In electrolytic refining of nickel (Ni), the anode is Cu-10 atom% Ni and the cathode is pure Ni. Assuming the Cu-Ni solution to be ideal, the absolute value of the minimum voltage (in mv) required for refining is.
Given, Faraday's constant = 96490 C mole^-1, Temperature = 300 K, R = 8.314 J. mol^-1. K^-1

A. 10

B. 15

C. 20

D. 30

Answer: Option D