Equilibrium Practice Questions - DPP for JEE

 Page 1


PART-I (Single Correct MCQs)
1. K
c
 for the reaction
N
2
 (g) + O
2
 (g)  2NO (g)
at 300 K is 4.0 × 10
–6
. K
p
 for the above reaction will be
(R = 2 cal mol
–1
 K
–1
)
(a) 2.4 × 10
–3
(b) 4 × 10
–6
(c) 4 × 10
–6
 (RT)
2
(d) 16 × 10
–12
2. The dissociation constant of a weak acid is 1 × 10
– 4
. In order to prepare
a buffer solution with a pH = 5 the [Salt]/[Acid] ratio should be
(a) 1 : 10
(b) 4 : 5
(c) 10 : 1
(d) 5 : 4
3. The exothermic formation of ClF
3
 is represented by the equation :
Page 2


PART-I (Single Correct MCQs)
1. K
c
 for the reaction
N
2
 (g) + O
2
 (g)  2NO (g)
at 300 K is 4.0 × 10
–6
. K
p
 for the above reaction will be
(R = 2 cal mol
–1
 K
–1
)
(a) 2.4 × 10
–3
(b) 4 × 10
–6
(c) 4 × 10
–6
 (RT)
2
(d) 16 × 10
–12
2. The dissociation constant of a weak acid is 1 × 10
– 4
. In order to prepare
a buffer solution with a pH = 5 the [Salt]/[Acid] ratio should be
(a) 1 : 10
(b) 4 : 5
(c) 10 : 1
(d) 5 : 4
3. The exothermic formation of ClF
3
 is represented by the equation :
 ? 2ClF
3
(g) ;  = – 329 kJ
Which of the following will increase the quantity of ClF
3
 in an equilibrium
mixture of Cl
2
, F
2
 and ClF
3
?
(a) Adding 
(b) Increasing the volume of the container
(c) Removing Cl
2
(d) Increasing the temperature
4. The K
sp
 of Ag
2
CrO
4
, AgCl, AgBr and AgI are respectively, 1.1 × 10
–12
,
1.8 × 10
–10
, 5.0 × 10
–13
, 8.3 × 10
–17
. Which one of the following salts will
precipitate last if AgNO
3
 solution is added to the solution containing
equal moles of NaCl, NaBr, NaI and Na
2
CrO
4
?
(a) AgCl
(b) AgBr
(c) Ag
2
CrO
4
(d) AgI
5. MY and NY
3
, two nearly insoluble salts, have the same K
sp
 values of 6.2
× 10
–13
 at room temperature. Which statement would be true in regard to
MY and NY
3
 ?
(a) The molar solubilities of MY and NY
3
 in water are identical.
(b) The molar solubility of MY in water is less than that of NY
3
(c) The salts MY and NY
3
 are more soluble in 0.5 M KY than in pure
water.
(d) The addition of the salt of KY to solution of MY and NY
3
 will have no
effect on their solubilities.
6. The following reaction is performed at 298 K.
2NO(g) + O
2
(g) ? 2NO
2
(g)
The standard free energy of formation of NO(g) is 86.6 kJ/mol at 298 K.
What is the standard free energy of formation of NO
2
(g) at 298 K? (K
p
 =
Page 3


PART-I (Single Correct MCQs)
1. K
c
 for the reaction
N
2
 (g) + O
2
 (g)  2NO (g)
at 300 K is 4.0 × 10
–6
. K
p
 for the above reaction will be
(R = 2 cal mol
–1
 K
–1
)
(a) 2.4 × 10
–3
(b) 4 × 10
–6
(c) 4 × 10
–6
 (RT)
2
(d) 16 × 10
–12
2. The dissociation constant of a weak acid is 1 × 10
– 4
. In order to prepare
a buffer solution with a pH = 5 the [Salt]/[Acid] ratio should be
(a) 1 : 10
(b) 4 : 5
(c) 10 : 1
(d) 5 : 4
3. The exothermic formation of ClF
3
 is represented by the equation :
 ? 2ClF
3
(g) ;  = – 329 kJ
Which of the following will increase the quantity of ClF
3
 in an equilibrium
mixture of Cl
2
, F
2
 and ClF
3
?
(a) Adding 
(b) Increasing the volume of the container
(c) Removing Cl
2
(d) Increasing the temperature
4. The K
sp
 of Ag
2
CrO
4
, AgCl, AgBr and AgI are respectively, 1.1 × 10
–12
,
1.8 × 10
–10
, 5.0 × 10
–13
, 8.3 × 10
–17
. Which one of the following salts will
precipitate last if AgNO
3
 solution is added to the solution containing
equal moles of NaCl, NaBr, NaI and Na
2
CrO
4
?
(a) AgCl
(b) AgBr
(c) Ag
2
CrO
4
(d) AgI
5. MY and NY
3
, two nearly insoluble salts, have the same K
sp
 values of 6.2
× 10
–13
 at room temperature. Which statement would be true in regard to
MY and NY
3
 ?
(a) The molar solubilities of MY and NY
3
 in water are identical.
(b) The molar solubility of MY in water is less than that of NY
3
(c) The salts MY and NY
3
 are more soluble in 0.5 M KY than in pure
water.
(d) The addition of the salt of KY to solution of MY and NY
3
 will have no
effect on their solubilities.
6. The following reaction is performed at 298 K.
2NO(g) + O
2
(g) ? 2NO
2
(g)
The standard free energy of formation of NO(g) is 86.6 kJ/mol at 298 K.
What is the standard free energy of formation of NO
2
(g) at 298 K? (K
p
 =
1.6 × 10
12
)
(a) 86600 – 
(b) 0.5[2 × 86,600 – R(298) ln(1.6 × 10
12
)]
(c) R(298) ln(1.6 × 10
12
) – 86600
(d) 86600 + R(298) ln(1.6 × l0
12
)
7. The equilibrium constant of the following are :
N
2
 + 3H
2
  ? 2NH
3
K
1
N
2
 + O
2
  ? 2NO K
2
K
3
The equilibrium constant (K) of the reaction :
  2NO + 3H
2
O, will be;
(a)
(b) K
2
K
3
/K
1
(c)
(d)
8. The %yield of ammonia as a function of time in the reaction
N
2
(g) + 3H
2
(g) ? 2NH
3
(g), ?H < 0 at (P, T
1
) is given below
If this reaction is conducted at (P, T
2
), with T
2
 > T
1
, the %yield of ammonia
as a function of time is represented by
Page 4


