How does temperature affect the spontaneity of a reaction?

Question

Wyatt Atkins · Accepted Answer

Spontaneity depends on the sign of #ΔG#.

Three scenarios are possible: The value of #ΔG# depends on temperature: #color(blue)(bar(ul(|color(white)(a/a)ΔG = ΔH - TΔScolor(white)(a/a)|)))" "# Now, we have four possible situations, depending on the signs of #ΔH# and #ΔS#: #bb(ΔHcolor(white)(m)ΔS color(white)(mmm)"High Temp."color(white)(mmmmmm)"Low Temp.")# #color(white)(l)+color(white)(ml)+ color(white)(m)ΔG -; "spontaneous"color(white)(mmm)ΔG +; "not spontaneous"# #color(white)(l)+color(white)(ml)- color(white)(m)ΔG +; "not spontaneous"color(white)(m)ΔG +; "not spontaneous"# #color(white)(l)-color(white)(ml)+ color(white)(m)ΔG -; "spontaneous"color(white)(mmm)ΔG -; "spontaneous"# #color(white)(l)-color(white)(ml)- color(white)(m)ΔG +; "not spontaneous"color(white)(m)ΔG -; "spontaneous"#

Wyatt Adkins · Answer

undefined Temperature influences reaction spontaneity by affecting the Gibbs free energy change. Higher temperatures generally favor spontaneity as they increase the likelihood of the reaction proceeding in the direction of lower Gibbs free energy.