No 1.

A reversible reaction is one which :

a) Proceeds in one direction
b) Proceeds in both directions
c) Proceeds spontaneously
d) All the statements are wrong
No 2. The equilibrium constant Kc for the reaction
P4(g) ↔ 2 P2(g)
o
is 1.4 at 400 C. Suppose that 3 moles of P4 (g) and 2 moles of P2(g) are
mixed in 2 litre container at 400oC. What is the value of reaction quotient
(QC)?
(a) 3/2 (b) 2/3 (c) 1 (d) None of these
No 3. In a chemical reaction equilibrium is established when :
a) Opposing reaction ceases
b) Concentrations of reactants and product are equal
c) Velocity of opposing reaction is the same as that of forward reaction
d) Reaction ceases to generate heat
No 4. The equilibrium constant for a reaction is K, and the reaction quotient
is Q. For a particular reaction mixture, the ratio K/Q is 0.33, This means that:
a) the reaction mixture will equilibrate to form more reactant species
b) the reaction mixture will equilibrate to form more product species
c) the equilibrium ratio of reactant to product concentrations will be 3
d) the equilibrium ratio of reactant to product concentrations will be 0.33
No 5. Consider the reaction 2SO2(g) + O2(g) ↔ 2SO3(g) for which Kc = 278 M-
1
. 0,001 mole of each of the reagents SO2(g), O2(g) and SO3(g) are mixed in a
1.0 L flask. Determine the reaction quotient of the system and the
spontaneous direction of the system :
a) Qc = 1000; the equilibrium shifts to the right
b) Qc = 1000; the equilibrium shifts to the left
c) Qc = 0,001; the equilibrium shifts to the left
d) Qc = 0.001; the equilibrium shifts to the right
No 6. In Q. No. 5, if the mixture of gases was allowed to come to
equilibrium. The volume of the reaction vessel was then rapidly increased
by a factor of two. As a result of the change the reaction quotient (Qt)
would:
a) increase because of the pressure decrease
b) decrease because of the pressure decrease
c) remain the same because the equilibrium constant is independent of
volume
d) increase because the reaction is endothermic
No 7. For the reaction A(g) + 3B(g) ↔ 2C(g) at 27oC, 2 moles of A, 4
moles of B and 6 moles of C are present in 2 litre vessel. If Kc for the
reaction is 1.2, the reaction will proceed in :
(a) forward direction (b) backward direction
(c) neither direction (d) none of these
No 8. For a reversible gaseous reaction N2 + 3H2 ↔ 2NH3 at equilibrium, if
some moles of H2 are replaced by same number of moles of T2 (T is tritium,
isotope of H and assume isotopes do not have different chemical properties)
without affecting other parameters, then :
a) The sample of ammonia obtained after sometime will be radioactive.
b) Moles of N2 after the change will be different as compared to moles of
N3 present before the change
c) The value of Kp or Kc will change
d) The average molecular mass of new equilibrium will be same as that
of old equilibrium
No 13. What is the unit of Kp for the reaction?
CS2(g) + 4H2(g) ↔ CH4(g)+2H2S(g)
(a) atm (b) atm-2 (c) atm2 (d) atm-
No 14. What is the unit of Kp for the reaction?
a) Kc = [02]5 (b) Kc = [P4O10]/ 5[P4][O2]
5
(c) Kc =[P4O10]/[P4][O2] (d) Kc = 1/[O2]5
15, At 5270C, the reaction given below has Kc =4

1 3
NH3(g) ↔ 2 N2 + 2 H2(g)
What is the Kp for the reaction?
N2 (g) + 3H2 (g) ↔ 2NH3 (g)
( ) ( )
−2 2
800 1
(a)16 x (800R)2 (b) (c) (d) None of these
4 4 × 800 R

16.The equilibrium constant for the reaction N2(g) + 02(g) ↔ 2NO(g) at

temperature (T) is 4 x 10-4. The value of Kc for the reaction NO(g) ↔
1 1
N (g)+ O 2 ( g ) at the same temperature is :
2 2 2

(a)4 x 10-4 (b) 50 (c)2.5 x l02 (d) 0.02

17. The equilibrium constant Kc for the following reaction at 842°C is 7.90
x 10-3, What is Kp at same temperature?
1
2
F(g) ↔ F(g)

8.64 x 10-5 (b) 8.26 x 10-4 (c) 7.90 x l0-2

(a) (d) 7.56 x l0-2
18, The equilibrium constant Kp for the following reaction at 191°C is 1.24.
What is Kc ?
3
B(s) + 2 F2(g) ↔ BF3(g)

(a) 6.7 (b) 0.61(c) .30 (d) 7.6

19. For the equilibrium SO2Cl2(g) ↔ SO2(g) + Cl2(g), what is the
P K (atm)
temperature at which k ( M ) =3 ?
c
 ,
(a) 0.027 K (b) 0.36 K (c) 36.54 K (d) 273 K

20, For the reversible reaction,

N2(g) + 3H2(g) ↔ NH3(g) .
-5
at 500°C, the value of Kp is 1.44 x 10 when partial pressure is measured
in atmospheres. The corresponding value of Kc with concentration in
mole litre-1, is:
(a) 1.44 x 10-5/(0.082 x 500)-2 (b) 1.44 x 10-5/(8.314 x 773)-2
(c) 1.44 x 10-5/(0.082 x 773)2 (d) 1.44x 10-5/(0.082x 773)-2
K
Kc
21. For the reaction CO(g) + Cl2(g) ↔ COCl2(g) the value of K is equal
P

to:

