n (P)0.1
(0)3
iftcdl'i
(R)l
CH
(D)
CH
(S)100
Q.29
Match List-I & List-II and select correct answer List-I (A) R-MgX + HCHO n-carbon (B)R-MgX + (CH2) 2 0 n-carbon (C) R - M g X + C 0 2 n-carbon > Adduct
H,O
Adduct
>
Adduct
H3
>
Adduct
3 >
faBansal Classes
Halogen Derivatives
[13]
Q.30
List-I
/OCH W3
List-n
-C>
CH,CH 2 Q CH3O
>
(A)
CH,0 CH,0
(P)E1
0 II
CH 3 CH 2 O CH,CH,OD
(Q)E2
(C)
(R)Elcb
Br CD)
Br
ale. KOH
(S)Ec
feBansal Classes
Halogen Derivatives
[14]
EXERCISE-II
Q.l (i) (ii) (iii) (iv) (a) (b) (v) (vii) Explain the following giving proper resoning: Treatment of 1,1 -dimethyl oxirane with sodium methoxide in methanol gives primarily one product. Also identify the product giving its IUPAC name Trimethyl amine reacts with alkyl iodide (RI). As the reaction proceeds the reaction rate abnormally increases, inspite of depleting concentration of reactants. Optically active 2-iodo butane on treatment with NaI*/Acetone gives a product which do not show optical activity. In the solvent DMSO the order of reactivity of halide ions with methyl bromide is F~ > Cl > Br" > I~ opposite to that observed in methanol solution. (n - C3H7)3N + CH3I -(n - C3H7)3NCH3+ Relative rate: in hexane, 1; in chloroform, 13000 Br- + CH3OTs-CH3Br + TsORelative rates: in methanol, 1; in HMPT, 105. Although ethers are weakly polar, are used as solvent of choice for Grignard reagents. Treatment of either CH3-CH - CH-CHjBr or CH3-CH -CH - CH2 with aqueous HO~ gives the O O same product. Also write down mechanism involved, & IUPAC name of product. Q.2 (a) (b) (c) (d) (e) Q.3 On reaction between an alkyl halide and KOH in a mixture of water and ethanol, compare the two mechanisms SNj and SN2: relative rates of CH3X,C2H5X,iso-C3H7X&tert-C4H9X relative rates for RC1, RBr and RI effect on rate of a rise in temperature effect on rate of increasing water content of the solvent. effect on rate increasing alcohol content of the solvent. In the following reaction is carried out in the weakly ionizing solvent, acetone (CH3)2C=0. (Bsisbrosyl, p-bromo benzene sulfonyl) n-C4H9OBs + X >n-C4H9X + BsOThe order of reactivity of halide ions depends or the salt used on their source : + ifLi X~ isused,I^r-^Clif (n-C4H))4N+ X - is used C l - > B r - > I ~ How do you account for this contrast in behavior ? Which of the following is the correct method for synthesizing 4,4-dimethyl-pent-2-yne, using sodamide in liquid NH3? Given reasons. CH3 (i) CH3C=CH + CH3 - C - Br CH3 Q.5 (a) Give the products andfindall unknowns. I^N CH2 CH; CH, C ^ Br A > > CH3 (ii) CH3 - C - C = CH + CH3I > CH3
Q.4
faBansal Classes
Halogen Derivatives
[15]
CH3
C2H5O
(b)
CH3-C-CH2-Br CH3 H H
C 2 H 5 OH
Nal
(C)
n
CH, OH
TsCl v * A Pyridine
NaBr
Q.6
(a)
O
H3 +
> A
MgCl
(b)
(c)
Ph-OCl +
(2 eq)
h3o+ c
H - C -OEt + CHgCHjMgBr
(2 eq)
( ) QCMgI + d
(1 eq.) CH2
(e)
HCl
D
E >
H3C
Ph C2H5
To prepare <J>-C-C2H5 by RMgX which is the incorrect pair OH <J)MgBr + (C2H5)2CO C2H5MgBr +
H
H,0
^>C =0
5C2
H
>
[16]
(d)
<f>MgBr + C2H5COOCH3
H2
>
I H
Ci
Q9
I C H 3 - C H - C H - C H 2, - C 1 CH -CI
Zn . Zndust' A n -convert?
What is/are the limitation in the formation of Grignard reagent by RX+Mg dryether > R should not contain any acidic group R should not contain any electronegative group Alkyl halide should not be vicinal dihalide Alkyl halide can't be Tertiary. Identify the unknowns
CH^jCHjCl + 1 ~ - A
(CH3)2CH-Br + KOH (aq.) B (CH3)3C-Br + KCN (ale.) -> C (CH3)3C-Br + KOH (aq.) -> D
CI
CH 3 -CH-CH 2 -OH
Conc NaUH
) E,
Q.12 Write major product of the the following reactions: 0) (ii) Oii) (iv) (v) Q.13
C l C ^ O ^ C H ^ r + KCN PhCHO
SF
>A
* >B ^ >C
Halogen atoms present in CHC13 and CH2 = CHC1 1,1- dibromoethane from 1,2-Dibromethane Chlorobenzenefromchlorocyclohexane o-Chlorotoluenefrombenzyl chloride n-Hexane, CH3CH = CHC1, CH2= CHCH2C1 and O ^ O ^ C I ^ C l
<!SBansal
Classes
Halogen Derivatives
[17]
Q. 15 2-chloro-3-methylbutane on treatment with alcohoilc potash gives 2-methylbutene-2 as major product. Q.16 Iodoform gives precipitate with AgN03 on heating while CHC13 does not. Q.17 Hydrogen atom of chloroform is definately acidic, but that ofmethane is not. Q.18 A small amount ofalcohol is added to chloroform bottles. Q. 19 Treatment of Me3CCH = CH2 and Me3CCHOHMe with concentrated hydrochloric acid gives the same two isomeric alkyl chlorides what are these two products. Q.20 Iodine reacts with alcohols to give alkyl iodine only in presence of phosphorous. Q.21 KCN reacts with R - 1 to give alkyl cyanide, while AgCN results in isocyanide as major product. Q.22 The carbocation F 3 C - C < is unstable whereas carbocation F3C+ismore stable. Q. 23 Dry gaseous hydro halogen acid and not their aqueous solutions are used to prepare alkyl halides from alkenes. Q. 24 RC1 is hydroly sed to ROH slowly but reaction fastens on addition of KI. Q.25 The mechanism of decomposition of Me3 S+ OH" is SN2 whereas of Me3S+1- is SN1. Q. 26 Alkaline hydrolysis ofbenzyl chloride in 50% aqueous acetone proceeds by both ^ 2 and S^l mechanism, when water is used as solvent, mechanism was now mainly SN1. Q. 27 Ethanol is less reactive than methanol as well as isopropyl alcohols when treated with dry HCl gas. Q.28 Anhydrous A1C13 is used as a catalyst infriedelcrafts alkylation. Q.29 Arrange following compounds according to their reactivity with ale silver nitrate. t-Butyl chloride, sec butyl chloride and CCL. Q.30 (a) [ > CH? - OH
^ q)Li a ^ (ii) CuF
+B
- ^ A - ^ B
NBS
J.IMID4 ale.KOH.
1 C
CH, (b) CH3CH2CH2 H (i)TsCl kii)C2HsO"K+ (A) Hi) K kii)C2H5OTs (B) [18] OH
What are (A) and (B) explain giving their stereochemistry. ^Bansal Classes Halogen Derivatives
[ORGANIC CHEMISTRY
XII (ALL)
HYDROCARBON
GR
(1)
X , , hv or UV light or 400 C RX
(2)
(3)
Nitration
R-N
(2)
(3) (4) (5)
Sulphonation H 2 S 2 0 7
S 0 2
G 1 2
Reed reaction^ hv
R S Q
A1CL/HC1 Isomerisation
(6)
Pyrolysis
0
or R-C-R
O
or
RCHO
(7)
+ A1 2 0 3 500C
R-C-R (7)
0
(8)
Z n - H g / C o n e . HCl Clemension's reduction
step up reaction
Higher alkane
CO. + H0
H 2 N-NH 2
Wolf / Kishner reductiori
Combustion
feBansal Classes
HYDROCARBON
[2]
(1)
>R-CH-CH 200-300C
H, Ni
(2)
R-CH-CH-X
(2)
R-CH=CH, or Cn H, 2n
(3) (4) (5) HX
^R-CHX-CH2X
>
R-CHX-CH3
)
R - C H - C H Br
R - C H ( O H ) - C H CI
>
R - C H - C H .
(4)
X (5) R - C (6)
S
dil.H 7 S0 4 (6)
+ H 0
R-CH2(0H)-CH3
(7)
I/2Q 2 Ag300C
.R-CH-CH? O R-CH-CH9
^ ^ COOK RCH-COOK
+ch
2N2
CHO
2
CH
R D
(7) ^
-CH-CH3
'CHO
+
(10)
R-CH.-CH 2
CHO
(11)
(12)
(9)
R-H
Pyrolysis CuR.
0C o4 S v
(10) C H =CHC1
R - CH ,
OH OH jj q
C o
R-CH-CH2 o
(16)
(17)
Ozonolysis
200ChighP Cl2
>
C^H
O O
Polyalkene
(18)
(19)
500C
A1 2 (SQ 4 ) 3 200-300C
(20)
(21) faBansal Classes
HYDROCARBON
(1)
Ni
4 '
>CH,BrCH,Br
J
Peroxide
'
HBr [NoPeroxide C H 3 - C H B r ,
Hoci y CI CHCHO ,
HCN jB a(CN) 2 CH3COOH,Hg'T
)
Zn
6) CH=CH-C1 7)
alc.KOH,NaNH0
(6) (7)
(8)
N
H C - C O Q N a Kolbe's electrolytic synthesis HC-COONa H,0 electric arc, 1200C Berthelot'sprocess (i)Na (ii)R-X
(9)
.CH,CH(HSO,)2
(11)
(12) (13) (14) (15) (16) (17) (18) (19)
>
CH?CHO
(i)CH3Mg!(ii)R-X
Ni,160C
NaNH,
.Na-CsC-Na * Ag-CsC-Ag b
)
Cu-C=C-Cu 2 + H,0
-> H C O O H
CHO CHO
Ozonolysis
I ' o o Trimerisation
> H-C-C-H
+H2Q
~
HCOOH
CH-CH S
CH-CH II II
CH(OCH3)2 CH-,
methylal
HYDROCARBON
[41
EXERCISE-I Q. 1
(A)
The reaction of E-2-butene with CH212 and Zn-Cu Couple in either medium leads to formation of
CH CH,
H
CH, c n , y yci-i?
