The following drawing is a representation of a reaction of the type A → B,where different shaded spheres represent different molecular structures.For this reaction ΔH° = +45 kJ.This reaction is likely to be

Question

Quizplus · Accepted Answer

The positive value of ΔH° indicates an endothermic reaction. The reaction would be non-spontaneous at all temperatures if ΔS° were negative (since ΔG° = ΔH° - TΔS°, where T is temperature in kelvin), but we don't know the value of ΔS°. However, we do know that the reaction is more likely to be non-spontaneous at lower temperatures, since at low temperatures the entropic factor dominates the enthalpic factor. At high temperatures, the enthalpic factor dominates and the reaction becomes more spontaneous. Therefore, the most likely scenario is that the reaction is non-spontaneous at low temperatures and spontaneous at high temperatures.

The Following Drawing Is a Representation of a Reaction of the Type