Question

According to the electrochemical concept, corrosion occurs at :

• A. anodic area of metal
• B. cathodic area of metal
• C. both cathodic and anodic areas of metal
• D. neither cathodic area nor anodic areas of metal

Answer 1

Answer: (A)

anodic area of metal

Corrosion can be defined as the deterioration of materials by chemical processes.

Of these, the most important by far is electrochemical corrosion of metals in which the oxidation process $M\to M^{+}+e^{-}$ is facilitated by the presence of a suitable electron acceptor. This is possible because metals are conductive and so, the electrons can flow through the metal from the anodic to the cathodic regions.
Metallic corrosion occurs when metal atoms are oxidized and subsequently leave the metal lattice as ions. The oxidation reaction of the metal is referred to as the anodic half-reaction. The areas on a metal surface where oxidation occurs are referred to as anodes.

Option A is correct.