Question

The relationship between $\Delta G^o$ of a reaction and its equilibrium constant is:

• A. $-\Delta G^{\circ }=\frac{RT}{Ink}$
• B. $\Delta G^{\circ }=\frac{RT}{Ink}$
• C. $\frac{RTInK}{\Delta G^{\circ }}=-1$
• D. $\Delta G^{\circ }=RTInK$

Answer 1

The correct option is A $-\Delta G^{\circ }=\frac{RT}{Ink}$

Relationship between $\Delta G$ and the reaction quotient $Q$:

$\Delta G$= $\Delta G^{\circ }+RT\ln Q$

where $\Delta G^{\circ }$indicates that all reactants and products are in their standard states. For gases at equilibrium (Q=K) and $\Delta G$ = 0 for a system at equilibrium. Therefore, we can describe the relationship between $\Delta G^{\circ }$ and K for gases as follows:

$\begin{array}{c}0=\Delta G^{\circ }+RT\ln K\\ \Delta G^{\circ }=-RT\ln K\\ -\Delta G^{\circ }=\frac{RT}{\ln K}\end{array}$

Hence, option $A$ is correct answer.