A : A catalyst does not alter the equilibrium constant of a reaction
R : A catalyst does not alter the position of chemical equilibrium .

Options

A. If both Assertion & Reason are true and the reason in the corret explanation of the assertion, then mark
B. If both assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark
C. If Assertion is true statement but Reason is false then mark
D. If both Assertion and Reason are false statements , then mark

Answer

To solve the question regarding the assertion and reason about catalysts and equilibrium, we will analyze both statements step by step.

### Step 1: Understand the Assertion
The assertion states: "A catalyst does not alter the equilibrium constant of a reaction."

- **Explanation**: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It does this by lowering the activation energy required for the reaction to occur. However, it does not change the inherent energy levels of the reactants and products, meaning that the equilibrium constant (K) remains unchanged.

**Hint**: Recall that the equilibrium constant is determined by the energies of the reactants and products, not by the pathway taken to reach equilibrium.

### Step 2: Understand the Reason
The reason states: "A catalyst does not alter the position of chemical equilibrium."

- **Explanation**: The position of equilibrium refers to the concentrations of reactants and products at equilibrium. A catalyst speeds up both the forward and reverse reactions equally, allowing the system to reach equilibrium faster, but it does not change the concentrations of reactants and products at equilibrium.

**Hint**: Consider how a catalyst affects both the forward and reverse reactions equally, leading to no change in the final concentrations.

### Step 3: Evaluate the Truth of Each Statement
- **Truth of Assertion**: True. A catalyst does not alter the equilibrium constant.
- **Truth of Reason**: True. A catalyst does not change the position of equilibrium.

**Hint**: Verify if both statements are consistent with the principles of chemical kinetics and equilibrium.

### Step 4: Determine the Relationship Between Assertion and Reason
Since both the assertion and reason are true, we need to check if the reason correctly explains the assertion.

- The reason explains that a catalyst does not change the position of equilibrium, which is a direct consequence of the assertion that it does not alter the equilibrium constant.

**Hint**: Think about how the role of a catalyst in speeding up reactions relates to the concept of equilibrium.

### Conclusion
Both the assertion and reason are true, and the reason is the correct explanation for the assertion. Therefore, the answer is:

**Answer**: A (Both assertion and reason are true, and the reason is the correct explanation of the assertion).