What does Gibbs free energy predict? A. It predicts what the rate of the reaction will be.
B. It predicts how high the activation energy is.
C. It predicts if entropy will increase or decrease.
D. It predicts whether or not a reaction will be spontaneous.

D. It predicts whether or not a reaction will be spontaneous.

Explanation:

What does Gibbs free energy (ΔG) predict? .

A. It predicts what the rate of the reaction will be. NO. ΔG is a thermodynamical parameter and it is not related to the kinetics of the reaction.

B. It predicts how high the activation energy is. NO. ΔG is a thermodynamical parameter and it is not related to the kinetics of the reaction.

C. It predicts if entropy will increase or decrease. NO. ΔG depends on the entropy but not the other way around.

D. It predicts whether or not a reaction will be spontaneous. YES. If ΔG < 0 the reaction is spontaneous and if ΔG > 0 the reaction is not spontaneous.

the answer is symmetrical : )