In which of the following conditions a chemical reaction can not occur

Options

(a) ΔH and ΔS increase and TΔS > ΔH
(b) ΔH and ΔS decrease and ΔH > TΔS
(c) ΔH increases and ΔS increases
(d) ΔH decreases and ΔS increases

Correct Answer:

ΔH increases and ΔS increases

Explanation:

(i)When ΔH and ΔS increase, then , if TΔS > ΔH the reaction is spontaneous.
Therefore ΔG = ΔH – TΔS = -ve.
(ii)When ΔH and ΔS decrease,then if ΔH > TΔS. This makes ΔG is -ve and process is spontaneous.
(iii) If , ΔH increases and ΔS decreases, then ΔG is +ve and process is non-spontaneous.
(iv) If ΔH decrease and ΔS increases, then ΔG is -ve and process is spontaneous.