How are the reactions classified on the basis of rates of reactions ? Give examples.

Explanation

### Step-by-Step Solution:

1. **Classification of Reactions Based on Rates**:
Reactions can be classified into three main categories based on their rates: fast reactions, moderate reactions, and slow reactions.

2. **Fast Reactions**:
- **Definition**: Fast reactions, also known as instantaneous reactions, are those that occur in a very short amount of time.
- **Example**: A common example of a fast reaction is the burning of an active metal like sodium. When sodium reacts with oxygen, it burns rapidly, completing the reaction almost instantaneously.
...