Which one of the following statements is correct ? In a reversible reaction, catalyst

Options

A. increases the rate of the forward reaction
B. decreases the rate of the reverse reaction
C. increases the rate of the forward and reverse reactions
D. alters the equillibrium constant of the reaction.

Answer

To solve the question regarding the role of a catalyst in a reversible reaction, we can follow these steps:

### Step 1: Understand the Role of a Catalyst
A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It achieves this by lowering the activation energy required for the reaction to occur.

**Hint:** Remember that a catalyst does not change the overall energy of the reactants and products; it only affects the pathway of the reaction.

### Step 2: Analyze the Reversible Reaction
In a reversible reaction, both the forward and reverse reactions occur. A catalyst will affect both of these reactions equally.

**Hint:** Think about how a catalyst interacts with the reactants in both directions of the reaction.

### Step 3: Evaluate Each Option
Now, let's evaluate the provided options one by one:

1. **Increases the rate of forward reaction**: This is true, but it does not encompass the full effect of the catalyst.

2. **Decreases the rate of reverse reaction**: This is incorrect. A catalyst does not decrease the rate of any reaction; it increases the rate of both.

3. **Increases the rate of forward and reverse reaction**: This is correct because a catalyst speeds up both the forward and reverse reactions equally.

4. **Alters the equilibrium constant of the reaction**: This is incorrect. A catalyst does not change the equilibrium constant; it only helps the system reach equilibrium faster.

**Hint:** When evaluating options, consider the complete effect of the catalyst on both directions of the reaction.

### Step 4: Conclusion
Based on the analysis, the correct statement regarding the role of a catalyst in a reversible reaction is that it increases the rate of both the forward and reverse reactions.

**Final Answer:** The correct option is **C**: A catalyst increases the rate of forward and reverse reactions.