Atmospheric Pollutants from Fuels
Build confidence in Atmospheric Pollutants from Fuels for GCSE Chemistry with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Burning fuels releases carbon monoxide, soot, sulfur dioxide and nitrogen oxides — know the problem each pollutant causes.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Burning fuels releases several atmospheric pollutants, and each has specific effects.
Carbon dioxide contributes to global warming. Carbon monoxide, from incomplete combustion, is a toxic gas that is colourless and odourless, so it cannot be detected by sight or smell. Particulates cause global dimming and can cause respiratory problems.
Sulfur dioxide comes from sulfur impurities in the fuel and causes acid rain, which damages buildings and statues and harms plants and aquatic life. Oxides of nitrogen form when nitrogen and oxygen in the air react at the high temperatures inside engines, and they also cause acid rain and respiratory problems.
Revision notes
Carbon-based pollutants
Carbon dioxide from complete combustion contributes to global warming.
Carbon monoxide from incomplete combustion is toxic, and is colourless and odourless so it cannot be detected. Particulates of solid carbon cause global dimming and respiratory problems.
Sulfur dioxide
Fuels may contain sulfur impurities, which are oxidised when the fuel burns.
Sulfur dioxide causes acid rain, which damages buildings and statues, and harms plants and aquatic life in lakes and rivers.
Oxides of nitrogen
At the high temperatures inside engines, nitrogen and oxygen from the air react together.
The resulting oxides of nitrogen cause acid rain and respiratory problems. Note the source: they come from the air, not from the fuel.
Key points
- Carbon dioxide contributes to global warming.
- Carbon monoxide is toxic, colourless and odourless.
- Particulates cause global dimming.
- Sulfur dioxide comes from sulfur impurities in fuel.
- Sulfur dioxide causes acid rain.
- Oxides of nitrogen form from air in hot engines.
Worked examples
Example 1
Name two pollutants that cause acid rain. [2 marks]
Model answer
Sulfur dioxide (1 mark) and oxides of nitrogen (1 mark).
Example 2
Explain how oxides of nitrogen are formed when a fuel is burned in an engine. [2 marks]
Model answer
At the high temperatures inside the engine, nitrogen and oxygen from the air react together (1 mark), forming oxides of nitrogen (1 mark).
Example 3
Describe two problems caused by particulates. [2 marks]
Model answer
They cause global dimming, reducing the amount of sunlight reaching the Earth's surface (1 mark). They can also cause respiratory problems in people who breathe them in (1 mark).
Common mistakes
Saying oxides of nitrogen come from the fuel.
They form from nitrogen and oxygen in the air at high temperature.
Saying particulates cause global warming.
They cause global dimming, which is a different effect.
Forgetting that carbon monoxide is undetectable.
Being colourless and odourless is what makes it so dangerous.
Saying acid rain is caused by carbon dioxide.
Sulfur dioxide and oxides of nitrogen cause acid rain.
Exam tips
- Learn each pollutant with its source and its effect.
- Distinguish pollutants from the fuel from those from the air.
- Keep global dimming and global warming separate.
- Give both effects of particulates when asked.
Key terms
- Particulate
- A small solid particle of carbon from incomplete combustion.
- Global dimming
- Reduced sunlight reaching Earth due to particulates.
- Acid rain
- Rain made acidic by sulfur dioxide and nitrogen oxides.
- Oxides of nitrogen
- Pollutants formed from air at high engine temperatures.
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Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.