Question

The correct relationship between free energy change in a reaction and the corresponding equilibrium constant $K$ is:

• A. $-\Delta G^{\circ }=RTinK$
• B. $\Delta G=RTinK$
• C. $-\Delta G=RTinK$
• D. $\Delta G^{\circ }=RTinK$

Answer 1

The correct option is A $-\Delta G^{\circ }=RTinK$

The equilibrium constant is related to the free energy change of the reaction by the expression:

$K=e^{(-\Delta G^o/RT)}$ or $lnK=-\Delta G^o/RT$

or $-\Delta G^o=RTlnK$ in which $T$ is the temperature in Kelvin and $R$ is the gas constant (1.986 cal/K mol)