Which of the following reaction characteristics change on addition of a catalyst to a reaction at constant temperature ?
(i) Activation energy ltbr. (ii) Equilibrium constant
(iii ) Gibbs enregy change
(iv ) enthylpy change of reaction

Options

A. (i) only
B. (iii) only
C. (i) and (ii) only
D. All of these

Explanation

To determine which reaction characteristics change upon the addition of a catalyst at constant temperature, we need to analyze each option provided in the question:

### Step-by-Step Solution:

1. **Understanding Catalysts**: 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 (Ea) required for the reaction to proceed.

2. **Analyzing Activation Energy (i)**:
- When a catalyst is added, it provides an alternative pathway for the reaction with a lower activation energy.
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