Given an example where physisorption changes to chemisorption with rise in temperature. Explain the reason for change.

Explanation

### Step-by-Step Solution:

1. **Understanding Physisorption and Chemisorption**:
- Physisorption is a type of adsorption that involves weak van der Waals forces. It is generally reversible and occurs at lower temperatures.
- Chemisorption, on the other hand, involves the formation of strong chemical bonds between the adsorbate and the surface of the adsorbent. This process is usually irreversible and occurs at higher temperatures.

2. **Example of Physisorption to Chemisorption**:
- A classic example is the adsorption of hydrogen gas (H₂) on finely divided nickel (Ni). At lower temperatures, hydrogen molecules are weakly adsorbed on the nickel surface through physisorption.
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