1
(a) √ RT (b) RT (c) RT (d) 1.0
22.The concentration of a pure solid or liquid phase is not included in the
expression of equilibrium constant because:
(a) solid and liquid concentrations are independent of
their quantities
(b) solids and liquids react slowly
(c) solids and liquids at equilibrium do not interact with
gaseous phase.
(d) the molecules of solids and liquids cannot migrate to the gaseous
phase.
23.A catalyst is a substance which :
(a) increases the equilibrium concentration of the product,
(b) changes the equilibrium constant of the reaction.
(c) shortens the time to reach equilibrium.
(d) supplies energy to the reaction.
24.What will be the effect on the equilibrium constant on increasing
temperature, if the reaction neither absorbs heat nor releases heat?
(a) Equilibrium constant will remain constant.
(b) Equilibrium constant will decrease.
(c) Equilibrium constant will increase.
(d) Can not be predicted
25.The equilibrium constant for the reaction N2(g) + 02(g) ↔ 2NO(g) is
4x10-4 at 200 K. In presence of a catalyst, equilibrium is attained ten
times faster. Therefore, the equilibrium constant in presence of the
catalyst at 200 K is ;
(a) 40 x 10-4 (b) 4 x l0-4
(c) 4 x 10 -3 (d) difficult to compute without more
data
26.For the reaction H2(g) + I2(g) ↔ 2HI(g), the equilibrium constant
changes with:
28. For the reaction 2N02(g) + - 02(g) ^ N 20s (g), if the equilibrium constant is K pi then
the
(a) total pressure (b) catalyst(c) concentration of H2
and I2 (d) temperature

27.Consider the reactions

(i) 2CO(g) + 2H2O(g) ↔ 2CO2(g) + 2H2(g); Eqm. Constant =K1

(ii) CH4(g) + H2O(g) ↔ CO(g) + 3H2(g); Eqm. Constant = K2

(iii) CH4(g) + 2H2O(g) ↔ CO2(g) + 4H2(g); Eqm. Constant = K3

Which of the following relation is correct?

2
K1 K1
(a) K 3= K2
(b) K 3= 2
K2

(c) K1.K2 (d) K 3= √ K 1 K 2

28. For the reaction 2N02(g) + - 02(g) ^ N 20s (g), if the equilibrium constant is K pi then
the

equilibrium constant for the reaction 2N205 (g) ↔ 4N02(g) + 02(g) would be

2 1 1
(a) K2p (b) K (c) K 2 (d)
p p √ Kp
29. The equilibrium constant (Kc) for the reaction
2HCl(g) ↔ H2(g) + Cl2(g)
-34 o
is 4 x 10 at 25 C. What is the equilibrium constant for the reaction?
1 1
2
H2(g) + Cl2(g) ↔ HCl(g)
2

(a) 2 x 10-17 ’ (b) 2.5 x 1033 (c) 5 x l06 (d) None of these
30. At a certain temperature, the following reactions have the equilibrium
constants as showing below: ..
52
S(s) + 02(g) ↔ SO2(g); Kc = 5 x 10
2S(s) + 302(g) ↔ 2SO3(g); Kc = 1029 :
What is the equilibrium constant Kc for the reaction at the same
temperature ?
2S02(g) + O2(g) ↔ 2SO3(g)

(a) 2,5 x 1076 (b) 4x1023 (e) 4 x 10-77 (d) None of these

32. In the reaction X(g) + Y(g) ↔ 2Z(g), 2 mole of X, 1 mole of Y and 1

mole of Z are placed in a 10 litre vessel and allowed to reach
equilibrium. If final concentration of Z is 0,2 M, then Kc for the given
reaction is : .
80 16
(a) 1.60 (b) 3 (c) 3 (d) None of these
35* The equilibrium constant for the following reaction is 10.5 at 500 K. A
system at equilibrium has [CO] = 0.250 M and [H2] = 0.120 M. What is
the [CH3OH]?
CO(g) + 2H2(g) ↔ CH3OH(g)
(a) 0,0378 (b) 0.0435 (c) 0,546 (d) 0.0499
36. When sulphur (in the form of S8) is heated at temperature T,at
equilibrium, the pressure of SB falls by 30% from 1.0 atm, because Sa(g)
is partially converted into S2(g).
Find the value of Kp for this reaction.
(a) 2,96 (b) 6.14 (c) 204.8 (d) None of these
37. 9,2 grams of N2O4(g) is taken in a dosed one litre vessel and heated till the
following equilibrium is reached N204 (g) ↔ 2NO2(g)
At equilibrium, 50% N2O4(g) is dissociated. What is the equilibrium
constant (in mol litre -1) (molecular weight of N204 = 92)
(a) 0.1 ‘ (b) 0-4 (c) 0.2 (d) 2
38. Two moles of NH3 when put into a previously evacuated vessel (one
litre), partially dissociated into N2 and H2, If at equilibrium one mole of
NH3 is present, the equilibrium constant is :
(a) 3/4 mol2litre2
(b) 27/64 mol2litre-2
(c) 27/32 mol2litre-2
(d) 27/16 mol2Iitre-2
39. In the presence of excess of anhydrous SrCl2, the amount of water taken
up is governed by Kp = 1012 atm-4 for the following reaction at 273 K
SrCl2 . 2H2O(S) + 4H2O(g) ↔ SrCl2 . 6H2O(s)
What is equilibrium vapour pressure (in torr) of water in a closed vessel
that contains SrCl2 . 2H2O(S)? ,
(a) 0.001 torr (b) 103 torr (c) 0,76 torr (d) 1.31 torr
40. CuSO4 . 5H2O(s) ↔ CuS04 . 3H20(s) + 2H2O(g); Kp = 4 x 10-4 atm2. If the
vapour pressure of water is 38 torr then percentage of relative humidity
is: (Assume all data at constant temperature) -
(a) 4 (b) 10 (c) 40 (d) None of these
41. NH4HS(S) ↔ NH3(g) + H2S(g)
The equilibrium pressure at 25oC is 0.660 atm. What is Kp for the
reaction?
(a) 0,109 (b) 0.218 (c) 1.89 (d) 2.18
42.
For the reaction 2A(g) ↔ B(g) + 3C(g), at a given temperature, Kc = 16.
What must be the volume of the flask, if a mixture of 2 mole each of A,B and
C exist in equilibrium?

