In a reversible reaction a catalyst :-

Options

A. Increases the rate of forward reaction only
B. Increases the rate of the backward reaction
C. Increases the rate of forward reaction and decreases that of the forward reaction
D. Increases the rate of forward and backward reaction equally

Answer

**Step-by-Step Solution:**

1. **Understanding Reversible Reactions:**
- A reversible reaction is one where the products can be converted back into the reactants. This means that both the forward and backward reactions can occur.

2. **Role of a Catalyst:**
- A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It does this by providing an alternative pathway with a lower activation energy.

3. **Effect of a Catalyst in Reversible Reactions:**
- In a reversible reaction, a catalyst affects both the forward and backward reactions equally. This means that it increases the rate of the forward reaction and the rate of the backward reaction to the same extent.

4. **Evaluating the Options:**
- Given the options:
- A) Increases the rate of forward reaction only - **Incorrect** (as it affects both).
- B) Increases the rate of backward reaction only - **Incorrect** (as it affects both).
- C) Forward reaction decreases - **Incorrect** (it does not decrease).
- D) Increases the rate of both forward and backward reactions equally - **Correct**.

5. **Conclusion:**
- The correct answer is option D, as a catalyst increases the rate of both the forward and backward reactions equally in a reversible reaction.

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