Question

What are the advantages of corrosion?

(a) Protection of metals by surficial oxide layer

(b) Zn-carbon electrochemical reactions in the battery

(c) Decrease in the strength of material

(d) Protection of metals by the surficial oxide layer and Zn-carbon electrochemical reactions in the battery

This question was posed to me in an online quiz.

The doubt is from Corrosion and its Classification topic in section Corrosion Principles of Corrosion Engineering

Answer 1

Correct choice is (d) Protection of metals by the surficial oxide layer and Zn-carbon electrochemical reactions in the battery

To elaborate: Initially passivating metals undergoes corrosion in order to form oxide layer. These thick, dense oxide layer acts as a strong barrier and protects the inner metal against corrosion. The Zn-carbon batteries works on the principle of galvanic corrosion. It involves conversion of chemical energy into electrical energy by these electrochemical reactions.