Question

An exothermic reaction and a endothermic reaction may not be always thermodynamically spontaneous.Jutsify.

Answer 1

Effects of T on spontaneity of a process: ΔG = ΔH – TΔS.
(i) For endothermic process - It may be non spontaneous at law temp.85
(ii)For exothermic process - It may be non spontaneous at high temp. and spontaneous at law temp.

Exothermic reaction is not always spontaneous. If S = +ve and TΔS> ΔH. The process will be non spontaneous even it. It is endothermic.

So, endothermic and exothermic reactions are not always thermodynamically spontaneous.