Specification Point 4.11:
Know that a fuel is a substance that, when burned, releases heat energy

Fuel

Fuel: Substance which when burned, releases heat energy

  • This heat can be transferred into electricity, which we use in our daily lives

Examples:

Fuel examples, Edexcel IGCSE Chemistry

Oil, coal and natural gases, which are common fossil fuels used to provide us with electricity

Specification Point 4.12:
Know the possible products of complete and incomplete combustion of Hydrocarbons with Oxygen and air

Products of Combustion

Complete combustion: Occurs when there is an unlimited supply of air so that elements in the fuel react fully with oxygen.

Complete combustion of hydrocarbons:

During the complete combustion of hydrocarbons, carbon dioxide and water will be produced:

  • Carbon will oxidise to form carbon dioxide
  • Hydrogen will oxidise to water

Equation:

Hydrocarbon   +   Oxygen   →   Carbon dioxide   +   Water

Incomplete combustion: Occurs when there is a limited supply of air so that elements in the fuel do not fully react with Oxygen

Incomplete combustion of Hydrocarbons:

During the incomplete combustion of hydrocarbons, water will still be produced but instead of carbon dioxide, carbon monoxide (soot) will form

Equation:

Hydrocarbon   +   Oxygen   →   Carbon Monoxide   +   Water

Specification Point 4.13:
Understand why Carbon monoxide is poisonous, in terms of its effect on the capacity of blood to transport Oxygen

Carbon Monoxide

Carbon monoxide: A poisonous gas that is colourless and odourless, produced during incomplete combustion:

Hydrocarbon   +   Oxygen   →   Carbon monoxide   +   Water

Effect of Carbon monoxide on blood:

  • When carbon monoxide is produced by incomplete combustion, it is absorbed in the lungs and binds with the haemoglobin in our red blood cells.
  • This reduces the capacity of the blood to carry oxygen.
Carbon monoxide atoms, Edexcel IGCSE Chemistry

Carbon monoxide atoms

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Author: Jamie

Jamie got a First class degree in Chemistry from Oxford University before going on to teach chemistry full time as a professional tutor. He’s put together these handy revision notes to match the Edexcel IGCSE Chemistry specification so you can learn exactly what you need to know for your exams.