31. What happens to the equilibrium constant (KcK_cKc​) when the temperature of an exothermic reaction is increased?

a) Increases
b) Decreases
c) Remains constant
d) Becomes zero
Answer: b) Decreases

32. Which of the following statements is true about the equilibrium constant?

a) It changes with pressure
b) It is independent of temperature
c) It depends on the initial concentrations
d) It changes with temperature
Answer: d) It changes with temperature

33. In the reaction PCl5(g)⇌PCl3(g)+Cl2(g)PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)PCl5​(g)⇌PCl3​(g)+Cl2​(g), what is the effect of increasing pressure?

a) Equilibrium shifts to the right
b) Equilibrium shifts to the left
c) No effect on equilibrium position
d) Decreases the equilibrium constant
Answer: b) Equilibrium shifts to the left

34. What is the term for a reaction that occurs in both forward and reverse directions?

a) Reversible reaction
b) Irreversible reaction
c) Spontaneous reaction
d) Non-spontaneous reaction
Answer: a) Reversible reaction

35. Which of the following conditions does NOT affect the equilibrium constant?

a) Temperature
b) Catalyst presence
c) Nature of reactants
d) Initial concentrations
Answer: d) Initial concentrations

36. What is the equilibrium constant expression for the reaction H2(g)+I2(g)⇌2HI(g)H_2(g) + I_2(g) \rightleftharpoons 2HI(g)H2​(g)+I2​(g)⇌2HI(g)?

a) [HI]2/[H2][I2][HI]^2/[H_2][I_2][HI]2/[H2​][I2​]
b) [H2][I2]/[HI]2[H_2][I_2]/[HI]^2[H2​][I2​]/[HI]2
c) [HI]/[H2][I2][HI]/[H_2][I_2][HI]/[H2​][I2​]
d) [H2]2[I2]2/[HI][H_2]^2[I_2]^2/[HI][H2​]2[I2​]2/[HI]
Answer: a) [HI]2/[H2][I2][HI]^2/[H_2][I_2][HI]2/[H2​][I2​]

37. What is the effect of increasing the concentration of a product in a system at equilibrium?

a) Shifts equilibrium to the right
b) Shifts equilibrium to the left
c) No change in equilibrium position
d) Increases the equilibrium constant
Answer: b) Shifts equilibrium to the left

38. In the reaction 2NO(g)+O2(g)⇌2NO2(g)2NO(g) + O_2(g) \rightleftharpoons 2NO_2(g)2NO(g)+O2​(g)⇌2NO2​(g), what happens when the concentration of O2O_2O2​ is decreased?

a) Equilibrium shifts to the right
b) Equilibrium shifts to the left
c) No effect on equilibrium position
d) Reaction rate increases
Answer: b) Equilibrium shifts to the left

39. What is the effect of adding an inert gas to a reaction at equilibrium in a closed container?

a) Shifts equilibrium to the right
b) Shifts equilibrium to the left
c) No effect on equilibrium position
d) Changes the equilibrium constant
Answer: c) No effect on equilibrium position

40. Which of the following statements is true about a system at equilibrium?

a) The reaction quotient (QQQ) equals the equilibrium constant (KKK)
b) The forward reaction rate is greater than the reverse reaction rate
c) The concentrations of reactants are higher than those of products
d) No reactions are occurring
Answer: a) The reaction quotient (QQQ) equals the equilibrium constant (KKK)