Cathodic Protection Tester Practice Exam

What term is used to describe the anode in a corrosion cell?

1. Negative

2. Neutral

3. Positively charged

4. Oxidizing agent

The correct answer is: Positively charged

The correct term used to describe the anode in a corrosion cell is "positively charged." In electrochemical reactions, the anode is the electrode where oxidation occurs, meaning that it loses electrons. As a result of this loss of electrons, the anode becomes positively charged relative to the other electrode in the system, which is the cathode. This distinction is critical in understanding how cathodic protection works. In a corrosion cell, the anode is often a metal that loses electrons to the environment, leading to corrosion. By recognizing that the anode is positively charged, one can appreciate why the cathode, where reduction takes place, functions as the site where electrons are gained. The significance of the anode's positive charge also links to its role in providing protection in cathodic protection systems. Sacrificial anodes, for instance, are intentionally made from a more reactive metal that serves to protect less reactive metals by corroding in its place, thus preserving the integrity of the primary structure. In summary, identifying the anode as positively charged provides essential insight into the mechanisms of corrosion and the principles behind cathodic protection systems.