1 1
(a) 4 (b) 2 (c) 1 (d) None of these
43. One mole of pure ethyl ancol was treated with one mole of pure acetic
acid at 25oC. One-third of the acid changes into ester at equilibrium. The
equilibrium constant for the reaction will be:
 1
(a) 4 (b) 2 (c) 3 (d) 4
44. I2 (aq) + I-(aq) ↔ I-3 (aq). We started with 1 mole of I2 and 0.5 mole of I- in
one litre flask. After equilibirium is reached, excess of AgNO3 gave 0.25 mole
of yellow precipitate. Equilibirium constant is:
(a) 1.33 (b) 2.66 (c) 2.0 (d) 3.0
45. At 87°C, the following equilibrium is established.

H2(g) + S(s) ↔ H2S(g); Kc = 0.08

If 0.3 mole hydrogen and 2 mole sulphur are heated to 87oC in a 2 L
vessel, what will be the concentration of H2S at equilibrium?
(a) 0.011 M (b) 0.022 M (c) 0.044 Af (d) 0.08 M *
46. In the equilibrium 2SO2(g) + 02(g) ↔2SO3(g), the partial pressure of S02,
O2 and SO3 are 0.662, 0.10 and 0.331 atm respectively What should be the
partial pressure of oxygen so that the equilibrium concentrations of SO2 and
SO3 are equal?
(a) 0.4 atm (b) 1.0 atm (c) 0.8 atm (d) 0.25 atm
47. When heated, ammonium carbamate decomposes as follows :

NH4COONH2(S) ↔ 2NH3(g) + C02(g)

At a certain temperature, the equilibrium pressure of the system is
0.318 atm. Kp for the reaction is:
(a) 0.128 (b) 0.426 (c) 4.76 x 10-3 (d) None of these
48. In a system A(s) ↔ 2B(g) + 3C(g), if the concentration of C at
equilibrium is increased by a factor of 2, it will cause the
equilibrium concentration of B to change to :
(a) two times the original value (b) one half of its original value
1
(c) 2 √ 2 times to the original value (d) times the original value
2 √2
49. A + B ↔ C + D. If finally the concentration of A and B are both equal but
at equilibrium concentration of D will be twice of that of A then what
will be the equilibrium constant of reaction?
4 9 1
(a) 9 (b) 4 (c) 9 (d) 4
50. The equilibrium constant Kc for the reaction S02(g) + NO2(g) ↔ SO3(g) +
NO(g) is 16. If 1 mole of each of all the four gases is taken in 1 dm3
vessel, the equilibrium concentration of NO would be :
(a) 0.4 M (b) 0.6 M (c) 1.4 M (d) 1.6 M

51. On increasing the temperature, the rare of a reaction :

(a) always increases
(b) always decreases
(c) first increases then decreases
(d) may increases or decreases depending upon the nature of the reaction
52. A catalyst increases the rate of a reaction by :
(a) increasing the activation energy of the reaction
(b) increasing the value of rate constants (kf and kb)
(c) increasing the enthalpy change of the reaction
 (d)decreasing the enthalpy change of the reaction

53. At a certain temperature, only 50% HI is dissociated at equilibrium in the

following reaction;
2HI(g) ↔ H2(g) + I2(g)
The equilibrium constant for this reaction is :
(a) 0.25 (b) 1.0 (c) 3.0 (d) 0.5
54. The equilibrium constant Kp for the reaction
H2(g)+C02(g) ↔ H2O(g) + CO(g)
is 4.0 at 1660°C. Initially 0.80 mole H2 and 0.80 mole CO2 are injected
into a 5.0 litre flask. What is the equilibrium concentration of CO2(g) ?
(a) 0.533 M (b) 0.0534 M (c) 0.535 M (d) None of these
55. At 273 K and 1 atm, 10 litre of N204 decomposes to NO2 according to
equation
N2O4(g) ↔ 2NO2(g
What is degree of dissociation (α) when the original volume is 25% less
than that of existing volume?
(a) 0.25 (b) 0.33 (c) 0.66 (d) 0.5
56. The equilibrium constant for the reaction CO(g) + H2O(g) ↔CO2(g) +
H2(g) is 5. How many moles of CO2 must be added to 1 litre container
already containing 3 moles each of CO and H2O to make 2M equilibrium
concentration of CO?
(a) 15 (b) 19 (c) 5 (d) 20
57. A nitrogen-hydrogen mixture initially in the molar ratio of 1:3
reached equilibrium to form ammonia when 25% of the N2 and H2 had
reacted. If the total pressure of the system was 21 atm, the partial pressure
of ammonia at the equilibrium was : -
(a) 4.5 atm (b) 3.0 atm (c) 2,0 atm (d) 1.5 atm
53, Ammonia under a pressure of 15 atm at 27°C is heated to 347°C in a
closed vessel in the presence of a catalyst. Under the conditions, NH3 is
partially decomposed according to the equation,
2NH3↔ N2 + 3H2 the vessel is such that the volume remains effectively
constant where as pressure increases to 50 atm. Calculate the percentage
of NH3 actually decomposed :
(a) 65% (b) 61.3% (c) 62.5% (d) 64%
59. 0.l mole of N204(g) was sealed in a tube under one atmospheric conditions at 25°C.
Calculate the number of moles of N02(g) present, if the equilibrium N204(g) ↔
2N02(g) (Kp = 0.14) is reached after some time
(a) 1.8x 103 (b) 2.8 x102 (c) 0,034 (d) 2.8x 10-2
60. 5 moles of SO2 and 5 moles of O2 are allowed to react. At equilibrium, it was
found that 60% of SO2 is used up. If the pressure of the equilibrium mixture is one
atmosphere, the partial pressure of O2 is:
(a) 0.52 atm (b) 0.21 atm (c) 0.41 atm (d) 0.82 atm
61, N2(g) + 3H2(g) ↔ 2NH3(g)
For the reaction initially the mole ratio was 1:3 of N2 : H2. At equilibrium 50% of
each has reacted. If the equilibrium pressure is P, the partial pressure of NH3 at
equilibrium is:

P P P P
(a) 3 (b) 4 (c) 6 (d) 8

62. 2.0 mole of PCI 5 were introduced in a vessel of 5,0 L capacity of a

particular temperature. At equilibrium, PC15 was found to be 35% dissociated
into PC13 and Cl2. The value of Kc for the reaction
PCI3(g)+Cl2(g) ↔ PCl5(g)
(a) 1.89 (b) 0.377 (c) 1.33 (d) 13.3
63. At certain temperature compound AB2(g) dissociates according to the
reaction
 2AB2(g) ↔ 2AB(g) + B2(g)
With degree of dissociation α, which is small compared with unity. The
expresion of Kp in terms of α and initial pressure P is:
3 2 3 2
α Pα α Pα
(a) P (b) (c) P (d)
2 3 3 2
64. For the reaction
H2(g) + CO2(g) ↔ CO(g) + H20(g). If the initial concentration of
[H2]=[CO2] and x moles/litre of hydrogen is consumed at equilibrium, the
correct expression of Kp is:
67* At 27oC and 1 atm pressure, N2O4 is 20% dissociation into NO2 .What is
the density of equilibrium mixture of N2O4 and NO2 at 27oC and 1 atm?
(a) 3.11 g/litre (b) 2.11 g/litre (c) 4.5 g/litre (d) None of these
68* COCl2 gas dissociates according to the equation, COCl2(g) ↔ CO(g) +
Cl2(g). When heated to 700 K the density of the gas mixture at 1.16 atm
and at equilibrium is 1.16 g/litre. The degree of dissociation of CO2 at
700K is:
(a) 0.28 (b) 0.50 (c) 0.72 (d) 0.42
69* The degree of dissociation of I2 molecule of 1000°C and under
atmospheric pressure is 40% by volume. If the dissociation is reduced
to 20% at the same temp, total equilibrium pressure on the gas is :
(a) 1.57atm (b) 2,57atm (c) 3.57 atm (d) 4.57atm
70. Determine the value of equilibrium constant (Kc) for the reaction

A2(g) + B2(g) -> 2AB(g)

If 10 moles of A2; 15 moles of B2 and 5 moles of AB are placed in a 2
litre vessel and allowed to come to equilibrium. The final concentration of
AB is 7.5 M:
(a) 4.5 , (b) 1.5 (c) 0.6 (d) None of these
71. At 87°C, the following equilibrium is established

H2(g) + S(s) ↔ H2S(g); Kp =7 x l0-2

If 0.50 mole of hydrogen and 1.0 mole of sulphur are heated to 87oC in
1.0 L vessel, what will be the partial pressure of H2S at equilibrium?
‘ (a) 0.966 atm (b) 1.38 atm (c) 0.0327 atm (d) 1 atm
72. Pure PCl5 is introduced into an evacuated chamber and comes to
equilibrium at 247oC and 2.0 atm. The equilibrium gaseous mixture
contains 40% chlorine by volume.
Calculate Kp at 247°C for the reaction
PCl5(g) ↔ PCl3(g) + Cl2(g)
(a) 0.625 atm (b) 4 atm (c) 1.6 atm (d) None of these
73. For the reaction
SnO2(s)+2H2(g) ↔ 2H2O(g) + Sn(l)
calculate Kp at 900 K, where the equilibrium steam-hydrogen mixture
was 45% H2 by volume :
(a) 1.49 (b) 1.22 (c) 0.67 (d) None of these
74. For the reaction XCO3(s) ↔ XO(s) + CO2(g), Kp =1.642 atm at 727°C. If
4 moles of XCO3(s) was put into a 50 litre container and heated to 727QC.
What mole percent of the XCO3 remains unreacted at equilibrium?
(a) 20 (b) 25 (c) 50 (d) None of these
75. Fe203(s) may be converted to Fe by the reaction
Fe2O3(s)+3H2(g) ↔ 2Fe(s) + 3H2O(g),
for which Kc = 8 at temp. 720CC.
What percentage of the H2 remains unreacted after the reaction has come
to equilibrium?
 (a) ≈22% (b) ≈ 34% (c) ≈ 66% (d) ≈ 78%
1
76. AB3(g) is dissociates as AB3(g) ↔ AB2(g) + 2 B2(g).

When the initial pressure of AB2 is 800 torr and the total pressure
developed at equilibrium is 900 torr. What fraction of AB3(g) is
dissociated?
(a) 10% (b) 20% (c) 25% (d) 30%
77. At 1000 K, a sample of pure N02 gas decomposes as ;
2N02(g) ↔ 2NO(g) + O2(g)
The equilibrium constant Kp is 156.25 atm. Analysis shows that the
partial pressure of O2 is 0.25 atm at equilibrium. The partial pressure of
NOa at equilibrium is :
(a) 0.01 (b) 0.02 (c) 0.04 (d) None of these
78. Pure nitrosyl chloride (NOC1) gas was heated to 240°C in a 1.0 L
container. At equilibrium the total
pressure was 1.0 atm and the NOCl pressure was 0.64 atm. What would
be die value of Kp?
(a) 1.02 atm fb) 16.875 * 10“3 atm
(c) 16 x 10 2 atm fd) None of these
79, At a certain temperature the equilibrium constant Kc is 0.25 for the
reaction
A2(g) + B2(g) C2(g) + £>2(g)
If we take 1 mole of each of the four gases in a 10 litre container, what
would be equilibrium concentration of A2(g)?
(a) 0.331 M (b) 0.033 M (O 0.133 M (d) 1.33 M
50. At 200°C PCIs dissociates as follows :
pci5fe) ^ pci3cgi + aatg) -
It was found that the equilibrium vapours are 62 times as heavy as
hydrogen. The degree of dissociation of Pd5 at 200°C is nearly ; .
(a) 10% (b) 42% (cl 50% (d) 68%
51. For the dissociation reaction N204 (g) 2N02(g), the degree of
dissociation (a) in terms
of K and total equilibrium pressure P is :
la)a
-J^iF (DNoneofth^
82.
The graph which represents all the equilibrium concentrations for the
reaction
N204fg)^2N02tg)
Then the select the correct graph for concentrations of NQ2 against
concentrations of N04:

(c)
(a) 1?

