When metallic copper is shaken with a solution of a copper salt, the reaction proceeds. When equilibrium is established at 298 K, [Cu²⁺]/[Cu⁺]2 = 1.667 × 106 M–1. If the standard potential of the Cu²⁺ | Cu half-cell is +0.3376 V, what is the standard potential of Cu⁺| Cu half-cell? (Given : 2.303 RT/F = 0.06, log 2 = 0.3 , log 3 = 0.48)