Question

Which of the following relation(s) is/are correct for thermodynamic equilibrium constant?

• A. $\Delta G^o=-2.303RTlogK$
• B. $\Delta G=\Delta G^o+2.303RTlogQ$
• C. $E_{cell}^0=\frac{0.0591}{n}logK$
• D. $E=E^0-\frac{0.0591}{n}logQ$

Answer 1

Answer: (A), (B), (D)

The correct options are
A $\Delta G^o=-2.303RTlogK$
B $\Delta G=\Delta G^o+2.303RTlogQ$
D $E=E^0-\frac{0.0591}{n}logQ$

The relationship between the standard free energy change and the equilibrium constant is $\Delta G^o=-RTlnK=-2.303RTlogK$.
The relationship between the free energy change, standard free energy change and the reaction quotient is $\Delta G=\Delta G^o+RTlnQ=\Delta G^o+2.303RTlogQ$.
The relationship between the emf of cell, the standard emf of cell and the reaction quotient is $E=E^0-\frac{RT}{nF}lnQ=E^0-\frac{2.303RT}{nF}logQ$.
At 298 K, the expression becomes $E=E^0-\frac{0.0591}{n}logQ$.