A chemical reaction has catalyst X. Hence X

Options

A. Reduce enthalpy of the reaction
B. Dercreases rate constant of the reaction
C. increasees activation energy of the reaction
D. does not affect equilibrium constant of the reaction

Explanation

To solve the question regarding the effect of catalyst X on a chemical reaction, we will analyze each statement provided in the question.

### Step-by-Step Solution:

1. **Understanding 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 providing an alternative reaction pathway with a lower activation energy.

2. **Evaluating Each Statement**:
- **Statement 1: "X reduces the enthalpy of the reaction."**
- This statement is **incorrect**. A catalyst does not change the enthalpy of the reaction. The enthalpy change (ΔH) is a property of the reactants and products and remains the same regardless of the presence of a catalyst.

- **Statement 2: "X decreases the rate constant of the reaction."**
- This statement is also **incorrect**. A catalyst increases the rate constant of a reaction by lowering the activation energy, thus speeding up the reaction.

- **Statement 3: "X increases activation energy of the reaction."**
- This statement is **incorrect**. A catalyst decreases the activation energy, making it easier for the reaction to occur.

- **Statement 4: "X does not affect the equilibrium constant."**
- This statement is **correct**. A catalyst does not affect the position of equilibrium or the equilibrium constant (K). It only helps the system reach equilibrium faster.

3. **Conclusion**:
- The only correct statement regarding the effect of catalyst X on the chemical reaction is that it does not affect the equilibrium constant.

### Final Answer:
The correct option is: **X does not affect the equilibrium constant.**

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