Cambridge IGCSE Chemistry
Cambridge IGCSE Chemistry 10 Chemistry of the Environment Exam Questions
Free Cambridge IGCSE Chemistry revision for 10 Chemistry of the Environment: what you need to know, common mistakes and exam-style questions with answers. Covers tests for water, water treatment, fertilisers, composition of air, air pollutants, greenhouse gases, climate change, acid rain and catalytic converters.
Practise 10 Chemistry of the Environment with past papers
Once you have learnt this topic, find the 10 Chemistry of the Environment questions in real Cambridge IGCSE Chemistry past papers and mark them with the mark scheme. Doing lots of real questions is the quickest way to learn how examiners ask about each idea.
StemUp mark scheme flashcards
GCSE Chemistry Triple Science Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
From £7.99View flashcards
About Cambridge IGCSE Chemistry 10 Chemistry of the Environment
Chemistry of the environment in Cambridge IGCSE Chemistry 0620 covers water, fertilisers, and air quality and climate. You need chemical tests for water and its purity, the substances found in natural water and how domestic water is treated, the role of NPK fertilisers, the composition of clean, dry air, and the sources and effects of common pollutants. Extended candidates also explain the greenhouse effect in terms of absorbing and emitting thermal energy, and write equations for catalytic converters and acid rain chemistry. It links to combustion of fuels in organic chemistry and to the Haber process. Examiners ask short recall questions and longer explanations of climate change and pollution control.
What you need to know
- 10.1 Tests for water Water turns anhydrous copper(II) sulfate from white to blue and anhydrous cobalt(II) chloride from blue to pink. Pure water melts at 0 °C and boils at 100 °C. Distilled water is used in practical work because it has fewer impurities.
- 10.1 Water supply Natural water can contain dissolved oxygen and useful mineral salts, but also harmful substances such as metal compounds, plastics, sewage, microbes, and nitrates and phosphates from fertilisers. Treatment involves sedimentation and filtration, carbon to remove tastes and odours, and chlorination to kill microbes.
- 10.2 Fertilisers Ammonium salts and nitrates are used as fertilisers. NPK fertilisers supply nitrogen, phosphorus and potassium, the elements plants need for growth.
- 10.3 Clean air Clean, dry air is about 78% nitrogen and 21% oxygen; the rest is a mixture of noble gases and carbon dioxide.
- 10.3 Pollutants Carbon dioxide (combustion of fuels) and methane (decomposition, cattle) cause climate change. Carbon monoxide and particulates come from incomplete combustion; oxides of nitrogen form in car engines; sulfur dioxide comes from burning fuels containing sulfur and causes acid rain.
- 10.3 Climate change Greenhouse gases absorb and re-emit thermal energy (infrared radiation), so less escapes into space and global temperatures rise. Strategies include planting trees, reducing livestock farming, using less fossil fuel and more hydrogen or renewable energy.
- 10.3 Reducing pollution (Supplement) Catalytic converters remove harmful gases, e.g. 2CO + 2NO → 2CO2 + N2. Flue gas desulfurisation uses calcium oxide to remove sulfur dioxide. Photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2.
Common mistakes in 10 Chemistry of the Environment
- Saying the greenhouse effect is caused by the hole in the ozone layer. It is caused by greenhouse gases absorbing and re-emitting infrared radiation.
- Saying carbon dioxide causes acid rain. Acid rain is mainly caused by sulfur dioxide and oxides of nitrogen.
- Saying chlorination removes solids from water. Chlorine kills microbes; sedimentation and filtration remove solids.
- Using copper(II) sulfate to test for water without saying anhydrous. Only anhydrous copper(II) sulfate turns from white to blue.
- Saying oxides of nitrogen come from nitrogen in the fuel. They form when nitrogen and oxygen from the air react at the high temperature in engines.
Try three 10 Chemistry of the Environment exam-style questions
1. Describe a chemical test for water and give the result. (2 marks)
Show the mark scheme answer
Add anhydrous copper(II) sulfate (or anhydrous cobalt(II) chloride); turns from white to blue (or blue to pink).
2. Calculate the percentage by mass of nitrogen in ammonium nitrate, NH4NO3. (Ar: N = 14, H = 1, O = 16) (2 marks)
Show the mark scheme answer
Mr = 14 + 4 + 14 + 48 = 80; percentage N = 28 / 80 x 100 = 35.0%.
3. Explain how increasing the concentration of carbon dioxide in the atmosphere leads to climate change. (3 marks)
Show the mark scheme answer
Carbon dioxide is a greenhouse gas; it absorbs and re-emits thermal energy / infrared radiation emitted by the Earth's surface; less thermal energy escapes into space so average global temperatures increase.
10 Chemistry of the Environment FAQs
What does Cambridge IGCSE Chemistry 10 Chemistry of the Environment cover?
It covers tests for water, water treatment, fertilisers, the composition of air, the sources and effects of air pollutants, greenhouse gases and climate change, and ways to reduce pollution.
Which papers is 10 Chemistry of the Environment examined in?
Every topic in the 0620 syllabus can be tested in Paper 1 and Paper 3 (Core) or Paper 2 and Paper 4 (Extended), with Supplement content only in the Extended papers. Practical skills linked to the topic can also appear in Paper 5 (Practical Test) or Paper 6 (Alternative to Practical).
Which pollutants should I learn for Chemistry of the Environment?
Learn the source and effect of carbon dioxide, methane, carbon monoxide, particulates, oxides of nitrogen and sulfur dioxide, plus at least one way to reduce each. Extended candidates should also learn the catalytic converter equation.