(D)
(A) Q. 2
H>
CH3/
(A)
CI
(C)
Q3
(E)-3 -bromo-3 -hexene when treated with CH 3 O e in CH,OH gives (A) 3-hexyne (B) 2-hexyne (C) 2.3-hexadiene
(D) 2,4-hexadiene
Q. 4
(a)
Q. 5
GC
(x)L ?
(b>
CC
(y)l
(c
O
(z)
(d)
Q. 6
11
DU
gQ
-> P reaction is
p h
V _ /
C H 3
V
H,C
(C)
'/'C
HYDROCARBON
[5]
Q 7
+Br2
mixture of product. Among the following which product will formed minimum
Br
amount.
(A)
Br
(B) \
ft
(C)
Q.8
H 2
- M ^ P ( M a j o r ) -
(Major)
The structure of Q is
Br Br Br Br
(A)
(B)
(C)
(D)
CH3
M [f
IS (i)CH,COOOH
Q9
hACH3-^^
The probable structure of'X' is
CH,
CH 3
18
(A)
H" (B)HO-
-OH -H CH,
(C)
PhQ
1 0
H,C-
* P(Alkene)
Br, . CC1,
Nal Acetone
Q (Alkene)
Phx H,C
/CH3 Ph CH,3 l Ph
CH3\ Ph
c h
(A) Both
Ph
Ph
(D) Both
CH 3 Ph
Q.ll
faBan sal
Classes
HYDROCARBON
[6]
Q. 12
O-xylene on ozonolysis will give CHO & CH3-C-CHO (A) | CHO CH. - C = O
(Q O
CH3-C = O (B)
C H 3
_I
= 0 &
CH
-O-CHO
o
CH3-C = O
COOCH,
&
CHO
( D )
CHO
0 _ C H 0 &
CHO
3 "
CHO
Q.13
X.
Identify'X'.
,COOCH 3 OH COOCH, OH
(A)
(B) OH
COOCH,
(C)
HO
Q.14
OC2H5
PdCL.HOH CuCi,,0,
^z.
OC 2 H 5 OC 2 H 5 0 0
OC2H5
A; Identify A CH 3 CH 3
OH
(A) CH 3 - C = C - C H , - CH - CH 2
(B) CH 3 - C C - CH 2 - CH = CH, OH
I
OH
CH,
I
CH,
I
(C) C H 3 - C H C OH
I
CH 2 - C H - CH 3 OH
I
l & B a n s a l Classes
HYDROCARBON
[215]
Q, 16
+ CH 2 N 2 (1
equi.)
Pb
(QAc)2
)B;
identify B
(A)S[ Q.17
(B) I
(C)L/J
(D)
1 -Penten-4-yne reacts with bromine at - 80C to produce: (A)4,4,5,5-Tetrabromopentene (B) ].2-Dibromo-l 4-pentadiene (C) 1,1,2,2,4,5-hexabromopentane (D)4,5-dibromopentyne
Q. 18 Compound (A) on oxidation with hot KMnO^/ OH givestwo compound CH3 - CH - COOH & CH3 - C - CH 2 CH 2 CH 3 CH3 compound A will have structure. (A) CH3CH2 - C = C - CH 2 CH 3 CH3 CH3 (C) CH3CH - C CH3 Q.19 Consider the following reaction
k m (A)C 6 H 12 ^ / o h / a >CsH10O In the above reaction (A) will be s
O II
C - CH3
(D) CH 3 CH 2 CH 2 - C = CH 2 CH3
Q.20
f^Jf^
alcoholic KOH
product
o
Q.21
( b ) o f
( c )
0 -
( d )
0 -
Number of required 0 2 mole for complete combustion of one mole of prop ane (A) 7 (B) 5 (C) 16 (D) 10 NOMENCLATURE OFORGANIC COMPOUND [8]
faBansal Classes
Q. 22 How much volume of air will be needed for complete combustion of 10 lit. of ethane (A) 135 lit. (B) 35 lit. (C) 175 lit. (D) 205 lit. Q.23 Q.24 Q.25 When n-butane is heated in the presence of A!Ci3/HCl it will be converted into (A) Ethane (B) Propane (C) Butene (D) Isobutane The reacting species of ale. KOH is (A) OH (B) OR' (C) OK" (D) RO
The product of reaction between one mole of acetylene and two mole ofHCHO in the presence of Cu2Cl2 (A) HOCH, - C = C - CH2OH (B) H2C = CH - C s C - CH2OH (C) HC = C - CH2OH (D) None ofthese PMA polymer is formed by methyl acrylate, which is prepared as follows (A) R - C = CH _coB!L_>
'
Q.26
C +CH3 H
Ni(CO)4
>
(C) HC = CH Q.27
Ni (CO ) 4
During the preparation of ethane by Kolbe's electrolytic method using inert electrodes the pH of the electrolyte (A) Increases progressively as the reaction proceeds (B) Decreases progressively as the reaction proceeds (C) Remains constant throughout the reaction (D) May decrease of the the concentration of the electrolyte is not very high Ethylene forms ethylene chlorohvdrin by the action of (A) Dry HCl gas (B) Diy chlorine gas (C) Solution of chlorine gas in water (D) Dilute hydrochloric acid Anti-Markownikoff's addition ofHBr is not observed in (A) Propene (B)But-2-ene (C) Butene (D) Pent-2-ene
Q.28
Q.29 Q.30
Which alkene on heating with alkaline KMn04 solution gives acetone and a gas, which turns lime water milky(A) 2-Methyl-2-butene (B) Isobutylene (C) 1-Butene (D) 2-Butene Acetylene may be prepared using Kolbe's electrolytic method employing (A) Pot. acetate (B) Pot. succinate (C) Pot. fiimarate (D) None of these
B
<
Q.31
Q.32
Imflar
R-QC-R
Na/NH3
> A
A and B are geometrical isomers (R-CH=CH-R) (A) A is trans, B is cis (B)Aand B both are cis (C) A and B both are trans (D) A is cis, B is trans Q . 3 3 Which is expected to react most readily with bromine (A) CH3CH2CH3 (B) CH2-CH2 (C) CH=CH (D) CH3-CH=CH2 Q. 34 By the addition of CO and 11,0 on ethene, the following is obtained (A) Propanoic acid (B) Propanal (C) 2-Propenoic acid (D) None of the above fa Ban sal Classes HYDROCARBON [9]
Q.35
An alkyne C 7 H 12 on reaction with alk. KMn0 4 and subsequent acidification with HCl yields a mixture CH3-CHCOOH of i + C H , C H 2 C 0 0 H The alkyne is (B) 2~Methyl-3-hexyne (D) 2-Methyl-2-hexene
A compound (C5Hg) reacts with ammonical AgN0 3 to give a white precipitate and reacts with excess of KMn0 4 solution to give (CH 3 ) 2 CH-COOH. The compound is (A) CH 2 =H-CH=CH-CH 3 ' (B)(CH 3 ) 2 CH-CsCH (C) CH 3 (CH 2 ) 2 C=CH (D) (CH 3 ) 2 C=C=CH 2 Which ofthe following reagents cannot be used to locate the position of triple bona in CH 3 -C=C"CH 3 (A) Br2 (B)03
A
Q. 3 7
(C) Cu 2 +
(D) KMn0 4
Q.38
CH 3 -CH 2 -C=CH c
CH 3 C=C-CH 3 (B) NaNH, and alcoholic KOH (D) Lindlar and NaNH 2
A and B are (A) alcoholic KOH and NaNH 2 (C) NaNH2 and Lindlar BH, / THF tr n + A and B are (A)Both<^)-CH2OH
(B)Both^)x-CH3
(C)
C Hj OH, Q - C H ,
(D) Q - C H ,
Q-CH3OH
Q.40
B <
CH3-CS;CH
HgSo 4 /H 2 so 4
A and B a r e O O I I I I
HYDROCARBON
[10]
NaBD,
0 41
product X
Q. 42
CH 2 =CH-CH=CH 2
cc
Mixture of one mole each of ethene and propyne on reaction with Na will form H 2 gas at S.T.P. (A) 22.4 L (B) 11.2 L (C)33.6L (D) 44.8 L Dehydration of 2,2,3,4,4-pentamethyl-3-pentanol gave two alkenes Aand B. The ozonolysis products of A and B a r e O I I
(A)
(B)
CH 3
O
(C)
[219]
NH4C1
Q.45
CH^CH
>
CH 3 - C = GH - C - CH 3 CH 3 O
il
II
Q.47
Alkene A
/H
2 )
C(CH 3 ) 2 ,CH3
^CH, I!
Q.48
HO OH
reagentR,
reagent R,
HO
OH
Q.49
H-C I I HC CH 3
(A) A is meso 1,2-butan-di-ol formed by syn addition (B) A is meso 1, 2-butan-di-ol formed by anti addition (C) A is a racemic mixture of d and /, 1,2-butan-di-ol formed by anti addition (D) A is a racemic mixture of d and 11,2-butan-di-ol formed by syn addition
l&Bansal Classes
HYDROCARBON
[12]
Q.50
/O + C H : M g B r
H30+
^A
Con.H2S04
>
Q 3 /H 2 0/Zn
r.
C F
3
(A)
HO CH 3 CH, O
"HO
(B)
HO CHj CH,
IHCHO CH,
(C)
I
HQ.
I
jCH,
i
CH,
r
CH,
(D)
OOH
Q S 1
'
(C)Et 3 N
(D)t-BuOK
BrCH 2 -CH 2 -CH 2 Br reacts with Na in the presence of ether at 100 C to produce C H 2 - CH2
(A) BrCH 2 -CH=CH 2 (B) CH2=C=CH2 Q. 53 Which has least heat of hydrogenation ( A ) / = \
\ 3
(C) \
( B ) y = y
?
