Question

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

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

Answer 1

Answer: (C)

$T>T_e$

For a particular reversible reaction at T temperature

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

When $\Delta H$, $S$ is positive

$\Delta G=+\Delta H-T.(+\Delta S)$

For spontaneous process, $\Delta G$ must be negative, it is possible only at hight temperature.

That mean $T>T_e$