Where does corrosion occur in an electrolytic cell?

Corrosion occurs at the anode in an electrolytic cell due to the oxidation process that takes place there. In electrochemical terms, the anode is where metal loses electrons, leading to metal ions dissolving into the electrolyte solution. This loss of metal material is what constitutes corrosion. The anode reaction can typically be represented as a metal giving up electrons and forming cations, which can enter the surrounding solution, leading to the deterioration of the metal.

In contrast, the cathode is where reduction occurs, meaning electrons are gained rather than lost. Therefore, corrosion is not associated with the cathode but rather with the anodic area of the cell. The surface of the water and protective coatings are not primary sites for corrosion; instead, they serve to protect the substrate from environmental factors that contribute to corrosion processes. Thus, the anode is specifically where corrosion is actively occurring in an electrolytic cell context.