Cathodic Protection Tester Practice Exam

What is the definition of a cathode in electrochemistry?

1. A positively charged electrode

2. A negatively charged electrode

3. An anode typically

4. An oxidized material

The correct answer is: A negatively charged electrode

In electrochemistry, a cathode is defined as a negatively charged electrode where reduction reactions occur. This is the site where electrons are gained by the chemical species in the solution, leading to a decrease in oxidation state, which characterizes the reduction process. When a circuit is formed, electrons flow into the cathode from the external circuit, thus maintaining its negative charge. The properties of the cathode are crucial in various applications, such as in batteries and electrolytic cells, where understanding the flow of electrons and how materials interact at the electrode surfaces is essential for efficiency and functionality. In contrast, a positively charged electrode, known as the anode, is where oxidation occurs, and materials lose electrons. Recognizing the roles these electrodes play in electrochemical reactions is fundamental in the study and application of cathodic protection systems, as one aims to prevent corrosion by ensuring the proper functioning of these electrodes through various methods and materials.