Question

A spontaneous reaction is impossible if

• A. both Δ H and Δ S are negative
• B. both Δ H and Δ S are positive
• C. Δ H is negative and Δ S is positive
• D. Δ H is positive and Δ S is negative

Hint:

Δ H>0 and Δ S<0 ⟹ reaction is never spontaneous.

Answer 1

The Correct Option is D

For spontaneity, Δ G = Δ H - TΔ S < 0. When Δ H > 0 and Δ S < 0, Δ G is always positive.