Question

If δh = -70.0 kj and δs = -0.500 kj/k , the reaction is spontaneous below a certain temperature. calculate that temperature. express your answer numerically in kelvins.

Answer 1

Answer is: temperature must be less than 140 K.
Gibbs free energy (G) determines if reaction will proceed spontaneously. If the value of G is a negative, the reaction is spontaneous. ΔG = ΔH - T·ΔS.
ΔH = -70.00 kJ.
ΔS = -0.500 kJ/K.
-70 kJ = T · (-0.5 kJ/K).
T = -70.00 kJ ÷ (-0.500 kJ/K).
T = 140 K.