Use this poster and classroom activity to ensure your 14–16 students understand this important industrial application of separation

Crude oil is a mixture of many different compounds. It mainly consists of hydrocarbons – molecules made only of carbon and hydrogen atoms. Hydrocarbons have different uses depending on their properties. Some are useful as fuels and others are used as feedstock – raw materials – for the petrochemical industry where they are used to make products such as polymers, solvents and detergents.

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Infographic poster, fact sheet and differentiated synoptic question worksheets. Put the poster up in your classroom or display it on a projector. Alternatively, print and hand it out.

Use the differentiated synoptic questions to consolidate prior learning on the topics of bonding, structure and the properties of matter and changes of state.

  • Poster as pdf
  • Fact sheet as MS Word or pdf
  • Foundation synoptic question worksheet as MS Word or pdf
  • Higher synoptic question worksheet as MS Word or pdf
  • Teacher guidance, including answers to the synoptic question worksheets, as MS Word or pdf 


The different hydrocarbons in crude oil must be separated in order to be useful. Fractional distillation separates crude oil into fractions – groups of hydrocarbon molecules with similar carbon chain lengths, properties and boiling points. Each fraction has a different use.

Did you know …?

The oil tankers that carry crude oil to refineries are some of the largest ships and can be over 350 metres long. That’s approximately four football pitches!

The process of fractional distillation

Did you know …?

New cars and vans powered wholly by petrol and diesel will not be sold in the UK from 2030. 

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Did you know …?

Fractional distillation is also used to separate nitrogen and oxygen from air. The air is first liquefied by cooling to below -200ºC then the gases are separated based on their boiling points (nitrogen -196ºC and oxygen -183ºC).

All illustrations  © Dan Bright