(C
( D ) ^ > =
CH, 3
A.AlSOH 4-CH,
CH,
/ (E) I (B)C
rr-OH
rr-CH,
(A)/
n_ro 3OH
3\
(C)
(D)
HYDROCARBON
[13]
Q. 55
An organic compound ofmolecular formula C4H6, (A), forms precipitates with ammoniacal silver nitrate and ammoniacal cuprous chloride.' A' has an isomer 'B', one mol ofwhich reacts with one mol ofBr2 to form 1,4-dibromo-2-butene. Another isomer ofA is ' C \ one mole of C reacts with only 1 mol. of Br, to give vicinal dibromide. A, B & C are (A) CH 3 -CH 2 -OCH and CH 2 =CH-CH=CH 2 ; f j | (B) CH 3 -C=C-CH 3 and CH 3 -CH=C=CH 2 ; CH 3 -C=C-CH 3 CH2-CH CH9\ (C) I ~ . O C H , and ; CH2 = CH-CH=CH 2 CH2-CH CH,/
(D) C H 3 - C S C - C H 3 and C H 2 -CH. | CH2 ; CH 2 = C H - C H = C H 2
^CH^
Q.56
CH 3 -CH=CH-CH 3 product is Y (non-resolvable) then X can be cis (B) H C 0 3 H (A) Br2 water (D) all of the above (C) Cold alkaline KMn0 4 Electrophilic addition reaction is not shown by (A) CH2 = C - CH3 and Br2 CH 3 (C) CH 3 -CsCH and CH3MgBr (D) CH2=CH2and dil. H 2 S0 4 solution (B) CH=CH2 and HO-C1
Q. 5 7
Q. 5 8
A mixture of CH4, C 2 H 4 and C 2 H 4 gaseous are passed through a Wolf bottle containing ammonical cuprous chloride. The gas coming out is (A) Methane (B) Acetylene (C) Mixture of methane and ethylene (D) original mixture In the presence of strong bases, triple bonds will migrate within carbon skeletons by the (A) removal of protons (B) addition of protons (C) removal and readdition of protons (D) addition and removal of protons. CH 2 =CH-CH=CH 2 + CHCOOH CHCOOH Diels Alder
Q. 5 9
Q.60
COOH
COOH
a
(D)
Friedel-Crafts
COOH COOH
( Q l O i .
y^yCOOR
COOH
Diels Alder
Friedel-Crafts
COOH
fa Ban sal
Classes
HYDROCARBON
[14]
Q. 61
For the ionic reaction of hydrochloric acid with the following alkenes, predict the correct sequence of reactivity as measured by reaction rates: (I)C1CH=CH2 (1I)(CH3)2.C=CH2 (in) OHC GH=CH2 ^V)<NC)2C=C(CN)2 (A) IV > I > III > II (B) I > IV > II > III (C)III>II>IV>I (D) II > I > III > IV The addition of bromine to 2-cyclohexenyl benzoate in 1,2-dichloroethane produces derivatives: (A) 2 (B)3 (C)4 (D)6 How many products will be formed when methylenecyclohexane reacts with NB S? (A) 3 (B)l (C)2 (D)4
CH3-C-NH2
Q. 62
dibromo
Q. 63
Q.64
/ > ~ B r - Mg/drycther^pQ
^(Y)
The structures of (X) and (Y) respectively are (A) X = < V-MgBr ; Y=< VoH
; ;
Y= Y = HOOH
faBansal
Classes
HYDROCARBON
115]
EXERCISE-I (B)
Q.l
A
HgS04/H2SQ4 ^
BH,/THF H 2 O 2 /OH
(Q
(D)
An alkene on ozonolysis yields only ethanal. There is an isomer of this which on ozonoly sis yields: (A) propanone (B) ethanal (C)methanal (D) only propanal CH 3 - CH = CH-CH, + CH 2 N 2 ~ > A A can be
Q.3
(A) Q.4
(C)
Aqueous solution of potassium acetate is electrolysed. Possible organic products are: (A) n-Butane (B) C 2 H 5 COOC,H 5 (C) CH 3 -CH 3 (D) CH 2 =CH 2
Q.5
HO
Re agent R2
Reagent R,
HO
OH
R, and R 2 are: (A) cold alkaline KMn0 4 , 0 s 0 4 / H 2 0 2 (B) 0 s 0 4 / N a H S 0 3 ; A g 0 2 , H 3 0 (C) cold alkaline KMn0 4 , C 6 H 5 C 0 3 H / H 3 0 (D) C 6 H 5 C 0 3 H ; 0 s 0 4 / NaHS0 3 Q.6
H2/Pt (A) C 4 H 6 > (B) C 4 H g -> CH 3 COOH Hence A and B are (A) CH 3 C = CCH 3 , CH 3 CH = CHCH 3 (B) CH 2 = CHCH 3 = CH 2 , CH 3 CH = CHCH 3
(C) Q. 7
CH 3 CH = CHCH 3
(D) None
Which is / are true statements/ reactions? (A)A14C3 + H 2 0 > C H 4 (C) Mg 2 C 3 + H 2 0 > CH 3 C =CH P H - C - CH,
O
Q.8
Ph-CH 2 -CH 3
A could be: (A) NH 2 NH 2 , glycol/OH (C) P/HI (B) Sn(Hg)/conc. HCl (D) CH 2 - CH 2 ; Raney Ni - H ^ SH SH [16]
HYDROCARBON
Q.9
BuOK
>Product
which is / are correct statements about the product: (A) (B) (C) (D) Q.10
C
-CH,
is an endocyclic Saytzeff product is an exocyclic Saytzeff product is an exocyclic Hoffmann product is an endocyclic Hoffmann product
NBS
a
C V
CH, CH,
H
Q.ll
Which are correct statements? (A) meso-1, 2-dibromo-butane on reaction with Nal / acetone gives trans-2-butene (B) d-or /-1,2-dibromobutane on reaction with Nal/acetone gives cis-2-butene (C) meso -1,2-dibromo-butane on reaction with Nal / acetone gives cis-2-butene (D) d-or/-1,2-dibromobutane on reaction with Nal/acetone gives trans-2-butene Ph-CH-CH 2 + BrCCl, Product is: H (A) PhBr Br (C) PhH CH2CC13 (D) Ph-CH2CC13 (B) PhH - CH?Br CCI3 CCI3 CH2Br P^oxide
)
Q.12
HYDROCARBON
[17]
Q.13
Which of the following elimination reactions will occur to give but-1 -ene as the major product? (A) (B) CH3.CHCl.CH2.CH3 + KOH CHvCH,.CH.CH,+NaOEt NMe3 (C) (D) CH3.CH2.CHC1.CH3 + Me3CoK CH3.CH2.CH(OH).CH3 + conc.H 2 S0 4
EtOH
The above compound undergoes ready elimination on heating to yield which ofthe following products?
(A) O C h , x
Me-^ Q.15
Me "
<B) O
Me^ ^Me
(C)
Me^ ^Me
(D)
Me^
^Me
Which of the following will give same product with HBr in presence or absence of peroxide. (A) Cyclohexene (B) 1-methylcyclohexene (C) 1,2-dimethylcyclohexene (D) 1-butene The ionic addition of HCl to which of the following compounds will produces a compound having CI on carbon next to terminal. (A)CF3.(CH2)3.CH=CH2 (B)CH3.CH=CH2 (C) CF 3 .CHCH 2 (D) CH3.CH2CH=CH,.CH3 Select true statements): (A) I2 does not react with ethane at room temperature even though ^ is more easily cleaved homolytically than the other halogens. (B) Stereochemical outcome of a radical substitution and a radical addition reaction is identical. (C) The rate of bromination of methane is decreased if HBr is added to the reaction mixture. (D) Allylic chloride adds halogens faster than the corresponding vinylic chloride. Select true statements): (A) Instead of radical substitution, cyclopropane undergoes electrophilic addition reactions in sun light. (B) In general, bromination is more selective than chlorination. (C) The 2,4,6-tri-tert, butylphenoxy radical is resistant to dimerization. (D) The radical-catalysed chlorination, ArCH3 ~>ArCH2Cl, occurs faster when Ar = phenyl than when Ar = p-nitrophenyl.
Q.16
Q.17
Q.18
Q. 19 Nitrene is an intermediate in one of the following reactions: (A) Schmidt rearrangement (B)Beckmannrearrangement (C) Baeyer-Villiger oxidation (D) Curtius reaction Q. 20 Which reagent is the most useful for distinguishing compound Ifromthe rest ofthe compounds
CH 3 CH 2 CSCH CH 3 CSCCH 3 CH3CH2CH2CH3 CH3CH=CH2
n (B)Br2/CCl4
Q.21 In most ofthe rearrangements, the migrating group migrates with (A) inversion of its configuration (B) retention of its configuration (C) racemization of its configuration (D) retention of its structure Q.22 Indicate among the following the reaction not correctly formulated. (A) CH2=CH-CH3 > O^Cl-CHCl-CHG HC^X > I I N
HC y
1-1
(B) HCsCH+CH^
photo
haiogenation
~ > (CH3)3C-C1 as major product J><CH2_CH2_CH3 List II (1) Substitution reaction (2) Elimination reaction >
(D) CHJ-C^C-CHJ-C^-CHJ Q.23 (A) n-Hexane (B) CH s CH CH3 (C)CH3-C- X I CH3 (D) CH3-CH2-X > aq. List I Cr203-Ai203,A ^
RedhotFetube
(3)Aromatisation
(4) Cyclization
faBansal Classes
HYDROCARBON
[19]
Q.24
|
List n
(ii)H 2 0 2 /0H
% )
(1) CH 3 -CH2-CH=CH2
^QAVHOH)
(ii)NaBH4
(2) CH 3 -CH=CH-CH 3
(C) CH 3 - CH 2 - CH - CH 3
CHJONA/A
(3) C H 3 - C H - C H 2 O H CH.
CI
OH
(CH
(D) C H 3 - C H 9 - C H - C H ,
3)3CONA
(4) C H 3 - C - C H 3 CH.
I
A 4 4 3 3
B 3 3 4 4
C 1 2 2 1
D 2 1 1 2
Q.25
List I (A) Walden Inversion (B) Racemic mixture (C) Alkene (D) Alkene Codes: (a) (b) (c) (d)
Baeyer
Listn
(1) Cis addition (2) Trans addition (3) SN, reaction (4) SN 2 reaction A 3 3 4 4 B 4 4 3. 3 C 2 1 1 2 D 1 2 2 1 List n (1)Na/NH 3 (/) (2)H 2 /Pd/BaS0 4 (3) ale. KOH, A (4) NaNHj , A C 3 4 3 4 D 4 3 4 3 [20]
>
Q.26
List I (A) CH 3 -C=C- CH 3 c i s - 2 - b u t a n e (B) C H 3 - C = C - C H 3 >trans-2-butane (C) CH 3 C=C-CH 3 > 1-Butyne (D) C H 3 - C H 3 - C = C H 2 - B u t y n e A B Codes: 2 1 (a) 1 2 (b) 1 2 (c) 2 1 (d)
l&Bansal Classes
HYDROCARBON
List I
electrolysls
(1) Corey-Housh reaction (2) Kolbe electrolysis (3) Oakwood degradration (4) Hunsdiecker reaction C 4 4 3 1 D 1 2 2 3 Listn CH2-CH3 (1) Birch reduction
Soda lime
(i)AgNO, (ii)CI2/A
R-Cl
(D) R'-X + R^CuLi Codes: (a) (b) (c) (d) Q.28 ListI 0
> R-R' A B 2 3 1 3 4 2 2 4
C CH, (A)
(2) Coupling of reactants is taking place > 2,2,3,3 tetramethyl butane(3) A1CL + HCl at 3 00C (4) Polymerisation > n-Butane (5) Aromatic procducts is formed (6) Zn + A used as reagent (7)Al203 at high temperature
faBansal
Classes
HYDROCARBON
[21]
List I
Baeyer
List n (1) Neighbouring group participation seen (2) Markovnikov's rule is followed. (3) Cis isomer formed (4) Syn addition
>?
