Chemical Equilibrium: JEE Mains Previous Year Questions (2021-2024) | Chemistry for JEE Main & Advanced PDF Download

 Page 1


 
 
 
2024 
 
Q1 - 2024 (29 Jan Shift 1) 
For the reaction N
2
O
4
(g) ? 2NO
2
(g), K
p
= 0.492 atm at 300K. K
c
 for the reaction at same 
temperature is  _____ × 10
-2
. 
(Given : R = 0.082Latmmol
-1
K
-1
 ) 
 
Q2 - 2024 (29 Jan Shift 2) 
The following concentrations were observed at 500K for the formation of NH
3
 from 
N
2
 and H
2
. At equilibrium :  N
2
 = 2 × 10
-2
M, H
2
 = 3 × 10
-2
M and  NH
3
 = 1.5 ×
10
-2
M. Equilibrium constant for the reaction is _____ 
 
Q3 - 2024 (31 Jan Shift 1) 
For the given reaction, choose the correct expression of K
C
 from the following:- 
Fe
(aq )
3+
+ SCN
(aq )
-
? (FeSCN)
(aq )
2+
 
(1) K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
(2) K
C
=
 Fe
3+
  SCN
-
 
 FeSCN
2+
 
 
(3) K
C
=
 FeSCN
2+
 
 Fe
3+
 
2
 SCN
-
 
2
 
(4) K
C
=
 FeSCN
2+
 
2
 Fe
3+
  SCN
-
 
 
 
Q4 - 2024 (31 Jan Shift 2) 
A
(g)
? B
(g)
+
C
2
(g) The correct relationship between ?? ?? ,?? and equilibrium pressure ?? is 
(1) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
1/2
 
(2) ?? ?? =
?? 3/2
?? 1/2
(2+?? )
1/2
(1-?? )
 
(3) ?? ?? =
?? 1/2
?? 3/2
(2+?? )
3/2
 
Page 2


 
 
 
2024 
 
Q1 - 2024 (29 Jan Shift 1) 
For the reaction N
2
O
4
(g) ? 2NO
2
(g), K
p
= 0.492 atm at 300K. K
c
 for the reaction at same 
temperature is  _____ × 10
-2
. 
(Given : R = 0.082Latmmol
-1
K
-1
 ) 
 
Q2 - 2024 (29 Jan Shift 2) 
The following concentrations were observed at 500K for the formation of NH
3
 from 
N
2
 and H
2
. At equilibrium :  N
2
 = 2 × 10
-2
M, H
2
 = 3 × 10
-2
M and  NH
3
 = 1.5 ×
10
-2
M. Equilibrium constant for the reaction is _____ 
 
Q3 - 2024 (31 Jan Shift 1) 
For the given reaction, choose the correct expression of K
C
 from the following:- 
Fe
(aq )
3+
+ SCN
(aq )
-
? (FeSCN)
(aq )
2+
 
(1) K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
(2) K
C
=
 Fe
3+
  SCN
-
 
 FeSCN
2+
 
 
(3) K
C
=
 FeSCN
2+
 
 Fe
3+
 
2
 SCN
-
 
2
 
(4) K
C
=
 FeSCN
2+
 
2
 Fe
3+
  SCN
-
 
 
 
Q4 - 2024 (31 Jan Shift 2) 
A
(g)
? B
(g)
+
C
2
(g) The correct relationship between ?? ?? ,?? and equilibrium pressure ?? is 
(1) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
1/2
 
(2) ?? ?? =
?? 3/2
?? 1/2
(2+?? )
1/2
(1-?? )
 
(3) ?? ?? =
?? 1/2
?? 3/2
(2+?? )
3/2
 
(4) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
3/2
 
 
 
Answer Key 
 
Q1 (2) 
 
Q2 (417) 
 
Q3 (1) 
 
Q4 (2) 
 
 
 
Solutions 
Q1 
K
P
= K
C
· (RT)
?n
g
 
?n
g
= 1 
? K
c
=
K
P
RT
=
0.492
0.082 × 300
= 2 × 10
-2
 
 
Q2 
K
C
=
 NH
3
 
2
 N
2
  H
2
 
3
 
K
C
=
 1.5 × 10
-2
 
2
 2 × 10
-2
 × 3 × 10
-2
 
3
 
K
C
= 417 
 
Q3 
K
C
=
 Products ion conc. 
 Reactants ion conc. 
 
