Question

Why the spontaneos adsobtion of the gas on the solid surface is an exothermic process?

Answer 1

$\huge\mathfrak\green{Hello,}$

$\huge\underline{Answer:}$

Adsorption is always exothermic. ... 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. Now for a process to be spontaneous, ΔG should be negative.

$Hope\:it\:helps!$

Regards,

$\huge\mathfrak\purple{Aaravxxx}$