Question

For a particular reversible reaction at temperature $T,\Delta H$ and $\Delta S$ were found to be both $+ve$. lf $T_e$ is the temperature at equilibrium, the reaction would be spontaneous when:

• A. $T_e>T$
• B. $T>T_e$
• C. $T_e$ is 5 times $T$
• D. $T=T_e$

Answer 1

The correct option is B $T>T_e$

Wew know,

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

At equilibrium,

$\Delta G=0$

$\Rightarrow 0=\Delta H-T\Delta S$

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

$T>T_e$