Question

The standard reaction Gibbs energy for a chemical reaction at an absolute temperature T is given by ΔG⁰ = A − BT where A and Bare non-zero constants. Which of the following is true about this reaction?

Options

• Exothermic if B < 0.

• Endothermic if A > 0.

• Endothermic if A < 0 and B > 0.

• Exothermic if A > 0 and B < 0.

Answer 1

Endothermic if A > 0.

Explanation:

ΔG⁰ = A − BT

A and B are non-zero constants.

∴ ΔG⁰ = ΔH⁰ − TΔS⁰ = A − BT

∴ Reaction will be endothermic if ΔH⁰ > 0.

Hence, A > 0