Question

Account for the following:

The extent of physical adsorption decreases with rise in temperature.

Answer 1

The extent of physical adsorption decreases with rise in temperature because physical adsorption is an exothermic process involving weak van der Waals forces. Increasing temperature provides energy that overcomes these weak forces, causing adsorbed molecules to desorb. Thus, higher temperatures reduce the attraction between the gas molecules and the adsorbent surface, leading to decreased adsorption. This is why physical adsorption diminishes continuously as temperature rises.