Question

Which of the following statements is correct for a reversible process in a state of equilibrium?

<!--td {border: 1px solid #cccccc;}br {mso-data-placement:same-cell;}--> AIPMT 2015

• A. $\Delta G^o=2.303RT\log K$
• B. $\Delta G^o=-2.303RT\log K$
• C. $\Delta G=2.303RT\log K$
• D. $\Delta G=-2.303RT\log K$

Answer 1

The correct option is B $\Delta G^o=-2.303RT\log K$

The relationship between the Gibbs free energy change $\Delta G$, the standard Gibbs free energy change $\Delta G^o$ and the equilibrium constant $K$ is
$\Delta G=\Delta G^o+2.303RT\log K$
For a reversible process in a state of equilibrium $\Delta G=0$
Hence,
$\Delta G^o=-2.303RT\log K$