Question

Assertion(A): Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.

Reason(R): Entropy of the system increases with increase in temperature.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is not the correct explanation of A.
• C. A is true but R is false.
• D. Both A and R are false.

Answer 1

The correct option is B Both A and R are true but R is not the correct explanation of A.

$\Delta G=\Delta H-T\Delta S$
$\Delta H$ is +ve for endothermic process.

For spontaneous process $\Delta G<0$
$\therefore \Delta H-T\Delta S<0$
i.e $\Delta H<T\Delta S$
If we increase the temperature $\Delta H$ may become less than T$\Delta$S.
Entropy of the system also increases with increase in temperature but only slightly.

$\therefore$ Reason does not explain assertion.