Entry Test Preparation 2015
Chemistry
Chapter # 7
CHEMICAL EQUILIBRIUM
Direction
You are given following questions
from the topic, with four choices A through D. Select the choice that will
answer the question best.
1. In the equilibrium
N2
+ 3H2 
2NH3 + 22
kcal the formation of ammonia is favoured by
2NH3 + 22
kcal the formation of ammonia is favoured by
A. Increasing the pressure B. Increasing
the temperature
C. Decreasing the pressure D. Adding
ammonia
2. In a reversible chemical reaction
having two reactants in equilibrium, if the concentration of the reactants are
doubled then the equilibrium constant will
A. Also be double B. Be
halved
C. Becomes the same D. Remains
the same
3. For the reaction
2A(g)
+ B(g) 3C(g) + D(g)
3C(g) + D(g)
two moles each
of A and B were taken into a flask. The following must always be true when the
system attained equilibrium
A. [A] = [B} B. [A]
< [B}
C. [B] = [C} D. [A]
> [B}
4. When pressure is applied to the equilibrium system Ice Water
Water
Which
of the following phenomenon will happen?
A. More ice will be formed B. Water
will evaporate
C. More water will be formed D. Equilibrium
will not be formed
5. Which of the following factors will
favour the reverse reaction in a chemical equilibrium?
A. Increase in concentration of one of the
reactants
B. Increase in concentration of one of the
products
C. Removal of one of the products regularly
D. None of these
6. The active mass of 64 g of HI in a two litre
flask would be
A. 2 B. 1
C. 5 D. 0.25
7. Two moles of HI was heated in a sealed
tube at 440oC till the equilibrium was reached. HI was found to be
22% decomposed. The equilibrium constant for dissociation is
A. 0.282 B. 0.0796
C. 0.0199 D. 1.99
8. In which of the following cases, the reaction goes farthest
to completion
A. K = 103 B. K = 10-2
C. K = 10 D. K = 100
9. The factor which changes equilibrium constant of the
reaction
A. Total pressure B. Amounts
of A2 and B2
C. Temperature D. Catalyst
10. At certain temperature, 50% of HI is
dissociated into H2 and I2 the equilibrium constant is
A. 1.0 B. 3.0
C. 0.5 D. 0.25
11. pH of water is
A. 0 B. 6
C. 14 D. 7
12. In a reaction A + B C + D, the initial
concentrations of A and B were 0.9 mol dm-3 each. At equilibrium the
concentration of D was found to be 0.6 mol dm-3. What is the value
of equilibrium constant for the reaction?
C + D, the initial
concentrations of A and B were 0.9 mol dm-3 each. At equilibrium the
concentration of D was found to be 0.6 mol dm-3. What is the value
of equilibrium constant for the reaction?
A. 8 B. 4
C. 9 D. 3
13. Kw=
A. Ka + Kb B. Ka / Kb
C. Ka x Kb D. Kp + Kc
14. A gas bulb is filled with NO2 gas and
immersed in an ice bath at 0oC which becomes colourless after
sometime. This colourless gas will be
A. NO2 B. N2O
C. N2O4 D. N2O5
15. In a lime kiln, to get higher yield of CO2, the
measure that can be taken is:
A. To maintain high temperature B. To
pump out CO2
C. To remove CaO D. To
add more CaCO3
16. Reactions that proceed on both sides and never go to
completion are called
A. irreversible B. reversible
reactions
C. opposing reactions D. spontaneous reactions
17. Chemical equilibrium involving reactants
and products in more than one phase is called
A. static B. dynamic
C. homogeneous D. heterogeneous
18. In a reversible reaction N2(g)
+ 3H2(g) 2NH3(g) if
the concentration of substances are in mole dm-3, then its Kc has
the unit
2NH3(g) if
the concentration of substances are in mole dm-3, then its Kc has
the unit
A. moles-2 dm+6 B. no units
C. mole dm-3 D. mole-1 dm-3
19. The relationship Kp and Kc for a gaseous
reaction is Kp = Kc (RT)
n.
n.
The
value of Kp and Kc are same when
A. reaction occurs at STP
B. reaction is exothermic
C. reaction is endothermic
D. number of moles of products and reactant
are same
20. The value of Kp is greater than Kc for a
gaseous reaction when
A. number of molecule of products is
greater than the reactants
B. number of molecules of reactant is
greater than those of products
C. number of molecules of reactants and
products equal
D. catalyst is added
21. An equeous solution is neutral when its
A. pH = 14 B. pH = zero
C. pH = 7 D. Kw = 10-7
22. An aqueous solution of H2SO4 is 10-3
mole dm-3, its pH is
A. 3.0 B. 2.0
C. 2.7 D. 1.5
23. A solution has pH = 0, its H+ ion concentration is
A. 1 x 10-14 B. 1 x 1014
C. 1 x 101 D. 1
24. A solution of NaOH has pH = 13, then concentration of NaOH is
A. 10-13 M B. 1013 M
C. 10-1 M D. 10+1 M
25. Acetic acid is 1.33% ionized. In 1000
molecules of 0.1 M acetic acid is dissociated
A. 1.33 B. 13.3
C. 1.33 D. 1
26. The solubility of KClO3 salt in water is decreased
by adding
A. NaClO3 B. NaCl
C. KClO4 D. KCl
27. 0.1 MHCl has pH = 1.0, it is about 100 times stronger than
acetic acid with pH.
A. 0.1 B. 2.0
C. 1.3 D. 3.0
28. A solution having pH = 4 its OH-
A. 
