An exothermic reaction with Δ S=-ve, is:

Question

An exothermic reaction with Δ S=-ve, is: (A) spontaneous at all temperatures (B) non-spontaneous at low temperatures (C) non-spontaneous at high temperatures (D) spontaneous at high temperatures

Tardigrade Admin · Accepted Answer

An exothermic reaction with Δ S=-ve, is spontaneous, when: Δ H>T. Δ S i.e., at low temperatures. Since from, Gibbs-Helmholtz equation. Δ G=Δ H-T.Δ G Δ G to be negative, Δ H>T. Δ S (if Δ H=- ve, Δ S=- ve ) Hence, reaction will be non-spontaneous at high temperatures.

Q. An exothermic reaction with ΔS=−ve, is:

spontaneous at all temperatures

non-spontaneous at low temperatures

non-spontaneous at high temperatures

spontaneous at high temperatures

An exothermic reaction with ΔS=−ve, is spontaneous, when: ΔH>T.ΔS i.e., at low temperatures. Since from, Gibbs-Helmholtz equation. ΔG=ΔH−T.ΔG ΔG to be negative, ΔH>T.ΔS (if ΔH=−ve, ΔS=−ve ) Hence, reaction will be non-spontaneous at high temperatures.

Q. An exothermic reaction with $Δ S = - v e,$ is: