Question

A cell is prepared by dipping a chromium rod in 1M Cr₂(SO₄)₃ solution and an iron rod in 1M FeSO₄ solution. The standard reduction potentials of Chromium and Iron electrodes are -0.75 V and -0.45 V respectively. What will be the standard EMF of the cell?

• A. - 0.30 V
• B. +0.47 V
• C. -0.47 V
• D. +0.30 V

Answer 1

The correct option is D

+0.30 V

The standard EMF of the cell,

E_cell = E_cathode - E_anode

So,

E_cell = -0.45 - (-0.75) = 0.75-0.45 = +0.30 V.