What is the effect of catalyst on the rate of reaction ?

Explanation

### Step-by-Step Solution:

1. **Definition of 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. **Types of Catalysts**:
- **Positive Catalyst**: This type of catalyst increases the rate of reaction. It lowers the activation energy required for the reaction to proceed.
- **Negative Catalyst (Inhibitor)**: This type of catalyst decreases the rate of reaction. It raises the activation energy required for the reaction to occur.

...