Cathodic Protection Tester Practice Exam

What is the addition of electrons to a molecule called?

1. Oxidation

2. Reduction

3. Ionization

4. Electrolysis

The correct answer is: Reduction

The addition of electrons to a molecule is referred to as reduction. In the context of redox (reduction-oxidation) chemistry, reduction is defined as a process where a species gains electrons, resulting in a decrease in its oxidation state. This is crucial in various chemical and electrochemical reactions, particularly in cathodic protection systems, where the aim is to protect metal surfaces from corrosion. In cathodic protection, for example, metallic materials are made to act as the cathode in an electrochemical cell, effectively promoting the reduction reactions that protect the metal from oxidizing (corroding). Understanding reduction helps in implementing strategies to manage and mitigate corrosion in infrastructures, pipelines, and other metallic systems exposed to corrosive environments. While oxidation involves the loss of electrons and an increase in oxidation state, ionization pertains to the process of an atom or molecule gaining or losing electrons to form ions. Electrolysis, on the other hand, refers to the chemical decomposition produced by passing an electric current through a liquid or solution that conducts electricity. Each of these terms describes a different chemical process, highlighting the significance of reduction as the specific reaction that involves electron gain.