Question

Which one of the following statements is correct in a reversible reaction?
A catalyst -
A. Increases the rate of forward reaction
B. Decreases the rate of forward reaction
C. Increases the rate of backward and forward reaction
D. Alters the equilibrium constant of the reaction

Answer 1

Hint: A catalyst is very useful in chemical reactions. It fastens a reaction by facilitating an alternate pathway with less activation energy. Some catalysts are manganese dioxide, platinum, palladium, nickel, etc.

Complete Step by Step Answer:
Let's understand what happens with the catalyst addition to a system. The role of the catalyst is to speed up both the forward and the backward reactions. Thus, it helps to achieve the equilibrium state early. But the concentration at equilibrium is not changed, that is, the equilibrium constant is not changed.
Let's discuss the options one by one.
Option A says that only the forward reaction's rate increases which is false. Therefore, A is wrong.
Option B says that the forward reaction's rate decreases which is false. Therefore, B is wrong.
Option D says that catalysts alter the equilibrium constant which is not true. Therefore, D is wrong.
Option C says both the rates of both the reactions, that is, forward and backward reaction increases, which is true. Therefore, C is right.
Therefore, option C is right.

Note: Catalysts have no impact on the thermodynamic parameters such as Gibbs free energy. They are also not consumed in the reaction. They are separated as the reaction comes to an end. The equilibrium constant is also not affected by the catalysts.