Question

adsorption of gases on solid surface is generally exothermic because

Answer 1

This causes a decrease in the surface energy of the adsorbent. Therefore, adsorption is always exothermic. (ii)ΔH of adsorption is always negative. When a gas is adsorbed on a solid surface, its movement is restricted leading to a decrease in the entropy of the gas i.e., ΔS is negative.