Which term best describes a reaction where a fuel reacts with oxygen?

• A. Endothermic
• B. Combustion
• C. Oxidation
• D. Hydrolysis

Answer: (B)

A reaction where a fuel reacts with oxygen is combustion. Combustion is the specific process of burning a fuel in the presence of oxygen, and it is typically exothermic, releasing energy as heat and often light. For example, methane burning in oxygen—CH4 + 2 O2 → CO2 + 2 H2O—releases a lot of energy. This distinguishes combustion from other ideas: endothermic reactions absorb energy rather than releasing it, oxidation is a broader process of reacting with oxygen (or loss of electrons) that can occur in many ways and isn’t limited to burning, and hydrolysis is a reaction with water that breaks bonds, not about fuel reacting with oxygen. So the best description for a fuel reacting with oxygen is combustion.