This definitions covers Key Definitions within Combustion for GCSE Chemistry. Revise Combustion in Organic Chemistry for GCSE Chemistry with 25 exam-style questions and 15 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 7 of 13 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
📖 Key Definitions
Complete combustion: The reaction of a fuel with excess (plentiful) oxygen, producing only carbon dioxide and water as products, with maximum energy release. Produces a blue, clean flame.
Incomplete combustion: The reaction of a fuel with limited oxygen, producing carbon monoxide (CO) and/or solid carbon (soot) in addition to water. Produces a yellow/orange smoky flame and less energy than complete combustion.
Carbon monoxide (CO): A toxic, colourless, odourless gas produced during incomplete combustion. It binds to haemoglobin in red blood cells more strongly than oxygen, preventing oxygen transport and causing death.
Practice questions for Combustion
What are the only products formed during the complete combustion of a hydrocarbon?
Explain why carbon monoxide (CO) is toxic to humans. [3 marks]