Answer is: can become spontaneous at a temperature of 1670 K. ΔG = 21.5 kJ/mol. ΔH = 25 kJ/mol. ΔS = 15.0 J/mol·K = 0.015 kJ/mol·K. T = ? The change in
Gibbs free energy (ΔG), at constant temperature and pressure, is: ΔG=ΔH−TΔS.
ΔH is the change in enthalpy.
ΔS is change in entropy.
T is temperature of the system.
When ΔG is negative, a reaction (occurs
without the addition of external energy) will be spontaneous (exergonic). TΔS > ΔH. T = ΔH ÷ ΔS. T = 25.0 kJ/mol ÷ 0.015 J/K·mol. T = 1670 K.