B. 
B.
C. 
D. 
D.
29. A solution having pOH = 6 its H+ ion concentration
in mole dm-3 is
A. 
B. 
B.
C. 
D. 
D.
30. pKa value of formic acid is 3.78 then pKb value of its format
ion is
A. 3.78 B. -3.78
C. 10.22 D. -10.22
31. pH of 1 molar NaOH is
A. 7 B. zero
C. 14 D. 10
32. pH of water is 7, if 0.01 M NaOH is added, than its pH is
A. 12 B. 14
C. zero D. 10
33. pH of 0.1 molar HCl solution is
A. 1 B. zero
C. 13 D. 14
34. pH of the human blood which is
essentially maintained constant due to carbonates, bicarbonates, phosphates
etc., is
A. 7.00 B. 7.25
C. 7.35 D. 7.47
35. pH of 0.1 molar CH3COOH when it is 1.3% ionized is
A. 2.89 B. 4.44
C. 4.74 D. 4.92
36. Le-Chatelier’s principle concluded that
A. The increase of temperature favours the
reaction which takes place with absorption of heat
B. The increase of pressure shift system in
the direction in which decrease in volume
C. A catalyst cannot effect the equilibrium
reaction
D. All of these
37. Which is the correct representation for
the solubility product constant of Ag2CrO4?
A. [Ag+]2[CrO4-2] B. [Ag+][CrO4-2]
C. [2Ag+][CrO4-2] D. [4Ag+][CrO4-2]
38. 2SO2(g) + O2(g) 
2SO3(g)-
the effect of adding catalyst in the above reaction is:
2SO3(g)-
the effect of adding catalyst in the above reaction is:
A. rate of forward reaction increased
B. rate of reverse reaction increased
C. more reactant is converted into product
D. A and B are correct
39. For the reaction, H2(g) + l2(g) 
2Hl(g) and Q = 
, A net reaction occurs in the forward direction, the
conditions are:
2Hl(g) and Q = , A net reaction occurs in the forward direction, the
conditions are:
A. Q < Kc B. Q > Kc
C. Q = Kc D. none of these
40. For the reaction, 2NO2(g) N2O4(g) + 61 KJ, increase of
temperature would:
N2O4(g) + 61 KJ, increase of
temperature would:
A. favours the formatin of N2O4 B. favours
the decomposition of N2O4
C. stop the reaction D. no
effect on equilibrium
41. Initial concentration of A, B and C are
1.0, 0.8 and 0.6 respectively, the equilibrium constant of A, B and C are:
A. same values
B. value of the Kc of A is greater than B
and C
C. Kc of C is greater than A and B
D. all of these
42. The relation between Kp and Kc is as follows:
A. KP = 
B. KP=Kc(RT)-1
B. KP=Kc(RT)-1
C. KP=Kc(RT)n D. all of these
n D. all of these
43. A reaction in which one or more reactants
is totally consumed, we say that a reaction goes to completion or very nearly
so, when:
A. Kc or KP is very small B. Kc or KP is very large
C. Kc is large and KP is small D. KP
is large and Kc is small
44. The law of chemical equilibrium is given by:
A. Le-Chatelier B. Guldberge & waage
C. Bohr’s D. Eintein
45. The solubility of BaSO4
(formula mass = 233) in water at 25oC is 0.000233 per 100ml of
solution, then the value of Ksp will be:
A. 
B. 
B.
C. D. 
D.
46. Which of the following is irreversible reaction:
A. N2+3H2
2NH3 B. PCl5 PCl3 + Cl2
2NH3 B. PCl5 PCl3 + Cl2
C. H2 + l2
2Hl D. NaCl + AgNO3 AgCl + NaNO3
2Hl D. NaCl + AgNO3 AgCl + NaNO3
47. Point out the incorrect statement in case of equilibrium
state:
A. It is dynamic in nature
B. It readjusts itself with the changing
conditions
C. It can be attained from the side of
reactants only D. It can be attained from either side
of the reaction
48. pH of milk is:
A. 6.5 B. 7.5
C. 8.5 D. 3.5
49. Which of the following relationship holds true in the
reaction, H2 + l2 2Hl.
2Hl.
A. Kp = Kc B. Kp > Kc
C. Kp < Kc D. non
of the above
50. Which of the following will change the value of Kc for the
reaction, H2 + l2 + heat
2Hl.
A. Change in pressure B. Change in temperature
C. Change in concentration D. By
adding catalyst
ANSWERS
CHEMICAL EQUILIBRIUM
1
|
A
|
2
|
D
|
3
|
B
|
4
|
C
|
5
|
B
|
6
|
D
|
7
|
C
|
8
|
A
|
9
|
C
|
10
|
D
|
11
|
D
|
12
|
B
|
13
|
C
|
14
|
C
|
15
|
B
|
16
|
B
|
17
|
D
|
18
|
A
|
19
|
D
|
20
|
A
|
21
|
C
|
22
|
C
|
23
|
D
|
24
|
C
|
25
|
B
|
26
|
D
|
27
|
D
|
28
|
B
|
29
|
A
|
30
|
C
|
31
|
C
|
32
|
A
|
33
|
A
|
34
|
C
|
35
|
A
|
36
|
D
|
37
|
A
|
38
|
D
|
39
|
A
|
40
|
B
|
41
|
A
|
42
|
D
|
43
|
B
|
44
|
B
|
45
|
C
|
46
|
D
|
47
|
C
|
48
|
A
|
49
|
A
|
50
|
B
|
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