Combustion of Alkenes (OCR GCSE Chemistry A (Gateway Science Suite)): Revision Notes
7.2.2 Combustion of Alkenes
All hydrocarbons can combust (burn in oxygen) to release energy.
Alkenes combust, but they are less likely than alkanes to combust completely.
Complete combustion of alkenes produces carbon dioxide and water, provided there is a plentiful supply of oxygen.
Incomplete combustion of alkenes occurs where oxygen is limited and produces water, carbon monoxide and carbon (soot). This causes a smoky flame.
Functional group
Alkenes have a functional group C=C – the part of the molecule that takes part in reactions. Alkanes, in contrast, do not have a functional group and are less reactive as a result.
Complete combustion of alkenes produces carbon dioxide and water, provided there is a plentiful supply of oxygen.
Here are the equations for the complete combustion of propene: