Question

A reaction, $A+B⟶C+D+q$ is found to have a positive entropy change. The reaction will be:

• A. possible at high temperature
• B. possible only at low temperature
• C. not possible at any temperature
• D. possible at any temperature

Answer 1

The correct option is D possible at any temperature

For a reaction to be spontaneous, $\Delta G$ should be negative.

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

According to the question, for the given reaction,

$\Delta S=$ positive

$\Delta H=$ negative (since heat is evolved)

$\Rightarrow \Delta G=$ negative

Therefore, the reaction is spontaneous at any temperature.

Hence, the correct answer is option $\text{D}$.