Cathodic Protection Tester Practice Exam

In a corrosion cell, what is the role of the cathode?

1. It releases electrons

2. It gains electrons

3. It oxidizes metal

4. It serves as an anode

The correct answer is: It gains electrons

In a corrosion cell, the cathode plays a crucial role in the electrochemical process. It is the electrode where the reduction reaction occurs, meaning it gains electrons. When metal corrodes, oxidation occurs at the anode, where the metal loses electrons, and these electrons then flow through an external circuit to the cathode. At the cathode, the gain of electrons can lead to the reduction of metal ions or other species present in the solution, facilitating the protective processes associated with cathodic protection. The cathode's function is essential in slowing down or preventing the corrosion of the metal, as it effectively mitigates the total electrochemical activity by attracting incoming electrons, which helps in maintaining the integrity of the metal in the corrosion environment. This understanding is fundamental for anyone studying cathodic protection and its application in mitigating corrosion in various systems.