Question

what does a positive value of $\delta g^0$ mean for a reaction?
a. the reaction is spontaneous if $\delta s > 0$.
b. the reaction is spontaneous.
c. the reaction is nonspontaneous.
d. the reaction is spontaneous if $\delta s < 0$.

Explanation:

The Gibbs free energy change ($\Delta G^0$) determines reaction spontaneity. A negative $\Delta G^0$ means spontaneous (releases free energy), and a positive $\Delta G^0$ means non - spontaneous (requires energy input). Option A: $\Delta S>0$ alone doesn't make a reaction with positive $\Delta G^0$ spontaneous. Option B: A positive $\Delta G^0$ means the reaction is not spontaneous. Option D: $\Delta S < 0$ would make a reaction with positive $\Delta G^0$ even less likely to be spontaneous. So the correct option is C.

Answer:

C. The reaction is nonspontaneous.