For a given reaction,ΔH = + 29.9 kJ/mol and ΔS = + 57.0 J/Kmol.The reaction is spontaneous ________.Assume that ΔH and ΔS do not vary with temperature.

Question

Quizplus · Accepted Answer

This is a question related to the Gibbs free energy equation, ΔG = ΔH - TΔS. For a reaction to be spontaneous, ΔG must be negative. At a constant temperature, if ΔH is positive and ΔS is positive, then the reaction will be spontaneous only at temperatures higher than ΔH/ΔS. In this case, ΔH/ΔS = (29,900 J/mol) / (57.0 J/Kmol) = 523 K. Therefore, the reaction is spontaneous at temperatures higher than 523 K, which corresponds to choice B.

For a Given Reaction,ΔH = + 29