PART-I (Single Correct MCQs)
1. K
c
 for the reaction
N
2
 (g) + O
2
 (g)  2NO (g)
at 300 K is 4.0 × 10
–6
. K
p
 for the above reaction will be
(R = 2 cal mol
–1
 K
–1
)
(a) 2.4 × 10
–3
(b) 4 × 10
–6
(c) 4 × 10
–6
 (RT)
2
(d) 16 × 10
–12
2. The dissociation constant of a weak acid is 1 × 10
– 4
. In order to prepare
a buffer solution with a pH = 5 the [Salt]/[Acid] ratio should be
(a) 1 : 10
(b) 4 : 5
(c) 10 : 1
(d) 5 : 4
3. The exothermic formation of ClF
3
 is represented by the equation :
 ? 2ClF
3
(g) ;  = – 329 kJ
Which of the following will increase the quantity of ClF
3
 in an equilibrium
mixture of Cl
2
, F
2
 and ClF
3
?
(a) Adding 
(b) Increasing the volume of the container
(c) Removing Cl
2
(d) Increasing the temperature
4. The K
sp
 of Ag
2
CrO
4
, AgCl, AgBr and AgI are respectively, 1.1 × 10
–12
,
1.8 × 10
–10
, 5.0 × 10
–13
, 8.3 × 10
–17
. Which one of the following salts will
precipitate last if AgNO
3
 solution is added to the solution containing
equal moles of NaCl, NaBr, NaI and Na
2
CrO
4
?
(a) AgCl
(b) AgBr
(c) Ag
2
CrO
4
(d) AgI
5. MY and NY
3
, two nearly insoluble salts, have the same K
sp
 values of 6.2
× 10
–13
 at room temperature. Which statement would be true in regard to
MY and NY
3
 ?
(a) The molar solubilities of MY and NY
3
 in water are identical.
(b) The molar solubility of MY in water is less than that of NY
3
(c) The salts MY and NY
3
 are more soluble in 0.5 M KY than in pure
water.
(d) The addition of the salt of KY to solution of MY and NY
3
 will have no
effect on their solubilities.
6. The following reaction is performed at 298 K.
2NO(g) + O
2
(g) ? 2NO
2
(g)
The standard free energy of formation of NO(g) is 86.6 kJ/mol at 298 K.
What is the standard free energy of formation of NO
2
(g) at 298 K? (K
p
 =
1.6 × 10
12
)
(a) 86600 – 
(b) 0.5[2 × 86,600 – R(298) ln(1.6 × 10
12
)]
(c) R(298) ln(1.6 × 10
12
) – 86600
(d) 86600 + R(298) ln(1.6 × l0
12
)
7. The equilibrium constant of the following are :
N
2
 + 3H
2
  ? 2NH
3
K
1
N
2
 + O
2
  ? 2NO K
2
K
3
The equilibrium constant (K) of the reaction :
  2NO + 3H
2
O, will be;
(a)
(b) K
2
K
3
/K
1
(c)
(d)
8. The %yield of ammonia as a function of time in the reaction
N
2
(g) + 3H
2
(g) ? 2NH
3
(g), ?H < 0 at (P, T
1
) is given below
If this reaction is conducted at (P, T
2
), with T
2
 > T
1
, the %yield of ammonia
as a function of time is represented by
(a)
(b)
(c)
(d)
9. Concentration of the Ag
+
 ions in a saturated solution of Ag
2
C
2
O
4
 is 2.2 ×
10
–4 
mol L
–1
. Solubility product of Ag
2
C
2
O
4
 is :-
(a) 2.66 × 10
–12
(b) 4.5 × 10
–11
(c) 5.3 × 10
–12
(d) 2.42 × 10
–8
10. The degree of dissociation of  obeying the equilibrium 
Page 5


