STOICHIOMETRY_SOME BASIC CONCEPTS OF CHEMISTRY

PRACTICE QUESTIONS SHEET -1

EAMCET

1. Dissolving 120 g of a compound ( mol .wt = 60 ) in 1000 g of water gave a solution of

density 1.12 gmL1 . The molarity of solution is
1. 1.0 M 2. 2.0 M 3. 2.5 M 4. 4.0 M
2. To 50 ml of 0.1 N Na2CO3 solution 150 ml of water is added. What is the molarity of
resultant solution ?
M M M M
1. 2. 3. 4.
40 20 80 30
3. Calculate the molality of 1litre solution of 93% H2SO4 by w/v [ d H SO  1.84 g / cc ]
2 4

1.3.71 2.8.5 3.12.4 4.10.42

4. A litre of sea water (which weighs 1030 g) contains 6  10 3 g of dissolved oxygen. The
concentration of dissolved oxygen in ppm is
1. 5.8 2. 6.0 3. 6.2 4. 6.4
5. Hardness of water is 200 ppm. Calculate the molarity and normality of CaCO3 of the water.
1) 4  103 M ; 2  103 N 2) 2  106 M ; 4  103 N
3) 2  103 M ; 4  103 N 4) 1  103 M ; 4  103 N
6. Molarity of a 50 ml H 2 SO4 solution is 10.0 M. If the density of the solution is 1.4 gm/cc.
calculate its molality
1) 7.14 2) 8.00 3) 10.0 4) 0.500
7. 0.1 mol of NaCl is dissolved in 100 g of water. The mole fraction of NaCl is
1) 0.0213 2) 0.0177 3) 0.2290 4) 0.0330
8. What is the weight ( in g) of Na2CO3 (molar mass = 106) present in 250 mL of its 0.2 M
solution?
a) 0.53 b) 5.3 c) 1.06 d) 10.6
9. Commercially available H 2SO 4 is 98 gms by weight of H 2SO 4 and 2 gms by weight of
water. It's density is 1.83 g cm 3 . Calculate the molality (m) of H 2SO 4 (molar mass of H 2SO 4
is 98 g mol 1 )
a) 500 m b) 20 molal c) 50 m d) 200 m
10. The amount of iron (Fe) in g which can be produced from 600 g of magnetite ore is [Atomic
mass of Fe : 55.8]
1) 450 2) 379 3) 434 4) 210
JEE MAIN
11. What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining
21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by
hydrogen ?
A) 67.2 L B) 44.8 L C) 22.4 L D) 89.6 L
12. 25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric
acid have a titre value of 35 ml. The molarity of barium hydroxide solution was
A) 0.14 B) 0.28 C) 0.35 D) 0.07
13. Two solutions of a substance (non-electrolyte) are mixed in the following manner. 480 ml of
1.5 M first solution + 520 ml of 1.2 M second solution. What is the molarity of the final
mixture ?
A) 2.70 M B) 1.344 M C) 1.50 M D)1.20 M
-1
14. The density (in g mL ) of a 3.60 M sulphuric acid solution that is 29 % H2SO4 (molar mass
= 98 g mol-1) by mass will be
A) 1.45 B) 1.64 C) 1.88 D) 1.22
15. Consider the following reaction:
z
xMnO 4  yC 2 O 42  zH   xMn 2  2yCO 2  H 2 O
2
the value's of x, y and z in the reaction are, respectively
A) 5, 2 and 16 B) 2, 5 and 8 C) 2, 5 and 16 D)5, 2 and 8
16. 1 gram of a carbonate  M 2CO3  on treatment with excess HCl produces 0.01186 mole of
CO2 . The molar mass of M2CO3 in g mol1 is
A) 1186 B) 84.3 C) 118.6 D) 11.86
JEE ADVANCED
17. How many moles of electron weigh one kilogram ?
1 6.023 1
A) 6.023  10 23 B)  1031 C)  1054 D) 108
9.108 9.108 9.108  6.023
18. Which has maximum number of atoms ?
A) 24 g of C (12) B) 56 g of Fe (56) C) 27 g of Al (27) D) 108 g of Ag (108)
19. 2.76 g of silver carbonate is being strongly heated yields a residue weighing
A) 2.16 g B) 2.48 g C) 2.32 g D) 2.64 g
20. 1 mole of N2H4 loses10 moles of electrons to form a new compound Y. assuming that all
nitrogen appears in the new compound , what is the oxidation state of nitrogen in Y ?
[there is no change in the oxidation state of hydrogen.]
A) -1 B) -3 C) + 3 D) + 5
− 2− + 2+
21. For the redox reaction, MnO 4 + C2O 4 + H → Mn + CO2 + H2O
The correct coefficients of the reactants for the balanced reaction are
MnO4− C2O2−4 H+
A) 2 5 16
B) 16 5 2
C) 5 16 2
D) 2 16 5
22. The normality of 0.3 M phosphorous acid (H3 PO3) is
A) 0.1 B) 0.9 C) 0.3 D) 0.3
 ADDITIONAL QUESTIONS
23. Cyclohexanol is dehydrated to cyclohexene on heating with conc. H 2SO 4 . If the yield of this
reaction is 75%, how much cyclohexene will be obtained from 100 g of cyclohexanol ?
a) 61.5 g b) 82 g c) 109.3 g d) 75 g
24. When x g carbon is burnt with y g oxygen in a closed vessel, no residue is left behind.
Which of the following statement is correct regarding the relative amounts of oxygen and
carbon ?
a) y /x be less than 1.33 b) y / x must be greater than 1.33
c) y / x must be greater than 2.67 d) y / x must lie between 1.33 and 2.67
25. Equal weights of zinc metal and iodine are mixed together and the iodine is completely
converted to zinc iodide. What function of the original zinc remains unreacted ?
(Zn = 65.0)
a) 0.744 b) 0.256 g c) 0.5 d) 0.488
26. What weight of CO is required to form Re 2  CO 10 from 2.50 g of Re 2 O 7 according to the
unbalanced reaction : Re 2 O 7  CO  Re 2  CO 10  CO 2  Re  186.2 
a) 2.46 g b) 0.14 g c) 1.23 g d) 0.107 g
27. 11.2 g KOH is reacted with excess of Cl2 in hot condition. How many g of O2 will form by
complete decomposition of KClO3 formed ? The unbalanced reactions are
KOH  Cl 2  KCl  KClO 3  H 2O
KClO3  KCl  O 2
a) 0.8 g b) 8.0 g c) 6.4 g d) 1.6 g
28. 0.250 g of an element, M, reacts with excess fluorine to produce 0.547 g of the
hexafluoride, MF6 . What is the element? (Cr = 52, Mo = 95.94, S = 32, Te = 127.6)
a) Cr b) Mo c) S d) Te
29. A sample of iron ore, weighing 0.7 g, is dissolved in nitric acid. The solution is then
diluted with water, followed by addition of sufficient concentrated aqueous ammonia, to
quantitatively precipitate iron as Fe  OH 3 . The precipitate is filtered, ignited and weighed
as Fe 2O3 . If the weight of the ignited and dried precipitate is 0.541 g, what is the weight
percent of iron in the original iron ore sample ?
a) 27.0 % b) 48.1 % c) 54.1 % d) 81.1 %

KEY

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20
A D B D C B D A D C
21 22 23 24 25 26 27 28 29 30
A D A B A A B C