[M2041 [M20s) (NA] [N2Oj

■
82. The vapour pressure of mercury is 0.002 mm Hg at 27°C. K. for the process Hg(l) - Hg(g)
is :
(a) 0.002 fb) 8.12xio s (c) 6.48 xlO-5 (d) 1.068 x 1(T7
Calculate the equilibrium constant (ifc) for the reaction below if they are present at equilibrium
84. 5,0 mole of A2, 3 mole of B2 and 2 mole of AB2 at 8.21 atm and 300 K
A2(g) + 2B2(g) ** 2AB2(g) +■ Heat
(al 1.333 fb) 2.66 (cl 20 (dl None of these

Ti
Given the following reaction at equilibrium, N2(g) + 3H2(g)2NH3(g).
Some inert gas
at constant pressure is added to the system. Predict which of the following
facts will be affected? '
(a) More NHa(g) is produced (b) Less NH3(g) is produced
(c) No affect on the equilibrium (d) K„ of the reaction is decreased
87. Change in volume of the system does not alter the number of moles in
which of the following equilibrium :
(a) N2Cg) + 02(g)^ 2NO(g) (bl PCls(g)^ PCl3Cg) + Cl2(g)
; Cc) N2Cg)+3H2(g]^2NH3Cg> Cd) S02Cl2Cgl^S02(g)-s-Clz(g)
88, For the reaction
_ N2Cgl + 3H2Cgl 2NH3CE); AH =-93.6 kJ mol-1
' ‘ the number of moles of H2 at equilibrium will increase if :
. ■ Ca) volume is increased (b) volume is decreased
(cl argon gas is added at constant volume (d) NH3 is removed
89. The volume of the reaction vessel containing an equilibrium mixture is
increased in the following reaction
S03Cl2Cg) ^ S02(g)+Cl2(g)
When equilibrium is re-established :
(a) the amount of Cl2(g) remains unchanged
(b) the amount of CI2(g) increases
to) the amount of S02Cl2(g)
increases (d) the amount of
SO2 (g) decreases
90. Some inert gas is added at constant volume to the following reaction at
equilibrium
NH4HS(S) ^ NH3(g) + H2S(g)
Predict the effect of adding the inert gas :
(a) the equilibrium shifts in the forward direction
(b) the equilibrium shifts in the backward direction
(c) the equilibrium remains unaffected
(d) the value of Kp is increased

91 Consider the reaction where Kp = 0.497 at 500 K

PCl,(g)^PCl3(g) + Cl2(g)
If the three gases are mixed in a rigid container so that the partial pressure
of each gas in initially 1 atm. Which is true ?
(a) More PCl5 will be produced
(b) More PC13 will be produced
(c) Equilibrium will be established when 50% reaction is complete
(d) None of the above

94. In a vessel containing N2, H2 and NH3 at equilibrium, some helium gas is
introduced so that
total pressure increase while temperature and volume remain constant.
According to Le Chateiier’s principle, the dissociation of NH3 i
(a) increases (b)decreases
(c) remains unaltered (d)changes unpredictably
95. Le-Chatelier principle is not applicable to :
(a) H2(g) + I2(g) ^ 2HI(g) (b) rFefs) + S(s) ^ FeS(s)
(c) N2(g)+3H2{£)^2NH3(g) (d)N2Cg) + 02Cg)^2N0(g)

96. Consider the following reactions. In which cases is the product formation
favoured by decreased pressure?
(1) C02fg) + C00 ^ 2CO(g); AH° = + 372,5 kJ
(2) N2(g)-s-3H2(g)=F* 2NH3(g); AW° = - 9 1 8 k J
a
(3) Nafg) + 02(g) ^ 2NO(g); AH = 181 kJ
0
(4) 2H20fg) ^ 2H2(g) + 0a(g); AH = 484.6 kJ
(a) 2, 3 (b) 3, 4 (c) 2, 4 (d) 1, 4
97. Consider the following reactions. In which cases is product formation
favoured by decreased temperature?
(1) N2(g) + 02(g) 2NO(g);
(2) 2COzfgl ^ 2CO(g) + 02(g);
Aff“ = 181
(3) H2(g) + I2(g) ^ 2Hl(g);
kJ AHC =
(4) H2(g) + Fa(g) ^ 2HFfg]; 566 kJ AH°
(a) 1, 2 (b) 2 only = — 9.4 kJ
= - 541 kJ
CO 1, 2, 3 (d) 3, 4
98. For which of the following reactions is product formation favoured by
low pressure and high
temperature?
(a) H (g) + 1 (g) ^ 2111(g);
2 2
AH° = -9.4
(b) C0 (g) + C(s) ^ 2CO(g);
2
kJ AH'3 =
(c) CO (g) + 2H (g) ^ CH OH;
172.5 kJ
2 3

5 (d) 30 (g) ^ 20 [g);

2 3
AH = - 21.7 kJ
AH” = 285 kJ ■
99. For which of the following reaction is product formation favoured by low
pressure and low temperature?
(a) CO (g) + C(s) ^ 2CO(g); 0
a
AH =
(b) CO(g) + 2H (g) ^ CH OH;
2 3
172.5 kJ
(c) 20 (g) ^ 30 (g);
AFP--21.7
3 2

(d) H (g) + F (g) ^ 211 F(g);

2 2
kJ AFP =
— 285 kJ AFP = -541 kJ
101. If the pressure in a reaction vessel for the following reaction is increased
by decreasing the volume, what will happen to the concentrations of CO
and C02?
H20(g) + CO(g) H2(g) a C02tg) + Heat
(a) both the [CO] and [C02] will decrease '
(b) neither the [CO] nor the [C02] will change
(c) the [CO] will decrease and the [C02] will increase
(d) both the [CO] and [C02] will increase