(B)Alkene-^>?
(Q =~ H 2 Pd. . >9 BaSO.
PhC 3H
(D) Alkene
>?
CH, (6) Racemic mixture in case of But-2-ene (cis) (7) Meso compound in case of But-2-ene (cis)
HYDROCARBON
[22]
EXER CISE-II
Q.l Give the product of (a) f
W
R ^ V ^ I / THF
T > V
>
CH 3
Q-2 CH3-C-C1
LlA1H
* >
CH 3
Q. 3
Q.4
2 H 5 \c /
H
= c
/C2H5 , \
H
T RF RN I 3 3
2. H,OZH+
> A+B.WhatareAandB?
Q.5
D Y H Br O I I CH.
k M
Na H
ALC
O I I .CH
Q. 6
NO 2 -CH 2 CH
^c=c ^
CH 2 -NO 2
Q.7 Q.8
j'
Q. 9
Give the structure of the alkene that yields on ozonolysis (i) CH3CH2CH2 CHO & HCHO (ii) C 2 H 5 COCH 3 & CH 3 CH(CH 3 ) CHO (iii) Only CH3CO.CH3 (iv) CH 3 CHO & HCHO & OHC CH2.CHO (v) Only OHC-CHjC^CH^-CHO. One ofthe constituent ofturpentine is a-pinene having molecular formula C 10 H, 6 . The following scheme give reaction of a-pinene. Determine the structure of a-pinene & of the reaction products Athrough E. E(C 10 H 18 O 2 ) A(C 10 H 16 Br 2 ) T t^O t.Br 2 /CCl 4 C 10 H 16 O(D) < phC03H a -pinene o >B (C 10 H 1? OBr)
0s04
F
'H2
HYDROCARBON
[23]
Q.10
>D
'
CH3(CH;)3-CH(K
KOII, ILO
A Na
2, H,0+
RSO/.A
*.
0,/H,o
What are A to K for the following reactions PhC = CH + CH3MgX -> A PhCHjCHjCHg + Br2 >D CH, Me Me H3C OH OH ^ a
)
g
- E
u/nh,
r
hot KMnQ4 vOH ^ Q
(Mi)
(iv) OH
(v)
CF3 - CH = CH2 Me Me
(!lBansal
Classes
HYDROCARBON
[24]
(i)
\
+
A COjMe
->
(" ')
I
A
Ph o l.NaNH2(3equiv.)NH3 ^ g 2. CH3I
Q 14 (i) Compare the reaction of CH2 = CH, & CF2 = CF2 with NaOEt in EtOH (ii) CC1, = CC12 does not decolourise Br2 solution - explain. Q.15 (i) (ii) Account for the collowing facts Ozonolysis if carried out in MeOH solvent a hydroxy peroxy ether is formed as unexpected product. When 2,3 dimethyl 2 butene is treated with 0 3 in presence ofHCHO in CH,C12 medium, an ozonide other than that expected of the starting alkene is formed. Identify the unexpected ozonide.
Q.16 Explain the following: (i) 1,2 shift does not take place during oxymericuration demercuration. Why? (ii) Halogneation of alkene is anti addition but not syn addition. Why? (iii) Anti markovnikov addition is not applicable for HCl. Why? (iv) 1,4-addition hikes place in butadi-ene. Why? (v) C-H bond is stronger than C-C bond but in chlorination C-H bonds get cleaved but not C-C bond. Why? Q.17 Conversion: (i) C2H2 racemic 2, 3 dibromobutane (ii) 2 butyne (iii) Ethyne Acetone (iv) Methane > n Butane Conversion: (i) C2H2 > ethylidene diacetate (iii) C,H, > m nitroaniline > 2 pentyne (v) Ethene
Propionic Acid
Q.18
(ii) C ^ -> Butyne diol (iv) cis but 2 ene > Trans but 2 ene
Q.19 Q.20
Outline a stereospecific synthesis of meso 3,4 dibromohexane from ethyne. How can you convert (a) Ethane in to meso 2,3 dimethyl oxiran (b) CaC, into 1,3. 5 hexatriene (c) Trimethylsecbutyl amonium hydroxide into 1,4-butan-dial (d) Cyclo hexanol into trans cyclo hexane-1,2-diol How will you conver (a) Hexane dial into 1,3,5 hexatriene (b) 1 -methyl propyl ethanoate into 1,4-dichloro-2-butene Classes HYDROCARBON
Q.21
fa Bansal
[25]
Q.22
Me2C = CH - CH 2 CH 2 CMe = CHCHO + H 3 0 Citral Q.23 When citral is allowed to react in presence of dilute acid with olivetol, there is obtained a mixture of products, one of which is drug marijuana. Reaction is as follows.
Me2C = CH - CH2-CH2-CMe=CH-CHO +
[ q !
O H ^ ^ Q H ,
\
\ _
q
(0/~C'H"
)
(marijuana) Explain the mechanism. Q.24 The following cyclisation has been observed in the oxymercuration & demercuration of this unsaturated alcohol. Propose a mechanism for this reaction.
2. NaBH 4
Q.25 Write the structural formula oflimonenefromthe following observation: (a) Limonene when treated with excess I-^&Pt catalyst, the product formed is 1 isopropyl 4 methyl cyclohexane (b) When it is treated with 0 3 & then Zn/H20 the products ofthe reaction are HCHO & following compound
Q.26
(a)
MeCH2-C=CBr + CH=CMe
CI
Cu+
> A
(b)
CH 2 -CHC1 2 OH
0H
>B
(c)
(d)
CH2 = C H - C H - C H = C H - C H , l e O H > C
H2S04 /
\
\C=CH
/ H2SO4/H2O
(e)
C13C-CH=CH2
HQBr
rS
>
(0
/ - Y *
OH
> F
3Z"20
>
G
[26]
HYDROCARBON
Acetylene is acidic but it does not react with NaOH or KOH. Why? CH=C-CH 2 -CH=CH 2 , adds up HBr to give CH^C-CH 2 -CHBr-CH 3 while CH=C-CH=CH2 adds up HBr to give CH2=C . Br . CH=CH2. Chlorination of ethane to ethyl chloride is more practicable than the chlorination of n-pentane to 1-chloropentane. Why 11-pentanehas higher boiling point than neopentane? EXERCISE-HI 0.37 gm of ROH was added to CH3MgI and the gas evolved measured 112 cc at STP. What is the molecular wt. ofROH ? On dehydration ROH gives an alkene which on ozonolysis gives acetone as one of the products ROH on oxidation easily gives an acid containing the same number of carbon atoms. Gives the structures ofROH and the acid with proper reasoning. An alkane A (C 5 H, 2 ) on chlorination at 3 00 gives a mixture four different mono chlorinated derivatives B, C, D and E. Two of these derivatives give the same stable alkene F on dehydrohalogenation, On oxidation with hot alkaline KMn0 4 followed by acidification ofF gives two products G and H. Give structures ofA to H with proper reasoning. There are six different alkene A, B, C, D, E and F. Each on addition of one mole ofhydrogen gives G which has the lowest molecular wt hydrocarbon containing only one asymmetric carbon atom. None of the above alkene give acetone as a product on ozonolysis. Give the structures of A to F. Identify the alkenes that is likely to give a ketone containing more than five carbon atoms on treatment with a warm conc, solution of alkaline KMn0 4 . 3,3-dimethyl-1 -butene and HI react to give two products, C 6 H, 3 I. On reaction with ale, KOH one isomer, (1) gives back 3,3-dimethyl-l-butene the other (J) gives an alkene that is reductively ozonized to Me 2 C=0. Give the structures of (I) and (J) and explain the formation of the later. Three isomeric alkenes A, B and C, C5HR) are hydrogenated to yield 2-methvlbutane A and B gave the same 3 ROH on oxymercuration - demercuration. B and C give different 1 ROH's on hydroboration -oxidation. Supply the structures of A, B & C. Two isomeric alkyl bromides A and B (C5H, ,Br) yield the following results in the laboratory. A on treatment with alcoholic KOH gives C and D (C 5 H, 0 ). C on ozonolysis gives formaldehyde and 2 methyl propanal. B on treatment with alcoholic KOH gives only C (C 5 H ]0 ). Deduce the structures of A, B, C andD. Ignore the possibility of geometrical and optical isomerism. Give the structure of A, B and C. A. (C4Hg) which adds on HBr in the presence and in the absence of peroxide to give the same product C4H9Br. B (C4H8) which when treated with H 2 S0 4 / H 2 0 give (C4H10O) which cannot be resoslved into optical isomers. C (CgH12), an optically active hydrocarbon on catalytic hydrogenation gives an optically inactive compound CfiH,4. An alkylhalide, X, of formula C 6 H )3 Clon treatment with potassium tertiary butoxide gives two isomeric alkenes Y and Z (C6H,2). Both alkenes on hydrogenation gives 2,3-dimethylbutane predict the stmctures ofX, YandZ. Identify a chiral compound C, C, 0 H. 4 , that is oxidized with hot KMn0 4 to Ph COOH, and an achiral compound D, C lt ,H ]4 , inert to oxidation under the same conditions. HYDROCARBON [27]
Q. 1
Q.2
Q.3
Q.4
Q. 5
Q.6
Q.8
Q.9
Q.10
C7H14 (A) decolorises Br2 in CC14 and reacts with Hg(OAC)2 in THF. H 2 0 followed by compound (C) obtained by oxidation of 3-hexanol with KMn0 4 . Identity A, B and C compound D, and isomers of A reacts with BHV THF and then F I ^ / O H to give chiral E. Oxidation of E with KMn0 4 or acid dichromate affords a chiral carboxylic acid F. Reductive Ozonolysis of D, gives the F and G.
4
'
Q.ll
Q.13
A hydrocarbon A, ofthe formula CgH10, on ozonolysis gives compound B (C4H602) only. The compound B can also be obtained from the alkylbromide (C3H5Br) upon treatment with magnesium in dry ether, An organic compound (A), C6H10 on reduction first gives (B), C6H12 and finally (C), C H [4 . (A)
Q.14
Q.15
Compound A (C6H]2) is treated withBr2 to form compound B (C6H12Br2). On treating B with alcoi KOH followed by NaNH, the compound C (C6H10) is formed. C on treatment with H2/Pt fo 2-methylpentane. The compound ' C does not react with ammonical Cu2Cl2 or AgN0 3 . When treated with cold KMn0 4 solution, a diol D is formed which gives two acids EandF when heatec KMn04 solution. Compound E is found to be ethanoic acid. Deduce the structures fromAto F. (A) give snoj>pt. with Ag(NH 3 V andgfves optimally inactive (CX C 8 H, 4 ^ t h Hjnpreser
OF)'
"d fi d K M n O ^ ^ ^
'
V 6 S m
C2l 4
J ^
f E ) C
f f
0xidati
no^B)
Q.17 A
Oxidation ofB wi
HYDROCARBON
[28]
Q.20
6g sample of a natural gas consisting of methane (CH4) and ethylene (C2H4) was burned with excess of oxygen and 17.2g of carbon dioxide and some water was obtained as products. What percent by weight of the sample was ethylene.
