CATHODIC PROTECTION

Resolved Question

Based of the standard reduction potentials provided below, which of the following metals could provide cathodic protection to keep iron metal from corroding?

(Select all that apply.)
Half-Reaction E° (V)

Ag+(aq) + e‾ → Ag(s) +0.80
Co2+(aq) + 2 e‾ → Co(s) -0.28
Cr3+(aq) + 3 e‾ → Cr(s) -0.74
Cu2+(aq) + 2 e‾ → Cu(s) +0.15
Fe2+(aq) + 2 e‾ → Fe(s) -0.44
Ni2+(aq) + 2 e‾ → Ni(s) -0.25
Mg2+(aq) + 2 e‾ → Mg(s) -2.37
Zn2+(aq) + 2 e‾ → Zn(s) -0.76

by joeyeehu...


Contributing In:
Chemistry
Best Answer - Chosen by Asker

For cathodic protection of iron from corroding, all you need is to find a metal which is more electropositive than iron. So, you have to choose the metals that have the standard reduction potentials which are more negative than that of iron.

Since E(Fe2+/Fe) = - 0.44 v, Cr(-0.74), Mg(-2.37) and Zn(-0.76) can be used.
Of course, Mg is the best and most efficient as it has the most negative SRP (most electropositive)

Asker's Comment:
Thank you