102. Consider the following reaction and determine which of the conditions
will shift the equilibrium position to the right?
4NH3(g}+ 502fc) 4NOfe) + 6H20(g) + Hear
(a) increasing the temperature (b) increasing the pressure
(c) adding a catalyst (d) none of the above is correct
103. The conversion of ozone into oxygen is exothermic. Under what
conditions is ozone the most stable?
■ 203(g) ^ 302(g)
(a) At low pressure and low temperature (b) At high pressure and
high temperature
(c) At high pressure and low temperature (d) At low pressure and
high temperature
104. A system at equilibrium is described by the equation of fixed
temperature T.
S02Cl2(g) -- S02(g) + Cl2(g)
What effect will an increases in the total pressure caused by a decrease
in volume have on the equilibrium? .
(a) Concentration of SO2Cl 2(g) increases (b) Concentration of
S03C?) increases
(c) Concentration of CI2(g) increases(d) Concentration of all gases
increases
105. The reaction 2NG2(g) ^ N204 (g) is an exothermic equilibrium. This
means that:
(a) equilibration of thjs gas mixture will be slower at high temperature
(b) a mole of N204 will occupy twice the volume of a mole of N0 2 at the
same
(c) the.equilibrium will move to the right if an equilibrium mixture is
cooled
(d) the position of equilibrium will move to the left with increasing gas
pressure
106. Densities of diamond and graphite are 3.5 and
2.3 gm/mL C (diamond) ^ C (graphite); ArH --
1.9kJ/mol favourable conditions for formation
of graphite are :
(a) high pressure and low temperature(b)low pressure and high
temperature
(c) high pressure and high temperature (d) low pressure and low
temperature
107. For an equilibrium H20(s) =t=^ H20(i), which of the following statements
is true?
(a) The pressure changes do not affect the equilibrium
(b) More of ice melts if pressure on the system is increased
(c) More of liquid freezes if pressure on the system is increased
(d) The pressure changes may increase or decrease the degree of
advancement of the process
108. A pressure cooker reduces cooking time for food because:
fa) the higher pressure inside the cooker crushes the food material
fb) cooking involves chemical changes helped by a rise
in temperature (c) heat is more evenly distributed in the
cooking space
fd> boiling point of water involved in cooking is increased
109- The vapour pressure of a liquid in a dosed container depends on ;
(1) temperature of liquid
(2) quantity of liquid
(3) surface area of the liquid
(a) 1 only (b) 2 only (c) 1 and 3 only (d) 1, 2 and
3
110. The pressure on a sample of water at its triple pointis reduced while the
temperature is held
constant. Which phases changes are favoured?

(I) melting of icc

(ID sublimation of ice
(III) vaporization of liquid water
(a) I only (b) III only (c) II only (d)H and IIT
111. An exothermic reaction is represented by the graph ;
114. What is the correct relationship between free energy change and
equilibrium constant of a reaction :

(a) AG° = RT In K (b) AG° = - RT In K

(c) AC = RT In K (d) AG = -RT In K
115. For the chemical equilibrium CaC03(s) ^ CaO(s) 4 C03(g), AHr° can be
determined from which one of the following plots ?

116. Kp has the value of 10 6 atm3 and 10 4 atm3 at 298 K and 323 K
respectively far the reaction
. CuS04-3H20(S) CUS04(S)4 3H20(g)
ArHsfor the reaction is : ' .
(a). 7.7 kJ/mol (b) -147.41 kJ/mol
(c) 147,41 kJ/mol (d). None of these
117, van’t Hoffs equation shows the effect of temperature on equilibrium
K P2 AH' fb) log t>2
AH° T 2 -T I
(a) log
Kp. 2.303 R{ T X T 2 K 2.303 R { T X T 2
P
i
 constants Kc and Kp. The Kp varies with temperature according to the
relation :
118. For a reaction, the value offfp increases with increase in temperature. The
A H for the reaction would be :
(a) positive (b) negative
(c) zero (d) cannot be predicted
119. The most stable oxides of nitrogen
CAU will be ;
KHO 16
(a) 2NO2(g) ^ Na(g) + 202(g); K = 6.7 x 10 mol L
_1
24 5 -5
(b) 2N205(g) ^ 2N2(g) + 502(g); .K = 1.2 x 10 mol L
30
(c) 2N0(g) ^ N2Cs) + 02Cg); Jf = 2.2xl0
33 _1
(d) 2N20(g) ^ 2N2(g) + 02(g)- Jf = 3.5 * 10 mol JL
120. When 1 mole of pure ethyl alcohol (C2HsOH) is mixed with 1 mole of
acetic add at 25°CJ the equilibrium mixture contains 2/3 mole each of
ester and water .
C2HSOHC0+CH3COOH(l) CH3COOC?Hs(0 + H20
The A G° for the reaction at 298 K is : '
(a) 3435 J (b) 4 J (c) -3435 J (d) Zero
121. The value of A G° for a reaction in aqueous phase having Kc = 1, would
be ;
(a)-ST tbj -1 (c) 0 (d) +RT
122. A plot of Gibbs energy of a reaction mixture against the extent of the
reaction is :
(a) minimum at equilibrium (b) zero at equilibrium
(c) maximum at equilibrium (d) None of these
123. For the reaction at 300 K
A(g) ^ V(g) + 5(g)
ArH° = - 30 kJ/mol, ArS° = -0.1 kJ.
1 1
K" . mol" What is the value of equilibrium constant?
(a) 0 (b) 1 (0 10 (d) None of these
124. Solid Ca(HC03)2 decomposes as
Ca(HC03)2{s) CaC03(s) + C02(g) +
H20[g)
If the total pressure is 0.2 bar at 420 K: what is the standard free energy
change for the given reaction (A^G51)?
(a) 840 kJ/mol (b) 3.86 kJ/mol (c) 6,98 kJ/mol (d) 16,083 kj/mol

125. The standard free energy change of a reaction is AGa= -115 kJ at 298 K.
Calculate the value of log10krp (fi =8.314 JKT1 mol'1)
1. The following equilibrium constants were determined at 1120 K :
“ 2CO(g) C(s) + C02tg); Jt„ = 10“14 atm-1
CO(g) + Cl2(g) ** COCl2(g); KP2 =6X10"3 atm'1
What is the equilibrium constant Kc for the following reaction at 1120 K :
‘ C(s) + C02(g] + 2Cl2Cg) ^ 2COCla(g)
(a) 3.31 x 1011 M_1 (b) 5.5 x 1010 M_1 (c) 5.51 x 106 M’1
(d) None of these
2. One mole of N2(g) is mixed with 2 moles of H2(g) in a 4 litre vessel. If
50% of N2(g) is converted to NH3(g) by the following reaction :
N2(*) + 3H2Cg) ** 2NH3fc)
What will be the value of Kc for the following equilibrium?
NH3(g) =F± iN2Cg) + |H2(g)
i '
(a) 256 (b) 16 (c) — (d) None of these
16

