Law Of Equilibrium And Equilibrium Constant MCQs

41. The equilibrium constant for the dissociation of water (Kw) at 25°C is:

• A) ( 1 \times 10^{-7} )
• B) ( 1 \times 10^{-14} )
• C)1.0
• D) 14.0
• Answer: B

42. For the reaction ( H_2(g) + I_2(g) \rightleftharpoons 2HI(g) ), if Kc = 50 at 500°C, it indicates:

• A) Reactants are favored
• B) Products are favored
• C) Equilibrium is not reached
• D) Both are equally favored
• Answer: B

43. At equilibrium, which statement is true?

• A) Concentration of reactants = concentration of products
• B) Forward and reverse reaction rates are equal
• C) Kc is zero
• D) Kc equals 1 always
• Answer: B

44. The equilibrium constant expression for ( CO + 2H_2 \rightleftharpoons CH_3OH ) is:

• A) ( K_c = \frac{[CO][H_2]^2}{[CH_3OH]} )
• B) ( K_c = \frac{[CH_3OH]}{[CO][H_2]^2} )
• C) ( K_c = [CO][H_2]^2 \times [CH_3OH] )
• D) None of these
• Answer: B

45. In exothermic reactions, decreasing temperature will:

• A) Shift equilibrium to the right
• B) Shift equilibrium to the left
• C) Have no effect
• D) Increase activation energy
• Answer: A

46. Which does not affect equilibrium position?

• A) Catalyst
• B) Temperature
• C) Pressure
• D) Concentration
• Answer: A

47. The law of chemical equilibrium is also known as:

• A) Law of mass action
• B) Le Chatelier’s Principle
• C) Equilibrium quotient
• D) Dissociation law
• Answer: A

48. Kp and Kc are related for reactions involving:

• A) Gases only
• B) Solids only
• C) Liquids only
• D) Aqueous solutions
• Answer: A

49. Which value can indicate complete reaction?

• A) K = 1
• B) K > 1
• C) K << 1
• D) K approaching infinity
• Answer: D

50. A shift in equilibrium that minimizes change is called:

• A) Equilibrium principle
• B) Le Chatelier’s Principle
• C) Law of dilution
• D) Dissociation principle
• Answer: B