Humber Admissions Practice Test

Which reaction is characterized by a substance reacting with oxygen and releasing energy as heat and light?

1. Precipitation Reaction

2. Redox Reaction

3. Combustion Reaction

4. Neutralization Reaction

The correct answer is: Combustion Reaction

A reaction characterized by a substance reacting with oxygen while releasing energy as heat and light is best described as a combustion reaction. In this type of reaction, a fuel (often a hydrocarbon) combines with oxygen to produce carbon dioxide, water, and energy. The release of energy in the form of heat and light is what defines combustion, making it a highly exothermic process. Combustion is a common reaction seen in everyday life, such as the burning of wood in a fire or the burning of gasoline in an engine. These examples highlight how combustion is not just an industrial term, but an essential part of many activities. Precipitation reactions, while they do involve a chemical change that produces a solid from solutions, do not necessarily involve the reaction with oxygen or the release of energy as heat and light. Redox reactions encompass a broad category of reactions where there is a transfer of electrons, which may or may not involve combustion, while neutralization reactions specifically refer to the reaction between an acid and a base, often resulting in the formation of water and a salt, without the characteristic release of energy that defines combustion.