(b) Crude oil

Know that crude oil is a mixture of hydrocarbons

Describe how the industrial process of fractional distillation separates crude oil into fractions

Know the names and uses of the main fractions obtained from crude oil: refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen

Know the trend in colour, boiling point and viscosity of the main fractions

Know that a fuel is a substance that, when burned, releases heat energy

Know the possible products of complete and incomplete combustion of hydrocarbons with oxygen in the air

Understand why carbon monoxide is poisonous, in terms of its effect on the capacity of blood to transport oxygen references to haemoglobin are not required

Know that, in car engines, the temperature reached is high enough to allow nitrogen and oxygen from air to react, forming oxides of nitrogen

Explain how the combustion of some impurities in hydrocarbon fuels results in the formation of sulfur dioxide

Understand how sulfur dioxide and oxides of nitrogen contribute to acid rain

Describe how long-chain alkanes are converted to alkenes and shorter-chain alkanes by catalytic cracking (using silica or alumina as the catalyst and a temperature in the range of 600-700 ºC)

Explain why cracking is necessary, in terms of the balance between supply and demand for different fractions