EXERCISE-IV
Q. 1
(A)
[IIT4 90]
Alcoholic solution ofKOH is a specific reagent for (A) Dehydration (B) Dehydrogenation (C) Dehydro halogenation ' (D) Dehalogenation Of the following, unsaturated hydrocarbons are (A) ethyne (B) cyclohexane (C) n-propane 1 -chlorobutane on reaction with alcoholic potash gives (A) 1-butene (B) 1-butanol (C) 2-butene (D) ethene
Q.2 Q. 3
Q4
The hybridisation of carbon atoms in C-C single bond ofHCsC-CH=CH 2 is (A) sp3-sp3 (B)sp 2 -sp 3 (C) sp-sp2 (D) sp2-sp2 The product(s) obtained via oxymercuation (HgS04 + H 2 S0 4 ) of 1-butyne would be (A) CH3 - CH2 - C - CH ,
II o
Q.5
When cyclohexane is poured on water, itfloats,because [IIT' 97] (A) Cyclohexane is in 'boat' form (B) Cyclohexane is in 'chair' form (C) Cyclohexane is in 'crown' form (D) Cyclohexane is less dense than water Which ofthe following compounds will show geometrical isomerism? [IIT '98] (A) 2-butene (B)Propene (C) 1-phenylpropene (D) 2-methyl-2-butene In the compound CH2=CH-CH2-CH2-C=CH, the C 2 -C 3 bond is ofthe type (A) sp-sp2 (B) sp3-sp3 (C) sp-sp3 (D) sp2sp3 [IIT4 99]
Q.7
Q.8
Q. 9
Which one ofthe following alkenes will react fastest with H2 under catalytic hydrogenation condition [IIT '2000]
R
(A) ; > = (
H
yH
R \
H H
R \
CD) /
R
R \
Q. 10 Propyne and propene can be distinguished by (A) conc H 2 S0 4 (B) Br, in CC14 (C) dil. KMn0 4 Q. 11
In the presence of peroxide, hydrogen chloride and hydrogen iodide do not give anti-Markovnikov addition to alkene because [T1TS42001] (A) both are highly ionic (B) one is oxidising and the other is reducing (C) one of the step is endothermic in both the cases (D) All the steps are exothermic in both cases HYDROCARBON [29]
(B) An optically inactive (D) Adiastereomeric mi? Q.13 The reaction of (A) H+ (C) OH
I HOC! I
[IIT'2001]
[IIT'2001J
Q.14
Q.15
(B) H 3 C - C H - C - C H 3
J u ,
(C) H 3 C - C - C H - C H 3
(D) H 3 C ~ C H - C H - C H 3
1,
Q.16
(B)H2J
( A ) N A @
(B)Y-<o)
HYDROCARBON
[30/
Q.18
OH
" _H
H+
(mixture)
> 5 compounds of molecular formula C4H8Br2 |1IT'20031 (C) 4 (D) 5 [IIT' 2004] (D) NaBH 4
2-hexvne can be converted into trans-2-hexene by the action of: (A) H 2 -Pd-BaS0 4 (B) Li in liq. NH3 (C)H 2 -Pt0 2
Q.20
When Phenyl Magnesium Bromide reacts with tert. butanol, which of the following is formed? (A) Tert. butyl methyl ether (B) Benzene (C) Tert. butyl benzene (D) Phenol [IIT '2005] 1 -bromo-3 -chlorocyclobutane when treated with two equivalents ofNa, in the presence of ether which ofthe following will be formed? [IIT'2005] /Br (A) (B) /CI
( C ) [ J
(D)
Q.21
Q. 22
Cyclohexene is best prepared from cyclohexanol by which of the following: (A) conc. H 3 P0 4 (B) conc. HCl/ZnCl2 (C) conc. HCl (D) conc. HBr [ET '2005]
Q.23
[IIT 2006]
(D)
NO
CI
2'hv
fractional
distillation
M(isomeric products)
(B) 6, 4
(C) 4, 4
(D) 3, 3
[IIT 2006]
i&Bansal Classes
HYDROCARBON
[31]
EXERCISE-IV
CI
(B)
[IIT 1992!
Q.l
^ Q.2
[ I I T 19931
Br Q. 3 an optically active hydrocarbon which on catalytic hydrogenation gives an optically inactive compound, C 6 H,. [IIT 1993]
C ( C 6 H j 2 ),
Q. 4
[IIT 1994]
Q. 5
Write down the structures of the stereoisomers formed when cis-2-butene is reacted with bromine.
[ I I T 1995]
Q.6
An organic compound E(C 5 Hg) on hydrogenation gives compound F(C5H12). Compound E on ozonolysis gives formaldehyde and 2-ketopropanal. Deduce the structure of compound E. [IIT 1995] Give the structures of the major organic products from 3-ethyl-2-pentene under each of the following reaction conditions. [IIT 1996] HBr in the presence of peroxide (b) B^/F^O Hg(0Ac) 2 /H 2 0;NaBH 4 An alkyl halide, (X) offormula C6H13C1 on treatment with potassium tertiary butoxide gives two isomeric alkenes (Y) and (Z) (C 6 H ]2 ). Both alkenes on hydrogenation give 2,3-dimethylbutane. Predict the structures of (X), (Y) and (Z) [ITT 1996] 3,3-Dimethyl-butan-2-ol loses a molecule of water in the presence of concentrated sulphuric acid to give tetramethylethylene as a major product. Suggest a suitable mechanism. [IIT 1996] One mole of the compound A (molecular formula C8H12), incapable of showing stereoisomerism, reacts with only one mole of H 2 on hydrogenation over Pd. A undergoes ozonolysis to give a symmetrical diketone B (C 8 H 12 0 2 ). What are the structure ofA and B? [IIT 1997] Compound (A) C 6 H 12 gives a positive test with bromine in carbon tetrachloride. Reaction of (A) with alkaline KMn0 4 yields only (B) which is the potassium salt of an acid. Write structure formulae and IUPAC name of (A) and (B). [UT 1997] The central carbon-carbon bond in 1,3-butadiene is shorter than that of n-butane. Why?
[ I I T 1998]
Q.9 Q. 10
Q. 11
Q.12 Q.13
[IIT 1998]
Q 14
[IIT 1998]
fa Ban sal
Classes
HYDROCARBON
[32]
Q.15 Q.16
Discuss the hybridisation of carbon atoms in allene (C3H4) and show the 7i-orbital overlaps [IIT 1999] Complete the following [IIT 1999]
Q.17
[IIT 1999]
HO A . > H 3 CC N 3 / CH 3 CH 3
c h
/=c\
D /
Q.18
Explain briefly the formation on the products giving the structures of the intermediates.
C H r,
[IIT 1999]
OH
+ I
2 \ /CH~CH
- C l + etc.
(ii)
H,C
Explain the non formation of cyclic product in (ii) Q.19 Carry out the following transformation in not more than three steps.
O
| HI' 1999]
CH,-CH 2 -C=C-H -> CH 3 - CH, - CH 2 - C - CH, Q.20 Q.21 CH2=CH is more basic than HC=C What would be the maj or product in each of the following reactions?
CH,
CH3-C-CH,Br
' '
C2H5OH
CH,
(ii)
CH,
H, Lindlar'sCatalyst
Q.22
On reaction with 4N alcoholic KOH at 175 C 1-pentyne is slowly converted into equilibrium mixture of 1.3% 1-pentyne (A), 95.2% 2-pentyne (B) and 3.5% 1,2-pentadiene (C). Give the suitable mechanism of formation ofA, B and C with all intermediates. [IIT 2001] Identify X, Y and Z in the following synthetic scheme and write their structures. Is the compound Z optically active? Justify your answer. [IIT 2002] CH3CH,C-=-C-H
(i) NaNH2 ^ ^ (ii)CH3CH2Br H2/Pd-BaSQ4 ^ y alkaline KMnQ4 ^ j
Q.23
fa Ban sal
Classes
HYDROCARBON
[33]
A biologically active compound, Bombykol (C ]6 H 30 O) is obtained from a natural source. The structure of the compound is determined by the following reactions. On hydrogenation, Bombykol gives a compound A, C 1 6 H 3 4 0, which reacts with acetic anhydride to give an ester. Bombykol also reacts with acetic anhydride to give another ester, which on oxidative ozonolysis ( 0 3 / H 2 0 2 ) gives a mixture of butanoic acid, oxalic acid and 10-acetoxy decanoic acid. Determine the number of double bonds in Bombykol. Write the structures of compound Aand Bombykol. How many geometrical isomers are possible for Bombykol? j LIT 2002J If after complete ozonolysis of one mole of monomer of natural polymer gives two moles of CH2Q
Q.25
andone mole of O = C - CH = 0 . Identify the monomer and draw the all-cis structure ofnatural polymer. [IIT 2005]
Identify X and Y.
