Question

The cathodic reaction that occurs during corrosion in oxygenated acidic solution is ______

(a) 2H^++2e^–==>H2

(b) 4H^++O2+4e^–==>2H2O

(c) 2H2O+2e^–==>H2+2OH^–

(d) 2H2O+O2+4e^–==>4OH^–

This question was posed to me in an online quiz.

This is a very interesting question from Corrosion and its Classification in section Corrosion Principles of Corrosion Engineering

Answer 1

Correct choice is (b) 4H^++O2+4e^–==>2H2O

The best I can explain: The common hydrogen reduction reaction in corrosion will proceed based on the pH and the amount of oxygen present in the solution. Then oxygenated acidic solution (pH < 7) will react as

4H^++O2+4e^–==>2H2O.