Give one example each of a reversible and a irreversible reaction.

Explanation

To answer the question, we will provide one example each of a reversible and an irreversible reaction, along with a brief explanation of each.

### Step-by-Step Solution:

1. **Identify a Reversible Reaction**:
- A common example of a reversible reaction is the decomposition of phosphorus pentachloride (PCl5) in the gaseous state.
- The reaction can be represented as:
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...