K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
Page 3


 
 
 
2024 
 
Q1 - 2024 (29 Jan Shift 1) 
For the reaction N
2
O
4
(g) ? 2NO
2
(g), K
p
= 0.492 atm at 300K. K
c
 for the reaction at same 
temperature is  _____ × 10
-2
. 
(Given : R = 0.082Latmmol
-1
K
-1
 ) 
 
Q2 - 2024 (29 Jan Shift 2) 
The following concentrations were observed at 500K for the formation of NH
3
 from 
N
2
 and H
2
. At equilibrium :  N
2
 = 2 × 10
-2
M, H
2
 = 3 × 10
-2
M and  NH
3
 = 1.5 ×
10
-2
M. Equilibrium constant for the reaction is _____ 
 
Q3 - 2024 (31 Jan Shift 1) 
For the given reaction, choose the correct expression of K
C
 from the following:- 
Fe
(aq )
3+
+ SCN
(aq )
-
? (FeSCN)
(aq )
2+
 
(1) K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
(2) K
C
=
 Fe
3+
  SCN
-
 
 FeSCN
2+
 
 
(3) K
C
=
 FeSCN
2+
 
 Fe
3+
 
2
 SCN
-
 
2
 
(4) K
C
=
 FeSCN
2+
 
2
 Fe
3+
  SCN
-
 
 
 
Q4 - 2024 (31 Jan Shift 2) 
A
(g)
? B
(g)
+
C
2
(g) The correct relationship between ?? ?? ,?? and equilibrium pressure ?? is 
(1) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
1/2
 
(2) ?? ?? =
?? 3/2
?? 1/2
(2+?? )
1/2
(1-?? )
 
(3) ?? ?? =
?? 1/2
?? 3/2
(2+?? )
3/2
 
(4) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
3/2
 
 
 
Answer Key 
 
Q1 (2) 
 
Q2 (417) 
 
Q3 (1) 
 
Q4 (2) 
 
 
 
Solutions 
Q1 
K
P
= K
C
· (RT)
?n
g
 
?n
g
= 1 
? K
c
=
K
P
RT
=
0.492
0.082 × 300
= 2 × 10
-2
 
 
Q2 
K
C
=
 NH
3
 
2
 N
2
  H
2
 
3
 
K
C
=
 1.5 × 10
-2
 
2
 2 × 10
-2
 × 3 × 10
-2
 
3
 
K
C
= 417 
 
Q3 
K
C
=
 Products ion conc. 
 Reactants ion conc. 
 
K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
Q4 
 
 
Page 4


 
 
 
2024 
 
Q1 - 2024 (29 Jan Shift 1) 
For the reaction N
2
O
4
(g) ? 2NO
2
(g), K
p
= 0.492 atm at 300K. K
c
 for the reaction at same 
temperature is  _____ × 10
-2
. 
(Given : R = 0.082Latmmol
-1
K
-1
 ) 
 
Q2 - 2024 (29 Jan Shift 2) 
The following concentrations were observed at 500K for the formation of NH
3
 from 
N
2
 and H
2
. At equilibrium :  N
2
 = 2 × 10
-2
M, H
2
 = 3 × 10
-2
M and  NH
3
 = 1.5 ×
10
-2
M. Equilibrium constant for the reaction is _____ 
 
Q3 - 2024 (31 Jan Shift 1) 
For the given reaction, choose the correct expression of K
C
 from the following:- 
Fe
(aq )
3+
+ SCN
(aq )
-
? (FeSCN)
(aq )
2+
 
(1) K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
(2) K
C
=
 Fe
3+
  SCN
-
 
 FeSCN
2+
 
 
(3) K
C
=
 FeSCN
2+
 
 Fe
3+
 
2
 SCN
-
 
2
 
(4) K
C
=
 FeSCN
2+
 
2
 Fe
3+
  SCN
-
 
 
 
Q4 - 2024 (31 Jan Shift 2) 
A
(g)
? B
(g)
+
C
2
(g) The correct relationship between ?? ?? ,?? and equilibrium pressure ?? is 
(1) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
1/2
 
(2) ?? ?? =
?? 3/2
?? 1/2
(2+?? )
1/2
(1-?? )
 
(3) ?? ?? =
?? 1/2
?? 3/2
(2+?? )
3/2
 
(4) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
3/2
 
 
 
Answer Key 
 
Q1 (2) 
 
Q2 (417) 
 
Q3 (1) 
 
Q4 (2) 
 
 
 
Solutions 
Q1 
K
P
= K
C
· (RT)
?n
g
 
?n
g
= 1 
? K
c
=
K
P
RT
=
0.492
0.082 × 300
= 2 × 10
-2
 
 
Q2 
K
C
=
 NH
3
 
2
 N
2
  H
2
 
3
 
K
C
=
 1.5 × 10
-2
 
2
 2 × 10
-2
 × 3 × 10
-2
 
3
 
K
C
= 417 
 
Q3 
K
C
=
 Products ion conc. 
 Reactants ion conc. 
 
K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
Q4 
 
 
P- 1
Numerical 
 
 
 
 
JEE Main 2023 (Online) 12th April Morning Shift 
 
Q.1. 20 mL of  0.1 M NaOH is added to  50 mL of  0.1 M acetic acid 
solution. The pH of the resulting solution is 
___________ ×10
-2
 (Nearest integer) 
JEE Main 2023 (Online) 13th April Evening Shift 
 
Q.2. 
 