[IIT 2005]
^Bansal Classes
HYDROCARBON
[34]
ANSWER KEY
EXERCISE-I Q.l Q.8 Q.15 Q.22 Q.29 Q.36 Q.43 Q.50 Q.57 Q.64 B C B C B B B A C C Q.2 Q.9 Q.16 Q.23 Q.30 Q.37 Q.44 Q.51 Q.58 A C B D B A B A C Q.3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 Q.52 Q.59 A C D A C A B C C Q.4 Q.ll Q.18 Q.25 Q.32 Q.39 Q.46 Q.53 Q.60 D D B A A D A C A (A) Q.5 Q.12 Q.19 Q.26 Q.33 Q.40 Q.47 Q.54 Q.61 (B) A,B,C,D A,B,C A,B A,C A,D Q.4 Q.8 Q.12 Q.16 Q.20 A,B,C,D A,B,C,D A,C A,B,D D A A D B D B C C D Q.6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 Q.55 Q.62 A B B A A B B A A Q.7 Q.14 Q.21 Q.28 Q.35 Q.42 Q.49 Q.56 Q.63 C A B C B A A C A
EXERCISE-I Q.l Q.5 Q.9 Q.13 Q.17 Q.21 Q.23 Q.26 Q.29 Q.2 A,C A,C Q.6 A,B B,C Q.10 A,B A,C Q.14 B,D B,C Q.18 B,C,D A,C,D Q.22 A,C,D B,D (A) 3,4 ; (B) 3,4 ; (C) 1,2;(D)2 Q.27 (a) (d) (A)5,7 ; (B) 4,5 ;(C) 3 ; (D) 1,2,6 Q.3 Q.7 Q.ll Q.15 Q.19 Q.24 Q.28 Q.30
Q.25 (c) (c) (A) 4; (B) 3; (C) 1; (D) 3,4 (A) 4,7;(B)5,6; (C)3,4; (D)5,6 ; (E)2
coo w
-D + DHCOO -H -OD -H
(b)
DOCOO
O = CH
+
n_CH=i 0 CH=
C,H<
O = CH
-H -OH C?H=
Q.4
OH-
"H
Q.7
CH 2 = C H - C H 2 - C H 2 - C H 2 - N - C H 3 CH 3
c
Q.8
Q.9
a-pinene ->
(A) =
V ^ ^ B r , (B) =
Me
Br
(C) =
Me
0 H
^ / V ^ r
OH Q.10
ONa
(A) c _ c _ c _ c , (B) C - C - C - C, (C) C - C - C - C - O - C - C , (D) BrMg-C-C-C-C (E) C-C-C-C-C-C-C-C-C,(F)C-C-C-C=C-C-C-C-C, OH Br (G) C - C - C - C - C - C - C - C - CV(H) C - C - C - C s C - C - C - C - C Br C-C C-C C-C
Q.ll
Q.12
Phv c H /
= c
/H Ph-CH-Et \ c H _ A r ,(D) ^
OH
HYDROCARBON
[36]
Q.13
(i)
/ ^ L
> (iv)noreaction
W(A)p
_l
C H 2
B r
,(B)Ph-C,C^H
Q. 14
Q.25
CI
I , ( Q CH 2 = CH - CH == CH - CH - CH,
0 ( )A/\/\A G 0
(D) <^JyC-CH3
Ii
OH I
Q.l
H 13 C \ > H3C/
CH-CH,OH
Q . 2 (A)
(B)
CH3 I HjC-CH-C^CHjCl
(C)
(D)
<F)
(G) (B)
(H) (C)
Q.3 (A)
CHXHXH, CH 2 =C-CH ; CH 3
(D)
CH 2 -CH=CH 2
(E)
(G)
CH,-C=CH-CH 3
C^CHjCHj I
(F)
CHXH^CH^ I CH 3 -CH-CH=CH 2
fa Ban sal
Classes
HYDROCARBON
[37]
Q.4
(I)
CH3 I
(J)
CH3 CH3 I I I I
CH3-C- CH-CH3
CH3CH-C-CH3
I I Q.5
I CH3 (B)
CH2=CCH2CH3 I CH,
(C)CH2=CHCH(CH3)2
(B) s
CH^r-CH^-CH-CI^ CH,
(Q
CH2=CH-CH-CH3 CH3
(D)
Q.7 (A)
:c=c
(Q
(Z)
Q.8
(X)
CH2=C CH-CH3
Q.9 Q.10
(A)PhCH(CH3)CH2CH3
(B)PhC(CH3)3 OH
(D)
CH3
(E)
CH3-CH-C-CH2CH3 II CH2 (G) CHJ-CH- C-CH 2 -CH 3 I II CH3 0 Q.LL Q.12 (A) C^CH^CH^-CHCH, CH3
(F)
(C) Cvclopentene
P ) H,C-C-C=CH-CH2CH2CH3 CH,
faBansal Classes
Q.13 Q.14
(A)[>-OC^j
(B)[>-COOH
(C)[>-Br
Q.15
(C)
CH 3 -C=C-CH-CH 3 CH3
H 3 C-CH-COOH I C^
Q.16
Q.17 Q.18
(C) C H 3 - C H 2 - C H 2 - C H 2 ~ C H 2 - C H 3 ,
Q.19
Isomer are : C ^ C - C - C , C = C - C = C , C = C = C - C ,
(A)
Q.4 Q.9 Q.14 Q.19 Q.24 C A A B B Br (L,H-CH9-CH3 Q.5 Q.10 Q.15 Q.20 A D B B
EXERCISE-IV
CH 2 -CH-CH 3 Q.l CH, - C = C H - C H , CH3 Q.2
(B)
CH=CH-CH, * F O
ALC. KOH
H
Q.3 C H 3 - C H 2 - C - C H = CH2 I CH3 (C6H12) Q.4 /R ,C = C
-H
l&Bansal Classes
HYDROCARBON
[39]
Me
Me "Br
+
CH 2 CH2
-H -Br
Q.5
BrHMe
BrMe
"H
Q.6
(E) CH, - C - CH
Br Q.7
OH
Q.8
C H 3 - C - C H - C H 3 ; ( Y ) C H 2 = C - C - C H 3 ; (Z) C H 3 - C = C - C H 3
CI
Q.10
(A)
<B>0 o
(B) CH 3 CH 2 COOK
(A)CH3-CH2-CH=CH-CH2-CH3
1 -> ozonolysis; 2 - LiAlH 4 ; 3 -> H 2 S 0 4 (4) HO-C1 ; (5) > CH 3 MgCl ; (6) -> t ^ O / f f
(1) NaN"H2, (2) Me-I, (3) H g S 0 4 dil H 2 S 0 4 higher electronegativity of sp carbon CH,
Q.21
(i) CH 3 - C - C H 2 - CH 3 O-C2H6
(ii) I
-CH,
CH,
Et
Q.23 Q.24
(X) Et-CsC-Et
(Y)->H>C=C<H
Et
Et
-OH
)^
-OH Et
Q.25
(a) CH 2 = C - CH = CH 2
O
(b)
(CH2
Q.26
( X ) I ^ J ,(Y) C H 3 - C - ( C H 2 ) 4 ~ C H = 0
CH,
l&Bansal Classes
HYDROCARBON
[40]
<1
BANSAL CLASSES CHEMISTRY
TARGET IIT JEE 2007
XI(PQRS)
llllllllllilllllilllll li|i|||||!ill||ll|||il||i;;:,
..,:|||lllllllllllllllll
IUPAC
Nomenclature according to IUPAC system involves use offollowing terms: (i) Word root: The word root represents the number of C atoms in parent chain. No. of C atom W.R. 1 Meth Octfe>8 2 Eth Non3Jps>9 3 Prop. DecaSe 10 4 But UndetoSBsll 5 Pent Doded&L12 6 Hex Tridecah13 7 Hep Primary suffix: Primary suffix is used to indicate saturation or unsaturation in carbon chain. While writing name, primary suffix is added to word root. Nature of C chain Primary suffix (1) Saturated C chain ane (2) Unsaturated C chain C=C ene C=C yne 2 C=C diyne Secondary suffix: Secondary suffix is used to indicate functional group in organic comp. It is added primary suffix by dropping its terminal "e".
(ii)
(iii)
Prefix: The part of the name C appears before the word root is called prefix. Different prefixes are used for dif categories of group as: (a) Alkyl groups: CH3-CH2-CH2 > 1-propyl CH3-CH-CH3 > 2-propyl CHj-CH^CHj-CT^ > 1-Butyl CH3-CH2-CH-CH3 > 2-Butyl CH, * 2-Methyl-l-propyl CH, - CH - CH, (b)
In IUPAC system,for nomenclature some groups are not considered as functional group but treated as substituent. These functional group are always indicated by prefixes instead of secondary suffixes. -N02 Mtro -OR Alkoxy -CI Chloro -Br Bromo -I Iodo -F Fluoro -N=0 Nitroso -N02 Nitro =N Diazo "[250]
tBansal Classes
(c)
In polyfunction^ compound, one ofthe functional group is treated as principal functional group & indicated by secondary suffix while other functional groups are treated as substituents & indicated by prefixes. O.Co. Alcohols Thioalcohols Amines Aldehyde Ketone carboxylic acid RCONH 2 RCOC1 RCOOR R-C=N Suffix ol thiol amine al one -oic acid amide ayl Kc^de. oate nitriie IUPAC Name alkanel alkanethiol alkanamii^o alkanal alkanone alkanoic acid alkanamide alkanoyi chloride alkylalkanoate alkanenitrile
, \ -rn, ^ . -
GF R-OH R-SH R-NH 2 R-CHO RCOR RCOOH Amides Acid chloride Ester Nitriles Arrangement:
Prefix Hydroxy Mercapto Amino formyl Keto or oxo Carboxy Carbamoyl Chloroformyl Carbalkoxy Cyano
Methyl but an ol
(i)
Rules: For saturated compounds: Selection of longest chain : (a) Longest continuous chain of carbon atoms is selected. This is called parent chain while all other C atoms C are not included in parent chain is called side chain.
<
C-C-C-C-C
c
->6
(b)
If more than one set oflongest chains are possible, the chain C max. no. of substituant acts as parent chain.
c-c-c-c-c-c
c-c
c
(ii)
Numbering of selected chain : (a) The selected chain is numberedfromone end to other. The number are called locants. Numbering is done in such a way that lowest no. is assigned to side chain or substituent get
< 7 %k < 5
C-C-C-C-C (b) CH, If two different alkyl groups or substituents are at same position from opposite ends, lowest no. is given in alphabetical order. * 2 & 4 & ^ c-C-C-C-C-C-C
-4 6 jS <-t 1
CH 3 faBansal Classes
NOMENCLATURE
(c)
If two different substituents are at same position from opp. ends, lowest no. is assigned in order of their alphabets.
c-c-c-c
CI I itvs H j o v v J ^ CO VL V r. a c 4Y6 W "VDOUU
S u t e S * ^
I I
c-c-c-c
CI Br
I I
If more than two substituents & side'chains are present, the sum oftheir numbers should be lowest at the first preference irrespective of the nature of substituent or side chain. This is K/a lowest sum rule.
7 6 5 4 3 2 1 1 2 3 4 5
Jvaue, ^ Series ^
CcwkiiHirfy
^
Z0
C-C-C-C-C C-C
"c%at
C H
C-C-C-C-C CI I CH,
3 y
locamts
CH, CH,
Br
.
