AQA GCSE Chemistry
AQA GCSE Chemistry 4.9.3 Common Atmospheric Pollutants and Their Sources Exam Questions
Free AQA GCSE Chemistry exam questions for 4.9.3 Common Atmospheric Pollutants and Their Sources, with a mark scheme for every pack. Covers pollutants from burning fuels, including carbon monoxide, soot, sulfur dioxide and nitrogen oxides, and their effects.
4.9.3 Common Atmospheric Pollutants and Their Sources exam questions
3 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
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About AQA GCSE Chemistry 4.9.3 Common Atmospheric Pollutants and Their Sources
AQA GCSE Chemistry 4.9.3 looks at the pollutants released when fuels burn and the harm they cause. You learn which products form from complete and incomplete combustion, where sulfur dioxide and oxides of nitrogen come from, and the effects of carbon monoxide, particulates, sulfur dioxide and oxides of nitrogen on people and the environment. It is assessed on Paper 2 and builds on combustion of hydrocarbons in 4.7.1. Typical exam questions ask you to match each pollutant to its source and effect, or to interpret data on emissions from different fuels.
What you need to know
- Combustion products Burning fuels releases carbon dioxide, water vapour, carbon monoxide, sulfur dioxide and oxides of nitrogen into the atmosphere. Solid particles and unburned hydrocarbons may also be released, forming particulates.
- Incomplete combustion When there is insufficient oxygen, incomplete combustion produces carbon monoxide and soot (carbon particles).
- Sulfur dioxide Some fuels, such as coal, contain sulfur. When burned, the sulfur reacts with oxygen to form sulfur dioxide.
- Oxides of nitrogen Formed when nitrogen and oxygen from the air react at the high temperatures inside engines.
- Effects Carbon monoxide is a toxic gas that is colourless and odourless, so it is not easily detected. Sulfur dioxide and oxides of nitrogen cause respiratory problems and cause acid rain. Particulates cause global dimming and health problems for humans because they damage the lungs.
Common mistakes in 4.9.3 Common Atmospheric Pollutants and Their Sources
- Saying oxides of nitrogen come from nitrogen in the fuel. They form from nitrogen in the air reacting at high temperature in engines.
- Saying carbon monoxide causes acid rain or global warming. Carbon monoxide is toxic; acid rain is from sulfur dioxide and oxides of nitrogen.
- Forgetting why carbon monoxide is dangerous: it is colourless and odourless, so people cannot detect it.
- Saying sulfur dioxide comes from sulfur in the air. It comes from sulfur impurities in fuels.
- Writing 'pollution' as an effect. Name a specific effect such as acid rain, respiratory problems or global dimming.
Try three 4.9.3 Common Atmospheric Pollutants and Their Sources exam-style questions
1. Explain how carbon monoxide is formed when fuels burn and why it is dangerous. (3 marks)
Show the mark scheme answer
Incomplete combustion; when there is insufficient oxygen; carbon monoxide is toxic and colourless and odourless so it is difficult to detect.
2. Explain why car engines release oxides of nitrogen even though petrol contains no nitrogen. (2 marks)
Show the mark scheme answer
Nitrogen and oxygen from the air react; at the high temperatures in the engine.
3. Give two effects of particulates in the atmosphere. (2 marks)
Show the mark scheme answer
Global dimming; health problems such as lung damage.
4.9.3 Common Atmospheric Pollutants and Their Sources FAQs
What does AQA GCSE Chemistry 4.9.3 cover?
It covers the pollutants produced by burning fuels, including carbon monoxide, soot, sulfur dioxide, oxides of nitrogen and particulates, where they come from, and their effects.
Which paper is 4.9.3 on?
It is part of section 4.9 Chemistry of the atmosphere, assessed on AQA GCSE Chemistry Paper 2.
What is the best way to revise pollutants?
Make a three-column table: pollutant, how it forms and its effect. Learn exact wording such as 'toxic, colourless and odourless' for carbon monoxide and 'global dimming' for particulates.