4. Assume that the decomposition of HN03 can be represented by the

following equation
4HN03(g) ^ 4N02(g) + 2H20(g) + 02(g)
and the reaction approaches equilibrium at 400 K temperature and 30 atm
pressure. At equilibrium partial pressure of HN03 is 2 atm.
Calculate Kc in (mol/L)3 at 400 K :
(Use : R - 0.08 atm-L/moHO
(a) 4 (b) 8 (0 16 (d) 32
5* For the equilibrium
LiCl 3NH3(s) ^ LiCl -NH3(s} 4-2NH3(g);
X, =9 atm3 at 37°C. A 5 litre vessel contains 0.1 mole of LiCl NH3. How
many moles of NH3
P
should be added to the flask at this temperature to derive the backward
reaction for completion?
Use : R = 0.082 atin-iymoi K '
(a) 0.2 (b> 0.59 (c) 0.69 (d) 0.79

6. Ammonium carbamate dissociates as

’ NH2COONH4 (sj ^ 2NH3 (g) + C02(g)
In a closed vessel containing ammonium carbamate in equilibrium,
ammonia is added such that partial pressure of NH3 now equals to the
original total pressure. Calculate the ratio of partial pressure of C02 now to
the original partial pressure of C02 :
(a) 4 (b) 9 (c) - (d) -
9 9
 CAU
KHO
7. For the reaction C2H6(g) T=^ C2H4(g) + H2(g)
Kp is 5 x 10“2 atm. Calculate the mole per cent of C2H6(g) at equilibrium
if pure C2H6 at 1 atm is passed over a suitable catalyst at 900 K :
Ea) 20 (b) 33.33 (c) 66.66 (d) None of these
8. 2NQBr(g) 2NO(g) + Br2(g). If nitrosyl bromide (NOBr) is 40%
dissociated at certain temp, and a total pressure of 0.30 atm. Kp for the
reaction 2NOfe) + Br2(g) ^ 2NOBr(g)
is:
(a) 45 (b) 25 (c) 0.022 (d) 0.25
9* Consider the partial decomposition of A as
2A(g) ^ 2B(g) + C(g)
10* At a certain temperature and 2 atm pressure equilibrium constant (AT^) is
25 for the reaction
S02(g) + N02(g) ^ S03(g) + NO(g)
Initially if we take 2 moles of each of the four gases and 2 moles of inert
gas, what would be the equilibrium partial pressure of N02?
(a) 1.33 atm (b) 0.1665atm (c) 0.133atm (d)None of these
11. 0.020 g of selenium vapour at equilibrium occupying a volume of 2,463
mL at 1 atm and 27°C. The selenium is in a state of equilibrium according
to reaction
3Se2(g) ^ Se6(g)
What is the degree of association of selenium?
(At. wt. of Se = 79)
(a) 0.205 (b) 0.315 (c) 0.14 (d)None of these
12. Determine the degree of association (polymerization) for the reaction in
aqueous solution
6HCHO ^ C6H13Oe
If observed (mean) molar mass of HCHO and is 150 :
(a) 0.50 fo) 0.833 (c) 0.90 (d)0.96
13. A reaction system in equilibrium according to reaction 2S0 2(g) + 02(g) ^
2S03(g)inone
litre vessel at a given temperature was found to be 0.12 mole each ofS02
and SO3 and 5 mole of 02. In another vessel of one litre contains 32 g of
S02 at the same temperature. What mass of 02 must be added to this
vessel in order tliat at equilibrium 20% of S02 is
oxidized to S03?
(a) 0.4125 g (b) 11,6 g (c) 1.6 g (d)None of these

14. The equilibrium constant Kp for the reaction

N204(g) ^ 2N02(g)is4.5
What would be the average molar mass (in g/mol) of an equilibrium
mixture of N20 4 and NO2 formed by the dissociation of pure N204 at a
total pressure of 2 atm?
(a) 69 (b) 57.5 (c) 80.5 (d)85.5
15. A flask containing 0.5 atm pressure of A2(g), some solid AB added into
flask which undergoes dissociation according to 2AB{s) A2(g) + B2(g)
iffp = 0,06 atm3
The total pressure (in atm) at equilibrium is :
(a) 0.70 (b) 0.6 (c) 0.10 (d) None of these
16. A vessel of 250 litre was filled with 0.01 mole of Sb2S3 and 0.01 mole of
H2 to attain the
equilibrium at 440<>C as '
Sb2S3(s) + 3H2(g) ^ 2Sb(s)+ 3H2S(g)
After equilibrium, the H2S formed was analysed by dissolved it in water
and treating with excess of Pb2f to give 1.19 g of PbS as precipitate. What
 is the value of Kc at 440°C? CAU
KHO
(a) 1 (b) 2 (c) 4 (d) 8
12
17. For the reaction 2A(g) + B(g) ^ C(g) + D(g);Kc =10 . If the initial
moles of A, B, C and B arc 2,1, 7 and 3 moles respectively in a one
litre vessel. What is the equilibrium concentration of A?
(a)4xl0- 4 (b) 2x10 4 (C) 10-4 (d) 8 x 10-4
18. The equilibrium constant for the reaction in aqueous solution
H3BO3 + glycerin (H3B03-glycerin) is 0.90,
How many moles of glycerin should be added per litre of 0.10 M H3B03
so that 80% of the HJB03 is converted to the boric-acid-glycerin complex?
(a) 4.44 (b) 4.52 (c) 3.6 (d) 0 08
19. Rate of diffusion of ozonized oxygen is 0.4/5 times that of pure
oxygen. What is the per cent degree of association of oxygen assuming
pure 02 in the sample initially?
(a) 20 (b) 40 (c) 60 (d) Noneof these
20. One mole of SOs was placed in a two litre vessel at a certain
temperature. The following equilibrium was established in the vessel
2S03(g) ^ 2S02(g) + 02(g)
the equilibrium mixture reacted with 0.2 mole KMn04 in acidic medium.
Hence, Kc is :
(a) 0.50 (b) 0.25
(e) 0.125 (d) None of these
21. At SOO’C, the following equilibrium is established as
Fa(g) ** 2F(g)
The composition of equilibrium may be determined by measuring the
rate of effusion of die mixture through a pin hole. It is found that at
800°C and 1 atm mixture effuses 1.6 times as fast as SO2 effuses
under the similar renditions. (At. wt. of F = 19). What is the value of
Kp (in atm)? CAU HOI NHIEU LtfA
CHON
(a) 0.315 (b) 0.685
(c) 0.46 (d) 1.49
22. The equilibrium constant for the ionization of )?NH2(g) in water as
*NH2Cg)+ H20(f) ^ JiNH^(ag) + OH-_(aq) is 8 x 1QjS
at 25°C, Find the pH of a solution at equilibrium when pressure of
FtNH2(g) is 0.5 bar :
(d) None
(a) »12.3 (b) ~ 11.3 (c) I
*11.45
23. Calculate ArG for the reaction at 27eC
H2(g) + 2Ag"(oq) ** 2Ag{s) + 2H*{crq)
Given : - 0.5 bar; [Ag+] - 10's M;
[H+] = 10'3 Mi ArG° [Ag+ (aq)] » 77.1 kJ/mol (a) -
154.2 kf/mol (b) -178.9
kJ/mol
(c) -129.5 kJ/mol ' (d) None of these
24. When N2OS is heated at cenain temperature, it dissociates as N 2G5(g) ^
N203(g)-f 02(g); Kc =2.5. At the same time N203 also decomposes as ;
N203(g) ^ N20(g) + 02(g). If initially 4.0 moles of N2OE are taken in 1.0
of N2OS is (a)
1.0 JW (b) 1.5 M (c) 2.166 M (d) 1.846 M
litre flask and allowed to dissociation, concentration of 02 at equilibrium
is 2.5 M. Equilibrium concentration
25. Two solid compounds X and Y dissociates at a cenain temperature as
follows 3 3
’~ atm
X(s) ^ A(g) + 26(g); =

