Which of the following statements is not true?

Options

A. Both physisorption and chemisorption are exothermic
B. Physisorption takes place with decrease of free energy whereas the chemisorption occurs with increase of free energy
C. Physisorption requires low activation energy but the chemisorption requires high activation energy
D. The magnitude of chemisorption increases and that of physisorption decreases with rise in temperature

Explanation

To solve the question "Which of the following statements is not true?" regarding physisorption and chemisorption, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: Both physisorption and chemisorption are exothermic processes.**
- **Analysis:** This statement is true. Both processes release heat, meaning they have negative enthalpy changes (ΔH < 0). Physisorption involves weak Van der Waals forces, while chemisorption involves the formation of chemical bonds, both of which are exothermic.

2. **Statement 2: Physisorption takes place with a decrease of free energy whereas chemisorption occurs with an increase of free energy.**
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