Adsorption is multillayar in case of :

Options

A. physical adsorption
B. chemisoption
C. both (A) and (B)
D. none of these

Answer

To solve the question "Adsorption is multilayer in case of:", we will analyze the types of adsorption mentioned and determine which one allows for multilayer formation.

### Step-by-Step Solution:

1. **Understanding Adsorption**:
- Adsorption is the process where molecules from a gas or liquid adhere to a solid surface (adsorbent). There are two main types of adsorption: physical adsorption (physisorption) and chemical adsorption (chemisorption).

2. **Physical Adsorption (Physisorption)**:
- This type of adsorption occurs due to weak Van der Waals forces.
- Since these forces are relatively weak, multiple layers of adsorbate can accumulate on the adsorbent surface.
- Therefore, physical adsorption can lead to multilayer formation.

3. **Chemical Adsorption (Chemisorption)**:
- In chemisorption, the adsorbate forms strong chemical bonds with the adsorbent.
- This process typically results in the formation of a single layer (monolayer) because once the surface sites are occupied by adsorbate molecules, no further adsorption can occur without breaking the existing bonds.

4. **Conclusion**:
- Since multilayer adsorption is possible in physical adsorption due to the weak forces involved, while chemisorption only allows for a monolayer, the correct answer to the question is:
- **Physical adsorption**.

### Final Answer:
Adsorption is multilayer in case of **Physical Adsorption**.

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