By David Fowkes on Saturday, 13 October 2018
Category: IGCSE Chemistry

4.7 - 4.9 Crude oil

Crude oil is a major source of raw material for the petrochemical industry. 

 4.7 A valuable mixture

Ancient marine animals trapped in sedimentary rocks millions of years ago decomposed to form a mixture of hydrocarbons known as crude oil. Crude oil is found in underground reservoirs, trapped in rock formations. It is pumped up to the surface before being refined. 

 Assumed background knowledge

 4.7 Activity 1. What's in the mix?

 Students should:

  • 4.7 know that crude oil is a mixture of hydrocarbons

 4.8. Activity 2. Dividing the fractions

 Students should:

  • 4.8 describe how the industrial process of fractional distillation separates crude oil into fractions

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 Students should:

  • 4.9 know the names and uses of the main fractions obtained from crude oil: refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen
  • 4.10 know the trend in colour, boiling point and viscosity of the main fractions

 4.11 - 4.12 Activity 4. Open Air

 Students should:

  • 4.11 know that a fuel is a substance that, when burned, releases heat energy
  • 4.12 know the possible products of complete and incomplete combustion of hydrocarbons with oxygen in the air

​Many of the hydrocarbons obtained from crude oil are combustible. They will burn in the oxygen of the air to produce the oxides of hydrogen ( water ) and carbon. The reaction releases energy and is therefore exothermic.