Which of the following best characterizes the free energy change ΔG for an endothermic reaction under physiological conditions? A. The sign of ΔG is positive

B. The sign of ΔG is zero

C. The sign of ΔG is negative

D. The sign of ΔG cannot be determined without more information

D

Explanation:

Whether endothermic or exothermic, for a reaction to be spontaneous, ∆G must be negative.

∆G=∆H-T∆S.

The values of temperature and entropy change can be determined when the values of enthalpy, entropy and temperature are known. When ∆G is zero, the reaction has attained equilibrium.