Question

question 22 of 27
what are the signs of the enthalpy (δh) and entropy (δs) of a reaction that is always spontaneous?
a. -δh,+δs
b. +δh,-δs
c. -δh,-δs
d. +δh,+δs

Explanation:

The Gibbs - free energy change is given by $\Delta G=\Delta H - T\Delta S$. A reaction is spontaneous when $\Delta G<0$. For a reaction to be always spontaneous, $\Delta H$ should be negative (exothermic) and $\Delta S$ should be positive (increase in disorder). When $\Delta H<0$ and $\Delta S > 0$, then $\Delta G=\Delta H - T\Delta S<0$ at all temperatures.

Answer:

A. -$\Delta H$, +$\Delta S$