Question
Question (4 marks): Petrol is a hydrocarbon fuel. Explain how the combustion of petrol in a car engine can produce carbon monoxide and oxides of nitrogen, and give one problem caused by each.
Mark scheme (4 marks):
- Carbon monoxide is produced by incomplete combustion (insufficient oxygen) (1)
- Carbon monoxide is toxic — binds to haemoglobin and reduces oxygen transport in the blood (1)
- Oxides of nitrogen form because nitrogen and oxygen in the air react at the high temperatures in the engine (1)
- NOₓ cause acid rain / respiratory problems / photochemical smog (1)
4 marks · take your time before peeking.
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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.