Jre^rm-s exc^e- * In^asewheh starting loeant is lo^erfrom cfie sid, then lowest sum rule is n6t obeyed. Cotv^oW, -teawtyW,, t-b-C-d-C-C-C-t-t-C
Sashes sk.c&<ii4 | j j
VVO. CT 7\
1st
C C
(iii)
o c t e t s ;on. c^
Arrangement of prefixes : (a) Side chain or substituent group are added as prefix C its loeant in alphabetical order. CH3-CH-CH-CH, CI Br 2-bromo, 3-chlorobutane
If more than one similar alkyl group or substituents are present terms, tri like are used. CH 3 H,C C CH-, | CH 3
I
2,2-dimethyl propane
2;3-dimethyl
(c)
In case side chain is also branched, it is also numbered form carbon atom attached to main chain & is generally written in brackets. 3 4 5 6 7 CH, - CH 2 CH CH 2 CH 2 CH 2 CH 3 2 CH-CH3 1 CH 3
tBansal
Classes
NOMENCLATURE
OF ORGANIC
COMPOUND
1 CH-CH3 2 CH3
2-methyl-5-(l-methyI ethyl) octane The use ofiso & related common prefixes for describing alkyl group as long as these are not further substituted are also allowed by IUPAC nomenclature. While writing name in alphabetical order prefixes iso & neo are considered to be part of fundamental name of alkyl group. However sec. & tert are not considered to be part of fundamental name. CH3-CH-CH2CH3
c-c-d-c-c-c-c-c-c-c
-CP(CH3)# _ - - -
(i)
For unsaturated hydrocarbon: Select the longest possible carbon chain having maximum no. ofunsaturated carbon atoms or max. no. of double or triple bonds, even if puor rule is violated.
c-c-c-c-c-c Ifl i
c
- .
(ii)
Lowest no. is assigned tofirstunsaturated carbon even if prior rule is violated. 1 2 3 4 5 6 7 CH 3 - CH 2 - HC = CH - CH2 - C - i CH3 A CH, 3
(Si)
If double & triple bonds are at same position from either ends, lowest no is assigned to double bond 1 2
c=c-c-c=c
(iv)
If both alkene & alkyne group are present, the org. compound is named as derivative of alkyne rather than alkene. CH 3 -H=CH-C=CH Pent-3-en-l-yne In some cases all the double & triple bonds present in molecule can't be included in longest chain. In such cases following prefixes. CHJ = CH3-CH= Methylene Ethylidene CH=CEthynyl CH 2 =CHEthenyl
faBansal Classes
[5]
(i)
For functional groups : Select the longest possible carbon chain having max. no. offunctional even if prior rules are violated. C-C-C-C-C-OH I I
OH
c
(ii)
The carbon atom of functional group is to be included in deciding the longest carbon chain. C-C-CN 3 carbon chain C-C-C-CHO 4 carbon chain The lowest no is assigned to functional group even if prior rules are violated. O | 4 3 2
(lii)
CH3
5 4|
CH,
I
2 I
CH 3 -C-CH 2 -CH-CH 3
CI
1 The order ofnumbering a carbon chain, thus follows the order: (a) Functional group (b) Unsaturation (c) Substituents & side chains 7
(iv)
c=c-c-c-c-c-c
OH
1 I 2 3 4 5 6
5 4
3 2
c=c-c-c-c-c-c
OH
I
(v)
If more than 1 functional group; then choice ofprincipal functional group is made on the basis following order of preference: 0
I !
I I
I I
I I
I I
Carboxylic acid > S0 3 H > - C - O - C - > - C - O R > - C - 0 C 1 > > aldehyde > Ketone > alcohol > thiols > amines > ene > yne > halo > - O R
faBansal Classes
NOMENCLATURE
OF ORGANIC
COMPOUND
[6]
EXERCISE - I Q. 1 How many 10carbon atom will be present in a simplest hydrocarbon having two 3 and one 2 carbon atom? (A) 3 (B)4 (C)5 (D)6 C 3 H 6 Br 2 can shows: (A) Two gem dibromide (C) Two tert. dibromo alkane
Q.2
Q.3
The IUPAC name of the compound CH 3 CH = CHCH=CHC=CCH3 is: (A) 4,6-octadiene-2-yne (B) 2,4-octadiene-6-yne (C) 2-octyn-4,6-diene (D) 6-octyn-2,4-diene
5 1 t,
, ,
^QA)
The correct IUPAC name of the following compound is: O=CH-CH2-CH~CHO H~C = (A) 1,1 -diformyl propanal (C) 2-formyl butanedial (B) 3-formyl butanedial (D) 1,1,3-ethane tricarbaldehyde
Q5
All the following IUPAC names are correct except: (A) 1 -chloro-1 -ethoxy propane (B) 1 -amino-1 -ethoxypropane (C) l-ethoxy-2-propanol (D) 1-ethoxy-1-propanamine v O1 " J IUPAC name of: CH, - C - CH - C 3
(Wet ^ o V ^ ^ ^ ^ ^
Q.7
II
C=OO CH 3
II
(A) Methyl-2,2 acetyl ethanoate (C) Methyl-2-acetyl-3 -oxoc Q.8 The IUPAC name of j3-ethox, (A) 1,2-dihydroxy-l-oxo-3 (C) 3 -Ethoxy-2-hydroxy pro;
(B) 2,2 acetyl-1-methoxy ethanone (D) None ixy propionic acid (trivial name) is: , pane (B) 1 -carboxy-2-ethoxy ethanol (D) All above
faBansal
Classes
NOMENCLATURE
OF ORGANIC
COMPOUND
Q.9
The IUPAC name of compound C H 3 - C - C H - C H - C H - C H 3 is: I ! I CH 3 CHOCH 3 (A) 3,5-Dimethyl-4-Formyl pentanone (C) 2-Isopropyl-3 -methyl-4-oxo pentanal (B) 1 -Isopropyl-2-methyl-4-oxo butanal (D) None of the above
Q.10
HO - C = O CH 3 I I The IUPAC name of compound CH3 - C = C C - H is: I I NH 2 CI (A) 2-amino-3-chloro-2-methyl-2-pentenoic acid (B) 3-amino-4-chloro-2-methyl-2-pentenoic acid (C) 4-amino-3-chloro-2-methyl-2-pentenoic acid (D) All ofthe above
Q.LL
The IUPAC name ofthe structure is: CH-C] I I HOOC COOH (A) 3 -amino-2-formyl butane-1,4-dioic acid (C) 2-amino-3 -formyl butane-1,4-dioic acid (B) 3 -amino-2,3 -dicarboxy propanal (D) 1 -amino-2-formyl succinic acid
Q.12
C 4 H 6 0 2 does not represent: (A) A diketone (C) An alkenoic acid Esters arefiunctionalisomers of: (A) Hydroxy aldehyde (B) Ketone
(B) A compound with two aldehyde (D) An alkanoic acid (C) Diketone (D) Diols
Q .13
Q.14
How many carbons are in simplest alkyne having two side chains? (A) 5 (B)6 (C)7 Which ofthe following is not correctly matched: (A) Lactice acid CH3 - CH - COOH I OH HO-CH-COOH I HO-CH-COOH CH3C(CH3)2CHO CH, I 3 (D) Iso-octane I I CH 3 CH3 NOMENCLATURE
(D)8
Q.15
faBansal Classes
OF ORGANIC COMPOUND
[8]
Q.16 Which of the following pairs have absence of carbocyclic ring in both compounds? (A) Pyridine, Benzene (B) Benzene, Cyclohexane (C) Cyclohexane, Furane (D) Furane, Pyridine Q.17 The commerical name of trichloroethene is: (A) Westron (B)Perclene (C)Westrosol (D)Orlone
Q.18 The compound which has one isopropyl group is: (A) 2,2,3,3 -tetramethyl pentane (B) 2,2-dimethyl pentane (C) 2,2,3 -trimethyl pentane (D) 2-methyl pentane Q.19 How many secondary carbon atoms does methyl cyclopropane have? (A) None (B)One (C)Two (D) Three Q.20 The IUPAC name ofthe compound CH, - CH - CH is: I I I OH OH OH (A) 1,2,3-tri hydroxy propane (B) 3-hydroxy pentane-1,5-diol (C) 1,2,3-hydroxy propane (D) Propane-1,2,3-triol Q.21 As per IUPAC rules, which one of the following groups, will be regarded as the principal functional group? (A) -C=C(B)-OH (C) - C (D) - C - H I I I I o o Q. 22 Which of the following is thefirstmember of ester homologous series? (A) Ethyl ethanoate (B) Methyl ethanoate (C) Methyl methanoate (D) Ethyl methanoate Q.23 The correct IUPAC name of 2-ethyl-3-pentyne is: (A) 3 -methyl hexyne-4 (B) 4-ethyl pentyne-2 (C) 4-methyl hexyne-2 (D) None of these CI CH2CH3
Q.24 IUPAC name for the compound yC=C<^ is h3C/ \ (A) E-3 -iodo-4-chloro-3 -pentene (B) E-2-chloro-3 -iodo-2-pentene (C) Z-2-chloro-3 -iodo-2-pentene (D) Z-3-iodo-4-chloro-3 -pentene Ph Q.25 The IUPAC name ofthe compound is CH3 - CH - CH - NH2 I CH3 (A) 1 -amino-1 -phenyl-2-methyl propane (C) 2-methyl-1 -amino-1 -phenyl propane (B) 2-methyl-1 -phenyl propane-1 -amine (D) 1 -isopropyl-1 -phenyl methyl amine
tBansal Classes
"[9]
Hex-3-en-2-one 4-Methylpentanal
Q.29 The IUPAC name ofthe compound Br(Cl) CH. CF3 is: (A) haloethane (B) 1,1,1 -trifluoro-2-bromo-2-ch)oroethane (C) 2-bromo-2-chloro-1,1,1 -trifluoroethane (D) 1 -bromo-1 -chloro-2,2,2-trifloro ethane Q.30 The group ofhetrocylic compounds is: (A) Phenol, Furane (B) Furane, Thiophene (C) Thiophene, Phenol (D) Furane, Aniline Q. 31 The correct IUPAC name of CH , - CH2 - C - COOH is:
