Chemistry study notes
Maintaining Air Quality
Connect atmospheric substances to their sources, effects and possible solutions.
O-Level 6092 (2026) / SEC G3 K324 (2027)
Spaced review
Remember this chapter
Save this chapter's 8 recall cards. We'll bring each one back just before you're likely to forget it, a few minutes a day.
Free account needed, so your cards follow you to any device. Notes and quick recall stay free without one.
Choose a lesson
5 topicsWhat is in air, and where do pollutants come from?
Separate the normal mixture from substances causing harm.
Explain harm through a chemical cause
Link the pollutant to the process and then the effect.
Use reactions to reduce harmful emissions
Treat the pollutant before release where possible.
Pure onlyOzone: useful high up, harmful near the ground
Location changes the role of the same substance.
Pure onlyCarbon cycling and greenhouse gases
Track the flows before judging whether they balance.
Scope
Learning outcomes
12. Maintaining Air Quality (6092 / K324). Use the outcome map to find the explanation for a particular syllabus requirement.
See the learning outcome map
12(a) Describe dry-air composition
- 78% nitrogen
- 21% oxygen
- Remainder noble gases, mainly argon, and CO2
12(b) Name atmospheric pollutants
- CO, CH4, NO, NO2, O3, SO2, unburned hydrocarbons
12(c) Identify pollutant sources
- CO from incomplete carbon-fuel combustion
- NOx from lightning and engines
- SO2 from volcanoes and fossil fuels
12(e) Explain pollutant effects
- CO toxicity
- NO2/SO2 acid rain
- Respiration and buildings
12(g) Explain the carbon cycle
- Photosynthesis
- Respiration
- Combustion
- Regulation of atmospheric CO2
12(h) Explain greenhouse-gas effects
- CO2 and CH4 sources
- Global warming
- Extreme weather and melting polar ice
12(d) Explain pollution-control reactions
- Catalytic-converter redox
- CaCO3 treating acid rain effects
- Flue gas desulfurisation
12(f) Explain ozone-layer importance and loss
- UV protection
- CFCs and chlorine-related ozone destruction