AP EAPCET 08-Jul-2022 Shift 2 Paper

Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion. The correct reason for given assertion is as follows : When a gas is adsorbed on a solid surface, its movement is restricted. This leads to a decrease in the entropy of the gas i.e. ∆ S. is negative. Now, for a process to be spontaneous, ∆G should be negative.
We know that, ∆G=∆HH−T∆S
Now, ∆S is negative, ∆H has to be negative to make ∆G negative. Hence, adsorption is always exothermic.