AQA C1 Chapter 4: Fuels from oil

Crude oil

A fossil fuel made from the fossilised remains of plants and animals that lived in the sea. Is a mixture of different hydrocarbons that need to be separated. Non-renewable.

Fossil fuel

Any fuel such as coal, oil and natural gas that is made from the fossilised remains of plants and animals that died millions of years ago. Non-renewable.


A compound containing only the elements hydrogen and carbon.


A hydrocarbon that has all carbon-to-carbon single bonds.


A hydrocarbon that has at least one carbon-to-carbon double bond.

Fractional distillation

The process used to separate the different hydrocarbons in crude oil. The oil is heated to a vapour then different fractions condense back to a liquid as they pass up the fractionating column and cool down. Lowest boiling points travel the highest up the


A small part of the separated hydrocarbons from crude oil. Different fractions have different uses and properties.

Complete combustion

Combustion (burning) that happens in a rich supply of oxygen. The products are carbon dioxide and water.

Incomplete combustion

Combustion (burning) that happens when oxygen supply is low. Produces carbon monoxide and water.

Natural gas

Another fossil fuel made of mostly methane gas.


Solid particles left over when fossil fuels burn. Can turn buildings black (soot) or cause asthma.

Carbon monoxide

Toxic gas produced by incomplete combustion that stops red blood cells being able to carry oxygen. Can cause death.

Sulphur dioxide

A gas formed by burning impure fossil fuels that contain sulphur. Dissolves in clouds to form acid rain.


A store of chemical energy that can be burned to release heat.

Greenhouse gas

A gas such as carbon dioxide or methane that increases the greenhouse effect.

Greenhouse effect

The effect that keeps heat trapped on Earth and prevents it being radiated back into space. Leads to global warming.

Acid rain

Rain that has been made acidic by dissolved sulphur dioxide and nitrogen dioxides. Can corrode limestone buildings and harm fish and plants.


A natural process that makes ethanol from sugar.

Hydrogen fuel cell

A device that combines hydrogen with oxygen to produce electricity.


Ethanl that has been produced from natural, renewable resources by fermentation.


A resource that will all be gone once it has been used.