Name two fuels that are obtained from petroleum.

Describe one environmental problem that can result from the combustion of these fuels in the internal combustion engine and identify the specific combustion product responsible.

Plastic litter is an environmental problem that results from the use of petroleum as a chemical feedstock. Identify the property of plastics that is responsible for this.

One product that is made from crude oil is the chemical feedstock that can be used to synthesize commercial liquid-crystal displays. Discuss the properties that a substance must have to make it suitable for use as a liquid-crystal display.

Any two for [1]

petrol/gasoline

kerosene/paraffin/aviation fuel

diesel

fuel oil/gas oil

petroleum gas/refinery gas

global warming;

carbon dioxide;

OR

air pollution;

carbon monoxide / particulates / oxides of nitrogen/NO/\({\text{N}}{{\text{O}}_{\text{2}}}\) / \({\text{VO}}{{\text{C}}_{\text{s}}}\);

Accept oxides of sulphur/SO₂.

OR

acid rain;

oxides of nitrogen/NO/\({\text{N}}{{\text{O}}_{\text{2}}}\);

Accept oxides of sulphur/SO₂.

slow decomposition / not biodegradeable;

chemically stable;

liquid crystal phase over a suitable range of temperatures;

rapid switching speed;

In part (a) a significant number of candidates named two fuels obtained from petroleum.

A significant number of candidates described the environmental problem.

The non-biodegradable property of plastics was stated correctly by many candidates.

The properties of a material that made it suitable for use as a liquid crystal display demonstrated poor understanding by many candidates.