Give reasons for the following observations:
Physisorption decreases with increase in temperature.
Why does physisorption decrease with the increase of temperature?
Physisorption is exothermic in nature:
Solid + Gas ⇌ Gas/Solid + Heat
(Adsobent) (Adsobate) (Gas adsorbed on solid)
In accordance with Le Chatelier’s principle, physisorption decreases with an increase in temperature. Because the equilibrium will shift in the backward direction, gas will be released from the adsorbed surface.