PSI Barbering Practice Exam

What type of reaction releases energy in the form of heat?

1. Endothermic reaction

2. Exothermic reaction

3. Redox reaction

4. Combustion reaction

The correct answer is: Exothermic reaction

An exothermic reaction is characterized by the release of energy in the form of heat. During this type of chemical reaction, the products of the reaction contain less energy than the reactants, leading to the release of surplus energy, which often manifests as heat. This is a fundamental concept in chemistry, particularly in thermochemistry, where exothermic reactions are contrasted with endothermic reactions, which absorb heat instead. While combustion reactions are a specific subset of exothermic reactions, not all exothermic reactions are combustion reactions. Therefore, exothermic is the broader term that encompasses any reaction releasing heat. Redox reactions refer to oxidation-reduction processes but do not inherently indicate whether energy is released or absorbed. In summary, an exothermic reaction correctly describes any reaction that results in the release of heat, encapsulating a wide variety of chemical processes.