Assertion :- Catalyst change Gibbs free energy of system.
Reason :- Catalyst changes preexponential factor of a chemical reaction.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Catalysts change Gibbs free energy of the system."
- **Analysis**: This statement is **incorrect**. Catalysts do not change the Gibbs free energy (ΔG) of the reactants or products in a chemical reaction. They only provide an alternative pathway with a lower activation energy for the reaction to occur.

2. **Understanding the Reason**:
- The reason states that "Catalysts change the pre-exponential factor of a chemical reaction."
- **Analysis**: This statement is also **incorrect**. The pre-exponential factor (A) in the Arrhenius equation (k = A * e^(-Ea/RT)) is not significantly altered by the presence of a catalyst. A catalyst primarily affects the activation energy (Ea), but not the pre-exponential factor.

3. **Conclusion**:
- Since both the assertion and the reason are incorrect, we conclude that the correct answer is that both statements are false.

### Final Answer:
Both the assertion and the reason are false.

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