For the reaction A + B → C + D, ΔH° = +40 kJ and ΔS° = +50 J/K. Therefore, the reaction under standard conditions is

Question

Quizplus · Accepted Answer

The Gibbs free energy change under standard conditions can be calculated using the equation ΔG° = ΔH° - TΔS°, where T is the temperature in Kelvin. For this reaction, ΔH° is positive and ΔS° is positive, so we know that spontaneity depends on temperature. At low temperatures, the TΔS° term will be small and the reaction will be nonspontaneous. At high temperatures, the TΔS° term will become large enough to overcome the positive ΔH° term, making the reaction spontaneous. Therefore, the reaction will only be spontaneous at temperatures greater than 800 K.

For the Reaction a + B → C + D