9.3.2Chemistry of the Atmosphere
Properties and effects of atmospheric pollutants — AQA GCSE Combined Science Trilogy 8464 - Chemistry Revision Notes & Topical Questions
5 min read 6 parts Lesson 11 of 11
Section 1 of 6Carbon monoxide
1Inhaled
- Inhaled The gas is colourless and odourless, so people cannot tell it is present.
2Binds to haemoglobin
- Binds to haemoglobin It attaches to haemoglobin in red blood cells instead of oxygen.
3Less oxygen carried
- Less oxygen carried The blood delivers far less oxygen to the brain and other tissues.
4Harm
- Harm Headaches, fainting, coma and death. Fitting carbon monoxide alarms gives a warning.
Section 2 of 6Particulates and soot
What they are
- What they are Solid carbon particles from incomplete combustion that clump together as soot and slowly settle on surfaces.
Health effects
- Health effects Breathing them in can damage the lungs and cause respiratory problems.
Buildings
- Buildings Soot blackens buildings and statues and can speed up corrosion.
Global dimming
- Global dimming Particles in the air reflect some sunlight back to space, so less light reaches the ground.
Section 3 of 6Making acid rain
1
Sulfur dioxide from burning sulfur-containing fuel, and oxides of nitrogen from hot engines, are released into the air.
2
The gases dissolve in water droplets in clouds.
3
Because they are non-metal oxides, they form acidic solutions, e.g. sulfurous and sulfuric acids from sulfur dioxide and nitric acid from nitrogen oxides.
4
The acidic water falls as acid rain, which corrodes metal and carbonate-rock buildings, harms aquatic life and damages crops and water supplies.
Section 4 of 6Pollutant or greenhouse gas?
Two different problems
Greenhouse gases
- Greenhouse gases Carbon dioxide and methane absorb infrared radiation and contribute to global warming across the whole atmosphere.
Pollutants
- Pollutants These are harmful gases or particles not found in clean air.
- They cause local problems near the ground such as smog and breathing difficulties.
Section 5 of 6Key terms
| Term | Meaning |
|---|---|
| Haemoglobin | The protein in red blood cells that carries oxygen around the body. |
| Acid rain | Rainwater made acidic by dissolved sulfur dioxide and oxides of nitrogen. |
| Global dimming | A reduction in the sunlight reaching the Earth's surface caused by particles reflecting light. |
| Photochemical smog | A harmful haze formed when sunlight reacts with vehicle pollutants including oxides of nitrogen. |
| Non-metal oxide | An oxide of a non-metal that usually dissolves in water to give an acidic solution. |
Section 6 of 6Exam technique
1
Saying carbon monoxide 'stops you breathing'. It prevents haemoglobin carrying oxygen.
2
Treating greenhouse gases and pollutants as the same thing. Acid rain is not caused by the greenhouse effect.
3
Writing that sulfur dioxide itself falls as rain. It dissolves in cloud water to make acidic solutions.
4
Forgetting to link a pollutant to both its source and its effect when the question asks for both.
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