Cathodic Protection Tester Practice Exam

What happens to ions in an electrochemical cell at the cathode?

1. Ions are oxidized

2. Ions gain electrons

3. Ions are produced

4. Ions are neutralized

The correct answer is: Ions gain electrons

In an electrochemical cell, the cathode is designated as the electrode where reduction occurs. This is a fundamental concept in electrochemistry. At the cathode, ions in the solution gain electrons from the external circuit. This process is known as reduction, which means the oxidation state of the ions decreases as they accept electrons. For example, in a common electrochemical reaction, metal ions in solution may gain electrons to form solid metal. This transformation is crucial because it demonstrates how cathodic reactions play a key role in the overall functioning of batteries and electrochemical cells, allowing energy to be stored and transformed. The other options do not align with the fundamental principles of electrochemistry governing cathodic reactions. Ions are not oxidized at the cathode, since oxidation is a loss of electrons that occurs at the anode. Similarly, while ions can be produced in some reactions, this typically happens in the context of an oxidation reaction, not directly at the cathode where reduction is the focus. Neutralization implies a reaction between acids and bases, which does not pertain directly to the processes occurring at the cathode in an electrochemical context. Hence, the most accurate characterization of the ions' behavior at the cathode is that they gain