Question

Why do physisorption and chemisorption behave differently with rise in temperature?

Answer 1

In physisorption, adsorbent and adsorbate get attached through weak Vander Waals forces. With increase in temperature, this bond becomes weaker and the amount of adsorbate decreases.

But in chemisorption, chemical bond formation occurs between adsorbent and adsorbate.

This requires a certain amount of activation energy which is achieved by increasing the temperature. Thus, the rate of chemisorption becomes faster with the increase in temperature.