The IUPAC name ofthe following structure (CH3)C.C.C,(CH3)CH(CH3) is: (A) 3 -methyl-4-hexynene-2 (B) 3 -methyl-2-hexenyne-4 (C) 4-methyl-4-hexenyne-4 (D) all are correct
Q 33 The IUPAC name ofthe following structure is [CH3CH(CH3)]2 qCI^CH^QCH,) C(CH2CH3)2 (A) 3,5 -diethyl -4,6-dimethyl -5 -[ 1 -methylethyl]-3-heptene (B)3,5-diethyl-5-isopropyl-4,6-dimethyl-2-heptene (C) 3,5-diethyl-5-propyl-4,6-dimethyl-3-heptene (D) None of these faBansal Classes NOMENCLATURE OF ORGANIC COMPOUND JlOJ
q 34
c > @ '
c h 3
Number of secondary carbon atoms present in the above compounds are respectively: (A) 6,4,5 (B) 4,5,6 (C) 5,4,6 (D) 6,2,1 Q. 3 5 The IUPAC name of acetyl acetone is: (A) 2,5-Pentane dione (B) 2,4-Pentane dione (C) 2,4-Hexane dione (D) 2,4-butane dione Q. 3 6 When vinyl & allyl are joined each other, we get (A) Conjugated alkadiene (B) comulative alkadiene (C) Isolated alkadiene (D)Allenes Q.37 Glycerine is: (A) Propane triol-1,2,3 (C) Propyl glycol (B) Propylene trialcohol (D) Hydroxy methyl glycol
R^YCH2CLI,OH
and (b)l^J True statement for the above compounds is: (A) (a) is phenol while (b) is alcohol (B) Both (a) and (b) are primary alcohol (C) (a) is primary and (b) is secondary alcohol (D) (a) is secondary and (b) is primary alcohol Q.39 IUPAC name will be CH2 - CH - CH2 I ! ! CN CN CN (A) 1,2,3 -Tricyano propane (C) 1,2,3-cyano propane
0H
Q.40 A substance containing an equal number of primary, secondary and tertiary carbon atoms is: (A) Mesityl Oxide (B) Mesitylene (C) Maleic acid (D) Malonic acid
Q.41
IUPAC name of
or*
(B)Pent-2-ene-2,3-diol (D) Pent-3-ene-3,4-diol
tBansal Classes
"[11]
Q.43
Q.44
The IUPAC name of CH3 CH2 - N - CH2CH3 is: I CH3 (A) N-methyl-N-ethylethyl amine (C) N-ethyl-N-methyl ethyl amine (B) diethyl methyl amine (D) methyl diethyl amine
Q.45
The molecular formula of the first member of the family of alkenynes and its name is given by the set (A) C3H2, alkene (B) C5H6, l-penten-3-yne (C) C6Hg, l-hexen-5-yne (D) C4H4, butenyne 0 CH 2 -C-OH c < m The IUPAC name of compound | xCOOH CH2-COOH (A) 1,2,3 -tricarboxy-2,1 -propane (B) 3-Carbox-3-hydroxy-l,5-pentane dioic acid (C) 3 -hydroxy-3 -Carboxy-1,5-pentane dioic acid (D) None The IUPAC name of the compound: (A) Propylene Oxide (C) 1,2-Epoxy propane \ qi_ch 3 (B) 1,2-Oxo propane (D) 1,2-Propoxide
Q.46
Q.47
Q. 48
One among the following is the correct IUPAC name of the compound H I N (A) N-Formyl aminoethane (B) N-Ethyl formyl amine (C) N-Ethyl methanamide (D) Ethylamino methanal Which among the following is the correct IUPAC name of isoamylene: (A) 1 -Pentene (B) 2-Methyl-2-butene (C) 3 -Methyl-1 -butene (D) 2-Methyl-1 -butene
Q. 49
Q.50
<
|
S
OH is
CH3
HC = CH ^ I >S HC = CH /
(B)
HC = COOH I HC = COOH
(C)
HC = C H ^ HC = CH I >CH2(D) I HC = C H / HC = CH
C=0
faBansal Classes
NOMENCLATURE
OF ORGANIC COMPOUND
[12]
Q. 52 The number of primary, secondary and tertiary amines possible with the molecular fomula C3HgN is: (A) 1,2,2 (B) 1,2,1 (C) 2,1,1 (D) 3,0,1 Q. 53 The IUPAC name of C6H5CH=CH-COOHis: (A) cinnamic acid (B) 1 -phenyl-2-carboxy ethane (C) 3 -phenyl prop-2-enoic acid (D) dihydroxy-3 -phenyl propionic acid Q.54 The IUPAC name o f i ^ V CH = CH - CHCH2CH is:
U
c k
C - CH3 is: (B) methyl phenyl ketone (D) phenyl emethyl ketone CH3(CH2)4 Cll2 .C=C.
X
(CH2)7COOH ,C=C.
Q. 5 9 The suffix of the principal group, the prefixes for the other groups and the name of the parent in the structure
CH3
CI
(A) -oic acid, chloro, hydroxy, oxo, methyl, 4-heptene (B) -oic acid, chloro, hydroxy, methyl, oxo, 4-heptene (C) -one, carboxy, chloro. methyl, hydroxy, 4-heptene (D) -one, carboxy, chloro, methyl, hydroxy, 4-heptene faBansal Classes NOMENCLATURE OF ORGANIC COMPOUND JlOJ
Q. 60
The IUPAC name of compound COOH-CH-COOH I COOH (A) Tricarboxy methane (C) Tributanoic acid (B) Propane trioie acid (D) 2-carboxy propanedioic acid
Q. 61
CH, -CHO I 2 The IUPAC name of OHC - CH2 - CH2 - CH - CH2 - CHO is: (A) 4,4-di(formylmethyl) butanal (C) hexane-3-acetal-l, 6-dial (B) 2-(formylmethyl) butane-1,4-dicarbaldehyde (D) 3-(formyImethyl) hexane-1,6-diai
I]
^COCL
(A) 2-chlorocarbonyl ethylbenzoate (C) ethyl-2-(chlorocarbonyl) benzoate Q. 63 Which of the following is crotonic acid: (A) CH2= CH-COOH (C) CH,-CH=CH-COOH
The correct systematic name of the above compound is; (A) 2-acetoxy ethanoic acid (B) 2-methoxy carbonyl ethanoic acid (C) 3 -methoxy formyl ethanoic acid (D) 2-methoxy formyl acetic acid Q. 65 Structural formula ofisopropyl methanoate is: (A) C H , - C - O - C H - C H , I I I O CH3 (C) C H 3 - C - O - C H 2 - C H 2 I I I O CH3 Q. 66 The IUPAC name of
U
(A) I -cyclohexyl-3-methyl-1 -pentene (C) 1 -cyclohexyl-3 -ethyl-but-1 -ene Q.67 The correct IUPAC name ofthe compound: (A) 5-ethyl-3,6-dimethyl non-3-ene (C) 4-methyl-5,7-diethyl oct-2-ene Classes
tBansal
Q.12 Q.2
COOH
Q.13
Q.3
02N
Q.14
Q.4
Q.15
q.5
Q
6
Q.17
q.7
Q.18
Q.19
Q.8 OH CH2CH2CH2CH3
Q.10
Q.22
|^YC2h5
faBansal Classes
JlOJ
BivjCH,
Q.24
a
CH,
C-CH 3 CH,
CH3 O
^k.C-OCH
3
Q.35
CH3.CH.
Q.25
Q.36 CH2CH2CH=CH2
Q.26 Q.37
Q.27
Q.38
0<1
Q.28
C-CH2CH3
Q.39
Q.29
C-OC2H5
ff
Q.40
Q 32
A / C H O
c xBr
N
Q.44
-OH
OH Q.33
COOC2H5
faBansal Classes
[16]
Q.46
CH 3 (b) H 3 C - N - C H - C H 2 C H 3 CH 3 CjHJ
Q.47
Q.56
.-OH
Q.48
\CsCH
O CI
Q.49
r>
O \
K
Q.50
NH 2
Q.51
OC 2 H 5
Q.54
CH=CH-CH-CH=CH 2
Me
(a)
Me Me
Me = methyl group
faBansal Classes
NOMENCLATURE OF ORGANIC
COMPOUND
[17]
ANSWER KEY EXERCISE -1 Q.l Q.8 Q15 Q.22 Q.29 Q.36 Q.43 Q.50 Q.57 Q.64 B C D C D C D B A B Q2 Q.9 Q.16 Q.23 Q.30 Q.37 Q.44 Q.51 Q.58 Q.65 A C D C B A C A A D Q.3 Q.10 Q.17 Q.24 Q.31 Q.38 Q.45 Q.52 Q.59 Q.66 B B C C B D D C B A Q.4 Q.ll Q.18 Q.25 Q.32 Q.39 Q.46 Q.53 Q.60 Q.67 C C D B B A B C D A Q5 Q.12 Q.19 Q.26 Q.33 Q.40 Q.47 Q.54 Q.61 B D C B A B C A D Q.6 Q.13 Q.20 Q.27 Q.34 Q.41 Q.48 Q55 Q.62 B A D C A B C D C Q.7 Q.14 Q.21 Q.28 Q.35 Q.42 Q.49 Q.56 Q.63 C B D B B A C A C
1 -Hydroxy-3 -Butene-2-one
Q.2
CH3-CH2-CH-CH2-CH2-CH2
CH
3 Q.9
Q.4
iCN 2-Formyl pentane nitrile Q6 CH2 = CH - CH2 - OCH, 1 -Methoxy-2-prop ene Q.7 3 -methyl-1,4,6-Heptatriene NOMENCLATURE
Q.12
Q.13
Cyclopropanecarboxylic acid
faBansal Classes
OF ORGANIC
COMPOUND
[18]
Q.14 Cyclopropane carboxylic acid Q.15 Q.16 Q.17 1,3,5-cyclohexatriene 1,3-cyclobutadiene 1,2-epoxy propane
Q.39 spiro(4.5) decane Q 40 Bicyclo (2.2.1) heptane Q.41 Bicyclo(4.4.0) decane Q.42 Bicyclo(2.2.1) heptane Q.43 8-chloro bicyclo(4.2.0) oct-2-ene
Q.18 2,2,6,7-tetramethylocatane Q.19 3-ethyl-4,6-dimethyloctane Q. 20 Butyl cyclohexane Q.21 3 -isopropyl-1 -methylcyclohexane Q.22 2-ethyl-1 -methylcyclopentane Q.23 Methyl enyl cyclohexane Q.24 Isopylidenecyclopentane Q.25 Q.26 Q.27 Q.28 1,3,4-dimethyl-1 -cyclobutene 1 -(3 -butenyl) cyclopentene 1,2-diethenyl cyclohexene 1-cyclohexyl-l-propanone
Q.44 2-cyclepenten-l-ol Q.45 2-carbethoxy cyclopentanone Q.46 Bicyclo (3.1.0) hexane Q.47 Cyclohex-2-en-1,4-dione
Q.48 2-ethynyl cyclohexanol Q.49 4-chloro-1 -cyclopentyl pentane-2-one Q.50 Q. 51 1 -Amino methyl-2-ethyl cyclohexanol 1 -propyl-4-isopropyl-1 -cyclohexene
Q.32 6-Bromo-2-oxocyclohexanecarbaldehyde Q.33 3-amino-2-sec-butyl-5 -cyclohexen-1 -ol Q.34 2-bromo-2-methyl cyclopentanone Q.35 Methyl-2-methoxy-6-methyl-3- cyclohexene carboxylate Q.36 Bicylo(2.2. l)heptane Q.37 9-methyl bicyclo(4.2.1) nonane Q.38 spiro (2.5) octane tBansal Classes NOMENCLATURE OF ORGANIC COMPOUND ~ "[19]