At what temperatures will a reaction be spontaneous if ΔH° = +62.4 kJ and ΔS° = +301 J/K?

Question

Quizplus · Accepted Answer

For a reaction to be spontaneous, the Gibbs free energy change (ΔG°) must be negative. ΔG° can be calculated using the equation ΔG° = ΔH° - TΔS°, where ΔH° is the change in enthalpy, T is the temperature in Kelvin, and ΔS° is the change in entropy. Given ΔH° = +62.4 kJ = +62400 J (to match units with ΔS°) and ΔS° = +301 J/K, we want ΔG° < 0. Rearranging the equation gives T > ΔH°/ΔS°. Plugging in the values gives T > 62400 J / 301 J/K = 207.31 K. Therefore, the reaction will be spontaneous at temperatures above 207 K.

At What Temperatures Will a Reaction Be Spontaneous If ΔH°