Question

A particular reaction at ${27}^{o}C$ for which $\Delta H>0$ and $\Delta S>0$ is found to be non-spontaneous. The reaction may proceed spontaneously if:

• A. the temperature is decreased
• B. the temperature is kept constant
• C. the temperature is increased
• D. it is carried in open vessel at ${27}^{o}C$

Answer 1

The correct option is C the temperature is increased

Gibb's energy equation: $\Delta G=\Delta H-T\Delta S$

For a spontaneous reaction, $\Delta G$ should be less than zero.

Therefore, if $\Delta H>0$ and $\Delta S>0$, the $T\Delta S$ term should be higher than $\Delta H$ for a spontaneous reaction. So, the temperature should be increased to make the reaction spontaneous.