Question

Which of the following is a cathode and anode respectively in the Ag-Fe system?

(a) Iron (Fe) and Silver (Ag)

(b) Silver (Ag) and Iron (Fe)

(c) Gold (Ag) and Iron (Fe)

(d) Iron (Fe) and Gold (Ag)

This question was addressed to me during a job interview.

I would like to ask this question from Modern Theory Principles topic in division Modern Theory Principles of Corrosion Engineering

Answer 1

Right answer is (b) Silver (Ag) and Iron (Fe)

Easy explanation: In the Ag-Fe system, Silver (Ag) (+0.80V) acts as a cathode as the standard hydrogen potential is relatively higher than the Iron (Fe) (-0.44V) and Iron acts as anode due to relatively less standard hydrogen potential.