What are the products of an incomplete combustion reaction?

• A. Carbon Dioxide and Water
• B. Carbon Monoxide and Water
• C. Nitrogen Dioxide and Water
• D. Oxygen and Carbon Dioxide

Answer: (B)

Incomplete combustion happens when there isn’t enough oxygen for the fuel to burn completely. When oxygen is limited, carbon isn’t fully oxidized to carbon dioxide, so the main products are carbon monoxide and water formed from the hydrogen in the fuel. This is why carbon monoxide and water is the best answer.

If there were plenty of oxygen, the burning fuel would produce carbon dioxide and water instead. Nitrogen dioxide and water aren’t typical primary products of standard hydrocarbon combustion, and oxygen gas isn’t produced during combustion—it’s consumed as the reactant. In real fires, you can also get soot or carbon remaining with incomplete combustion, but the primary identifiable products under limited oxygen are carbon monoxide and water.