This deep dive covers Air Pollutants from Burning Fuels within Combustion for GCSE Chemistry. Revise Combustion in Organic Chemistry for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 10 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 13
Practice
20 questions
Recall
15 flashcards
🌫️ Air Pollutants from Burning Fuels
Burning fossil fuels produces more than just CO₂ and water. Three additional pollutants are regularly examined at GCSE: sulfur dioxide, nitrogen oxides, and particulates.
| Pollutant | How it forms | Environmental and health effects |
|---|---|---|
| Sulfur dioxide (SO₂) | Formed when fuels containing sulfur impurities are burned: S + O₂ → SO₂ | SO₂ dissolves in rain → sulfuric acid → acid rain. Damages limestone buildings, kills freshwater fish, strips leaves from trees |
| Nitrogen oxides (NOₓ) | N₂ and O₂ in the air react at the high temperatures inside engines: N₂ + O₂ → 2NO | Cause acid rain and photochemical smog; trigger asthma and lung damage in humans |
| Particulates (soot) | Tiny carbon particles from incomplete combustion of fuels | Cause respiratory problems, blacken buildings, and contribute to global dimming by reflecting sunlight |
Key distinction to remember: SO₂ comes from sulfur in the fuel. NOₓ comes from nitrogen in the air — the high engine temperature causes this normally unreactive gas to react.