Calculate the cell potential of the electrolytic cell

Question

Calculate the cell potential of the electrolytic cell, identify the anode and the cathode and write the

balanced equation for the overall cell reaction that occurs according to the reaction shown below.

Al(s) + Mn²⁺(aq) → Mn(s) + Al³⁺(aq)

Answer 1

Al(s) + Mn²⁺(aq) → Mn(s) + Al³⁺(aq)

Looking at the above equation, we see that Al(s) is oxidized to Al³⁺ and Mn²⁺ is reduced to Mn(s)

From a table of standard reduction potentials, I find the following:

Al³⁺ + 3e- ==> Al(s) Eº = -1.66 V (anode)

Mn²⁺ + 2e- ==> Mn(s) Eº= -1.18 V (cathode)

Eºcell = -1.18 - (-1.66) = 0.48 V = cell potential

Anode = Al

Cathode = Mn

Overall cell reaction:

2Al(s) + 3Mn²⁺(aq) ==> 2Al³⁺(aq) + 3Mn(s)