PART-I (Single Correct MCQs)
1. K
c
 for the reaction
N
2
 (g) + O
2
 (g)  2NO (g)
at 300 K is 4.0 × 10
–6
. K
p
 for the above reaction will be
(R = 2 cal mol
–1
 K
–1
)
(a) 2.4 × 10
–3
(b) 4 × 10
–6
(c) 4 × 10
–6
 (RT)
2
(d) 16 × 10
–12
2. The dissociation constant of a weak acid is 1 × 10
– 4
. In order to prepare
a buffer solution with a pH = 5 the [Salt]/[Acid] ratio should be
(a) 1 : 10
(b) 4 : 5
(c) 10 : 1
(d) 5 : 4
3. The exothermic formation of ClF
3
 is represented by the equation :
 ? 2ClF
3
(g) ;  = – 329 kJ
Which of the following will increase the quantity of ClF
3
 in an equilibrium
mixture of Cl
2
, F
2
 and ClF
3
?
(a) Adding 
(b) Increasing the volume of the container
(c) Removing Cl
2
(d) Increasing the temperature
4. The K
sp
 of Ag
2
CrO
4
, AgCl, AgBr and AgI are respectively, 1.1 × 10
–12
,
1.8 × 10
–10
, 5.0 × 10
–13
, 8.3 × 10
–17
. Which one of the following salts will
precipitate last if AgNO
3
 solution is added to the solution containing
equal moles of NaCl, NaBr, NaI and Na
2
CrO
4
?
(a) AgCl
(b) AgBr
(c) Ag
2
CrO
4
(d) AgI
5. MY and NY
3
, two nearly insoluble salts, have the same K
sp
 values of 6.2
× 10
–13
 at room temperature. Which statement would be true in regard to
MY and NY
3
 ?
(a) The molar solubilities of MY and NY
3
 in water are identical.
(b) The molar solubility of MY in water is less than that of NY
3
(c) The salts MY and NY
3
 are more soluble in 0.5 M KY than in pure
water.
(d) The addition of the salt of KY to solution of MY and NY
3
 will have no
effect on their solubilities.
6. The following reaction is performed at 298 K.
2NO(g) + O
2
(g) ? 2NO
2
(g)
The standard free energy of formation of NO(g) is 86.6 kJ/mol at 298 K.
What is the standard free energy of formation of NO
2
(g) at 298 K? (K
p
 =
1.6 × 10
12
)
(a) 86600 – 
(b) 0.5[2 × 86,600 – R(298) ln(1.6 × 10
12
)]
(c) R(298) ln(1.6 × 10
12
) – 86600
(d) 86600 + R(298) ln(1.6 × l0
12
)
7. The equilibrium constant of the following are :
N
2
 + 3H
2
  ? 2NH
3
K
1
N
2
 + O
2
  ? 2NO K
2
K
3
The equilibrium constant (K) of the reaction :
  2NO + 3H
2
O, will be;
(a)
(b) K
2
K
3
/K
1
(c)
(d)
8. The %yield of ammonia as a function of time in the reaction
N
2
(g) + 3H
2
(g) ? 2NH
3
(g), ?H < 0 at (P, T
1
) is given below
If this reaction is conducted at (P, T
2
), with T
2
 > T
1
, the %yield of ammonia
as a function of time is represented by
(a)
(b)
(c)
(d)
9. Concentration of the Ag
+
 ions in a saturated solution of Ag
2
C
2
O
4
 is 2.2 ×
10
–4 
mol L
–1
. Solubility product of Ag
2
C
2
O
4
 is :-
(a) 2.66 × 10
–12
(b) 4.5 × 10
–11
(c) 5.3 × 10
–12
(d) 2.42 × 10
–8
10. The degree of dissociation of  obeying the equilibrium 
+ is related to the equilibrium pressure by
(a)
(b)
(c)
(d)
11. A 20 litre container at 400 K contains CO
2
(g) at pressure 0.4 atm and an
excess of SrO (neglect the volume of solid SrO). The volume of the
container is now decreased by moving the movable piston fitted in the
container. The maximum volume of the container, when pressure of CO
2
attains its maximum value, will be :-
(Given that :  SrCO
3
 (s)  ? SrO (s) + CO
2
(g), Kp = 1.6 atm)
(a) 10 litre
(b) 4 litre
(c) 2 litre
(d) 5 litre
12. The first and second dissociation constants of an acid H
2
A are 1.0 × 10
–5
and 5.0 × 10
–10
 respectively. The overall dissociation constant of the acid
will be
(a) 0.2 × 10
5
(b) 5.0 × 10
–5
(c) 5.0 × 10
15
(b) 5.0 × 10
–15
13. In a saturated solution of the sparingly soluble strong  electrolyte AgIO
3
(molecular mass = 283) the equilibrium which sets is AgIO
3
(s)