What is the voltage of an electrolytic cell with copper and magnesium

electrodes?

A. 2.71 V

B. - 2.71 V

C. 2.03 V

D. - 2.03 V

A. 2.71 V

Explanation:

The standard reduction potential, E° of the metals are as follows:

Mg²⁺ + 2e⁻ ⇌ Mg; E° = - 2.372

Cu²⁺ + 2e⁻ ⇌ Cu; E° = + 0.337

Since magnesium has the the lower E°, it will serve as the anode in the electrolytic cell while copper will serve as the cathode.

At the anode; Mg ⇌ Mg²⁺ + 2e⁻, E° = - 2.372

At the cathode; Cu²⁺ + 2e⁻ ⇌ Cu, E° = + 0.337

EMF of the cell = E° cathode - E° anode = 0.337 - (-2.372) = 2.71 V

Therefore, EMF of the cell is 2.71 V