9x10' 3
’ atm 3

7(S) ^ 28(g) + C(g); -4.5x10-

The total pressure of gases over a mixture of X and Y is :
(a) 4,5 atm (b) 0.45 atm (c) 0.6 atm (d) None of these
 1
1. A catalyst :
(a) increases the average kinetic energy of reacting molecules '
(b) decreases the activation
energy fc) can alters the
reaction mechanism
(d) can change p re-exponential factor
2. Which of the following is correct about the chemical equilibrium?
[a) (hG)T>p,=0
(tO Equilibrium constant is independent of initial concentration of
reactants
(c) Catalyst has no effect on
equilibrium state Cd) Reaction stops
at equilibrium
3. For the reaction
AB2(g) ^ AB(g) + B(g)
If a. is negligiable wxt. 1 then degree of dissociation (a) of AB2 is
proportional to :
(a) ~ 00 ^ (c) ~L (d) 4V
P v 4P
4< Consider the reactions given below. In which cases will the reaction
proceed toward right by increasing the pressure?
(a)----------------------------------- 4HCl(g) + 02(g) > Xl2(g) + 2H20(g3
(b)----------------------------------- a2(g) + HaO(g) ► 2HCl(g) + io2Cg)
(c) C02(g) + 4H3(g>- t CH4(g) + 2H20(g)
(d) N2{g) + 02(g) - -* 2NO(g)
5. Ammonia is a weak base that reacts with water according to the equation
NH3(aq) +H20(l) ^ NHUa<7) + Otr(aq)
Select the correct option (s) that can increase the moles of
ammonium ion in water: fa) Addition of HC1 {b) Addition of
NaOH
(c) Addition of NH4C1 {dj Addition of HsO
6. Consider the reaction X0(g)+02Cg) ^ 2C02Cg) +
Heat Under what conditions shift is
undeterminable?
(a) Addition of 02 and decrease in volume
(b) Addition of CO and removal of C02 at constant volume
 CAU HOI NHIEU LtfA
CHON
(c] Increase in temperature and decrease in volume
(d) Addition of CO and increase in temperature at constant volume
7. What will be the effect of addition of catalyst at constant temperature?
(a) The equilibrium constant will remain constant
(b) A H of the reaction will remain constant
(c) kf and kb will increase upto same extent
(d) equilibrium composition will change
8. For the reaction PCls(g) ^ PCl3{g) + C\2(g), the forward reaction at
constant temperature
is favoured by: •
(a) introducing an inert gas at constant volume
(b) introducing chlorine gas at constant volume
(c) introducing an inert gas at
constant pressure (d> increasing the
volume of the container
9. For the reaction : Cl2(g) + 3F2(g) ^ 2ClF3(g); AH=-
329kJ, dissociation of ClF3(g} will be favoured by :
(a) increasing the temperature
(b) increasing the volume of the container
(c) adding of F3 gas
(d) adding of inert gas at constant pressure

10. Increase in the pressure for the following equilibrium :

H2O(0 ^ H20(g), result in the:
(a) formation of more H20(f) (b) formation of more H-zO(g)
(c) increase in b.p. of H2O(0 (d) decrease in b.p. of H20(!) .
11. Heating a II group metal carbonate leads to decomposition as :
BaC03(s) ^ Ba0Cs) + C02(g) '
Equilibrium will shift left
(a) by addition of BaO(s) (b) by addition of C02(&)
(c) by decreasing the temperature(d) by
decreasing the volume of the vessel
12. N2(g) and H2(g) are allowed to react in a closed vessel at
given temp, and pressure for the formation of NH3(g)[N2(g) + 3H2(g)
^ 2NH3(g) + 22.4 kcal] if He(g) is added at equilibrium at constant
pressure then which is/are correct ?
(a) Concentration of N2(g), H2(g) and NH3(g) decrease.
fbf Moles of NH3(g) decreases. ' -
(c) The extent of cooling depends on amount of He(g) added.
(d) Concentration of N2 and H2 increases and concentration of NH3
decreases.