# Chemical Equilibrium of Analysis MCQ with Answers for IIT JAM 2023

Chemical Equilibrium of Analysis MCQ with Answers for IIT JAM 2023

## Chemical Equilibrium of Analysis MCQ with Answers for IIT JAM 2023

1. The temperature (T) dependence of the equilibrium constant (K) of a chemical reaction is correctly described by the following statement:

(a) For an endothermic reaction, the slope of In K vs 1/T plot is positive
(b) For an exothermic reaction, K is proportional to T
(c) For an exothermic reaction, K at a higher temperature is lower than K at a lower temperature
(d) If ΔH is independent of temperature, the change in K with T is smaller at lower temperatures.

2. The relationship between the equilibrium constant K, for the reaction:
CO(g) + 1/2O2 (g) ⇌ CO2 (g)
and the equilibrium constant K, for the reaction:
2CO(g) + O2 (g) ⇌ 2CO2 (g) is

(a) 2K1 = K2
(b) K1 = K22
(c) K1 = K2
(d) K12 = K2

3. For the reaction CO(g) + H2O ⇌ CO2 (g) + H2 (g) at a given temperature the equilibrium amount  of CO2 (g) can be increased  by :

(c) decreasing the volume  of the container
(d) increasing the amount   of CO (g)

4. N2 + 3H3 ⇌ 2NH3
Which is the correct statement if N, is added at the equilibrium condition?

(a) The equilibrium will shift to a forward direction because according to II law of thermodynamics the entropy must increase in the direction of spontaneous reaction.
(b) The condition for equilibrium is GN2 +3GH2 = 2GNH3 , where G is Gibbs free energy per mole of the gaseous species measured at that partial pressure. The condition of equilibrium is unaffected by the use of a catalyst, which increases the rate of both the forward and backward reactions to the same extent.
(c) The catalyst will increase the rate of forward reaction by a and that of backward reaction by B.
(d) Catalyst will not alter the rate of either of the reaction.

5. When two reactants A and B are mixed to give products C and D, the reaction quotient Q, at the initial stages of the reaction:

(a) is zero
(b) decrease with time
(c) independent of time
(d) increases with time

6. For the reversible reaction: N2 (g) + 3H2 (g) ⇌ 2NH3 (g) at 500°C. The value of K is 1.44 × 10-5 when partial pressure is measured in atmospheres. The corresponding value of K with a concentration in mol L-1 is:

(a) 1.44 × 10-5/(0.082 × 500)2
(b) 1.44 × 10-5/(8.314 × 773)2
(c) 1.44 × 10-5/(0.082 × 500)-2
(d) 1.44 × 10-5/(0.082 × 773)-2

7. At constant temperature, the equilibrium constant (Kp) for the decomposition reaction. N2O4 ⇌ 2NO2 is expressed by Kp = 4x2P/(1 – x2) where P is pressure, and x is the extent of decomposition. Which of the following statement is true?

(a) Kp increases with an increase of P
(b) Kp increases with an increase of x
(c) Kp increases with a decrease of x
(d) Kp remains constant with change in P or x

8. Consider the following equilibrium in a closed container: N2O4 (g) ⇌ 2NO2 (g). At a fixed temperature, the volume of the reaction container is halved. For this change, which of the following statements holds true regarding the equilibrium constant (Kp) and degree of dissociation (α):

(a) Neither Kp nor α changes
(b) Both Kp and α change
(c) Kp changes, but α does not change
(d) Kp does not change, but α changes

9. The equilibrium constants Kp1 and Kp2 for the reactions X ⇌ 2Y and Z ⇌ P + Q, respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z is equal, then the ratio of total pressures at these equilibria are:

(a) 1 : 36
(b) 1 : 1
(c) 1 : 3
(d) 1 : 9

10. When N2O5 is heated at temp. T, it dissociates as N2O5 ⇌ N2O3 + O2 Kc = 2.5. At the same time, N2O3 also decomposes as N2O3 ⇌ N2O + O2. If initially 4.0 moles of N2O5 are taken in 1.0 litre flask and allowed to attain equilibrium, the concentration of O2 was found to be 2.5 M. Equilibrium concentration of N2O is

(a) 1.0
(b) 1.5
(c) 2.166
(d) 0.334

11. If we know the equilibrium constant for a particular reaction, we can calculate the concentrations in the equilibrium mixture from the initial concentrations. Commonly only the initial concentration of reactants is given.” In a study of equilibrium

H2 (g) + I2 (g) ⇌ 2HI (g)

1 mol of H2 and 3 moles of I2 gave rise at equilibrium to x moles of HI. The addition of a further 2 moles of H2 gave an additional x moles of HI. What is x?

(a) 0.5
(b) 1
(c) 1.5
(d) None of these

12. The conditions favorable for the formation of SO3 are:

2SO2 (g) + O2 (g) ⇌ 2SO3 (g) ; ΔH° = – 198 kJ

(a) low temperature, high pressure
(b) any value of T and P
(c) low temperature and low pressure
(d) high temperature and high pressure

13. The equilibrium SO2Cl2 (g) ⇌ SO2 (g) + Cl2 (g) is attained at 25°C in a closed container and an inert gas, helium is introduced at constant pressure. Which of the following statements is/are correct?

(a) concentrations of SO2, Cl2 and SO2Cl2 do not change
(b) more chlorine is formed
(c) concentration of SO2 is reduced
(d) more SO2Cl2 is formed

14. Pure ammonia is placed in a vessel at a temperature where its dissociation constant (α) is appreciable. At equilibrium, The true statement is N2 +3H2 ⇌ 2NH3

(a) Kp does not change with pressure
(b) α does not change with pressure
(c) the concentration of NH3 does not change with pressure
(d) the concentration of hydrogen is less than that of nitrogen

15. An equilibrium mixture in a vessel of capacity 100 litres contains 1 mol N2, 2 mol O2 and 3 mol NO. A number of moles of O2 to be added so that at new equilibrium the conc. of NO is found to be 0.04 mol/lit.

(a) (101/18)
(b) (101/9)
(c) (202/9)
(d) None of these