Question

Which of the following relations represents the correct relation between standard electrode potential and equilibrium constant?

I. \(\log K = \frac{n F E^\circ}{2.303 R T}\)

II. \(K = e^{\frac{n F E^\circ}{R T}}\)

III. \(\log K = -\frac{n F E^\circ}{2.303 R T}\)

IV. \(\log K = 0.4342 \frac{n F E^\circ}{R T}\)

Choose the correct statements.

• A. I, II and III are correct
• B. II and III are correct
• C. I, II and IV are correct
• D. I and IV are correct

Hint:

Use \(\ln K = \frac{n F E^\circ}{R T}\) and convert to base-10 carefully.

Answer 1

The Correct Option is D

Step 1: Relation between equilibrium constant and standard emf:
\[ \Delta G^\circ = -n F E^\circ = -R T \ln K \]
Step 2:
\[ \ln K = \frac{n F E^\circ}{R T} \]
Step 3:
\[ \log K = \frac{n F E^\circ}{2.303 R T} = 0.4342 \frac{n F E^\circ}{R T} \]
Thus statements I and IV are correct.