Which one of the following is an incorrect statement for physisorption ?

Options

A. it is a reversible process
B. It requries less heat of adsoption
C. it requires activation energy
D. It takes place at low temperature

Answer

To determine which statement about physisorption is incorrect, let's analyze each option step by step.

### Step 1: Analyze Option A
**Statement:** It is a reversible process.
**Explanation:** Physisorption involves weak Van der Waals forces between the adsorbate and the adsorbent. Because these forces are weak, the adsorption can easily be reversed. Therefore, this statement is **correct**.

### Step 2: Analyze Option B
**Statement:** It requires less heat of adsorption.
**Explanation:** Physisorption involves weak interactions, which means it requires less energy to break these interactions compared to chemisorption. Thus, this statement is also **correct**.

### Step 3: Analyze Option C
**Statement:** It requires activation energy.
**Explanation:** Physisorption does not require activation energy because it involves physical adsorption through weak forces, unlike chemisorption, which involves breaking and forming chemical bonds that require energy. Therefore, this statement is **incorrect**.

### Step 4: Analyze Option D
**Statement:** It takes place at low temperature.
**Explanation:** Physisorption is favored at lower temperatures because higher temperatures increase the kinetic energy of molecules, which can reduce the extent of adsorption. Therefore, this statement is **correct**.

### Conclusion
The incorrect statement regarding physisorption is **Option C: It requires activation energy**.

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