Question

What will be the free energy under the following conditions:

I. If both delta S and H are (+)
II. If both delta S and H are (-)
III. If delta S is (-) and H is (+)
IV. If delta S is (+) and H is (-)
A. I only
B. II only
C. III only
D. IV only

Answer 1

The sign of the change in free energy, delta G, is determined by the signs of the enthalpy change, delta H, and the entropy change, delta S. Choices A, B, C, and D correspond to the different scenarios.

Step-by-step explanation:

The sign of the change in free energy, delta G, is determined by the signs of the enthalpy change, delta H, and the entropy change, delta S, according to these four scenarios:

1. Both delta S and delta H are positive: the change in free energy is negative and the reaction is spontaneous. This corresponds to option I. Only choice A satisfies this condition.
2. Both delta S and delta H are negative: the change in free energy is positive and the reaction is nonspontaneous. This corresponds to option II. Only choice B satisfies this condition.
3. Delta S is negative and delta H is positive: the change in free energy is positive and the reaction is nonspontaneous. This corresponds to option III. Only choice C satisfies this condition.
4. Delta S is positive and delta H is negative: the change in free energy is negative and the reaction is spontaneous. This corresponds to option IV. Only choice D satisfies this condition.