Question

Endothermic reactions, having $\Delta S=+ve$ may be spontaneous if:

• A. $\Delta H>T\Delta S$
• B. $\Delta H<T\Delta S$
• C. $\Delta H=T\Delta S$
• D. $T$ is very high

Answer 1

Answer: (B), (D)

$T$ is very high
$\Delta H<T\Delta S$

$\Delta G=\Delta H-T\Delta S$

For a spontaneous process, $\Delta G$ must be negative. When $\Delta H=+ve$ or endothermic then to make $\Delta G=-ve$, temperature should be high so that the term $T\Delta S$. becomes greater than the term $\Delta H$ and $\Delta H-T\Delta S$ becomes less than zero.