Calculate Gibbs free energy when S = 131 J mol-1 and H = 155 kJ mol-1 at 25 C, stating whether or not the reaction is feasable.

First, make sure everything is in the correct units: H = 155 kJ mol-1 = 155000 J mol-1 S = 131 J mol-1 T = 25 C = 298K Then use the Gibbs equation to calculate the free energy: G = H - TS G = 155000-298*131 G = 115962 J mol-1 The reaction is not feasible at 25 C as G is positive, therefore temperature must be increased for the reaction to occur