What chemical change accompanies the process of combustion?

• A. Reduction
• B. Condensation
• C. Oxidation
• D. Decomposition

Answer: (C)

During combustion, a chemical reaction occurs where a substance (typically a fuel) reacts with oxygen to produce heat and light. This process fundamentally involves the oxidation of the fuel, as it loses electrons when reacting with oxygen. Oxidation is characterized by an increase in oxidation state, which is a hallmark of combustion reactions.

In the case of burning hydrocarbons, oxygen combines with carbon in the fuel to form carbon dioxide and with hydrogen to form water. The overall transformation results in products that are usually at a lower energy state than the original reactants, and this energy difference is what is released as heat and light during combustion.

Understanding the importance of oxidation in combustion helps to clarify why this option is the correct choice. Other processes like reduction (which involves a gain of electrons), condensation (phase change from gas to liquid), and decomposition (breaking down of a compound into simpler substances) do not adequately describe the primary chemical change occurring in combustion.