The nature of forces operating between the adsorbate and the adsorbent in the adsorption occuring at high temperature is 

Options

A. vander Waals forces
B. chemical forces
C. gravitational forces
D. fermi forces

Answer

To determine the nature of forces operating between the adsorbate and the adsorbent during adsorption at high temperatures, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Adsorption**:
- Adsorption is the process where molecules (adsorbate) adhere to the surface of a solid or liquid (adsorbent).

2. **Temperature Influence**:
- The question specifies that the adsorption occurs at high temperatures. Temperature can significantly affect the nature of interactions between the adsorbate and adsorbent.

3. **Types of Forces in Adsorption**:
- There are generally two types of forces involved in adsorption:
- **Physical Forces (Van der Waals Forces)**: These are weaker forces that occur due to temporary dipoles and are more prevalent at lower temperatures.
- **Chemical Forces (Chemical Bonds)**: These are stronger interactions that involve the formation of chemical bonds between the adsorbate and adsorbent.

4. **High Temperature Effects**:
- At high temperatures, the kinetic energy of molecules increases, which can lead to more significant interactions.
- In this scenario, the adsorption process is more likely to involve chemical forces rather than physical forces, as the energy provided can facilitate the formation of stronger bonds.

5. **Conclusion**:
- Therefore, the nature of the forces operating between the adsorbate and the adsorbent during adsorption at high temperatures is primarily due to **chemical forces**.

### Final Answer:
The nature of forces operating between the adsorbate and the adsorbent in adsorption occurring at high temperature is **chemical forces**.

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