(Nearest integer) 
JEE Main 2023 (Online) 13th April Morning Shift 
 
Q.3. An analyst wants to convert   1 L HCl of pH=1 to a solution 
of HCl of  pH2. The volume of water needed to do this dilution is 
_______ mL. (Nearest integer) 
Page 5


 
 
 
2024 
 
Q1 - 2024 (29 Jan Shift 1) 
For the reaction N
2
O
4
(g) ? 2NO
2
(g), K
p
= 0.492 atm at 300K. K
c
 for the reaction at same 
temperature is  _____ × 10
-2
. 
(Given : R = 0.082Latmmol
-1
K
-1
 ) 
 
Q2 - 2024 (29 Jan Shift 2) 
The following concentrations were observed at 500K for the formation of NH
3
 from 
N
2
 and H
2
. At equilibrium :  N
2
 = 2 × 10
-2
M, H
2
 = 3 × 10
-2
M and  NH
3
 = 1.5 ×
10
-2
M. Equilibrium constant for the reaction is _____ 
 
Q3 - 2024 (31 Jan Shift 1) 
For the given reaction, choose the correct expression of K
C
 from the following:- 
Fe
(aq )
3+
+ SCN
(aq )
-
? (FeSCN)
(aq )
2+
 
(1) K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
(2) K
C
=
 Fe
3+
  SCN
-
 
 FeSCN
2+
 
 
(3) K
C
=
 FeSCN
2+
 
 Fe
3+
 
2
 SCN
-
 
2
 
(4) K
C
=
 FeSCN
2+
 
2
 Fe
3+
  SCN
-
 
 
 
Q4 - 2024 (31 Jan Shift 2) 
A
(g)
? B
(g)
+
C
2
(g) The correct relationship between ?? ?? ,?? and equilibrium pressure ?? is 
(1) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
1/2
 
(2) ?? ?? =
?? 3/2
?? 1/2
(2+?? )
1/2
(1-?? )
 
(3) ?? ?? =
?? 1/2
?? 3/2
(2+?? )
3/2
 
(4) ?? ?? =
?? 1/2
?? 1/2
(2+?? )
3/2
 
 
 
Answer Key 
 
Q1 (2) 
 
Q2 (417) 
 
Q3 (1) 
 
Q4 (2) 
 
 
 
Solutions 
Q1 
K
P
= K
C
· (RT)
?n
g
 
?n
g
= 1 
? K
c
=
K
P
RT
=
0.492
0.082 × 300
= 2 × 10
-2
 
 
Q2 
K
C
=
 NH
3
 
2
 N
2
  H
2
 
3
 
K
C
=
 1.5 × 10
-2
 
2
 2 × 10
-2
 × 3 × 10
-2
 
3
 
K
C
= 417 
 
Q3 
K
C
=
 Products ion conc. 
 Reactants ion conc. 
 
K
C
=
 FeSCN
2+
 
 Fe
3+
  SCN
-
 
 
Q4 
 
 
P- 1
Numerical 
 
 
 
 
JEE Main 2023 (Online) 12th April Morning Shift 
 
Q.1. 20 mL of  0.1 M NaOH is added to  50 mL of  0.1 M acetic acid 
solution. The pH of the resulting solution is 
___________ ×10
-2
 (Nearest integer) 
JEE Main 2023 (Online) 13th April Evening Shift 
 
Q.2. 
 
(Nearest integer) 
JEE Main 2023 (Online) 13th April Morning Shift 
 
Q.3. An analyst wants to convert   1 L HCl of pH=1 to a solution 
of HCl of  pH2. The volume of water needed to do this dilution is 
_______ mL. (Nearest integer) 
litre container and heated to  725 K. At equilibrium 40% of water 
by mass reacts with carbon monoxide according to the equation : 
 
The equilibrium constant Kc×10
2
 for the reaction is ____________. 
(Nearest integer) 
JEE Main 2023 (Online) 11th April Morning Shift 
 
Q.6.   
For the given reaction, if the initial pressure is   450 mm Hg and 
the pressure at time t is   720 mm Hg at a constant 
temperature T and constant volume V. The fraction 
of A(g) decomposed under these conditions is x×10
-1
. The value 
of x is ___________ (nearest integer) 
 
JEE Main 2023 (Online) 10th April Evening Shift 
 
Q.7. The number of correct statement/s involving equilibria in 
physical processes from the following is ________ 
(A) Equilibrium is possible only in a closed system at a given 
temperature. 
(B) Both the opposing processes occur at the same rate. 
(C) When equilibrium is attained at a given temperature, the 
value of all its parameters became equal. 
(D) For dissolution of solids in liquids, the solubility is constant at 
a given temperature. 
 
JEE Main 2023 (Online) 10th April Morning Shift 
Q.4. 4.5 moles each of hydrogen and iodine is heated in a sealed 
ten litre vessel. At equilibrium, 3 moles of HI were found. The 
equilibrium constant for 
Q.5. A mixture of 1 mole of H2O and 1 mole of CO is taken in a 10
JEE Main 2023 (Online) 11th April Evening Shift