Question

In a reaction $P + Q \to R + S$, there is no change in entropy. Enthalpy change for the reaction $(\Delta H)$ is $12\, kJ\, mol^{-1}$. Under what conditions, reaction will have negative value of free energy change?

• A. If $\Delta H$ is positive
• B. If $\Delta H$ is negative
• C. If $\Delta H$ is $24 \,kJ\, mol^{-1}$
• D. If temperature of reaction is high

Answer 1

Answer: (B)

$\Delta G = \Delta H-T\Delta S, \Delta S = 0$ or $T\Delta S = 0$
$\Delta G = \Delta H$