Ever wondered how we turn dirty water into something safe... Show more
Chemistry71 views·Updated Jun 1, 2026·5 pagesGCSE AQA Chemistry Unit 10 Study Notes
Dae 🏎🪩@d_h708
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1
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Using Resources and Water Treatment
You rely on natural resources for everything - your food, clothes, shelter, and energy. The key challenge is using these finite resources sustainably so future generations can meet their needs too.
Potable water (safe drinking water) isn't chemically pure - it contains some dissolved salts but has low levels of harmful substances and microbes. In the UK, we mainly use fresh rainwater from rivers and lakes, which gets filtered and sterilised with chlorine, ozone, or UV light.
When fresh water runs out, desalination turns seawater into drinking water through distillation or reverse osmosis. Reverse osmosis pushes water through special membranes under high pressure, but this requires loads of energy - making it expensive.
Key Point: Potable water contains dissolved substances but is safe to drink, whilst pure water contains no dissolved solids at all.
Sewage treatment removes organic waste and harmful microbes through screening, sedimentation, and biological processes. Industrial wastewater needs extra treatment to remove dangerous chemicals before being released back into the environment.
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Extracting Copper and Life Cycle Assessments
Traditional copper mining is becoming difficult as metal ores become scarce. Two clever new methods are changing the game: phytomining uses plants that absorb copper compounds from soil, whilst bioleaching uses bacteria to extract metals from low-grade ores.
Both methods produce copper compounds that can be turned into pure copper through displacement reactions with scrap iron or electrolysis. These techniques need less energy than traditional mining and work with low-concentration ores, but they're slower and produce smaller amounts.
Life Cycle Assessments (LCAs) evaluate a product's environmental impact from raw material extraction through manufacturing, use, and final disposal. Energy and resource consumption are easy to measure, but judging pollution effects involves subjective decisions.
Key Point: LCAs aren't purely objective - companies can manipulate abbreviated assessments to support advertising claims.
The best approach is reducing, reusing, and recycling materials. Glass bottles can be reused directly or crushed and melted for new products. Metals get recycled by melting and reforming, which conserves ore reserves and reduces energy consumption.
3
of 5
Corrosion Prevention and Alloys
Corrosion destroys materials through chemical reactions with the environment - like when iron rusts in the presence of oxygen and water, forming flaky hydrated iron oxide. Preventing this saves money and keeps structures safe.
You can prevent corrosion by creating barriers through painting, greasing, or electroplating. Sacrificial protection uses more reactive metals like zinc (galvanising) or magnesium blocks that corrode instead of the protected metal. Aluminium naturally forms a protective oxide coating.
Alloys are mixtures of metals designed for specific purposes. Pure metals are too soft because their atoms slide past each other easily. Bronze makes decorative objects, whilst brass creates water taps and door fittings.
Key Point: Steel alloys vary dramatically - high carbon steel is strong but brittle, whilst stainless steel resists corrosion thanks to chromium and nickel.
Different steel types serve different purposes: low carbon steel shapes easily for car bodies, high carbon steel stays hard for tools, and stainless steel resists corrosion for cutlery. Gold jewellery uses alloys measured in carats - 18 carat gold contains 75% pure gold.
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NPK Fertilisers Production
Plants need nitrogen, phosphorus, and potassium to grow properly, which is why NPK fertilisers containing all three elements boost agricultural productivity. These fertilisers are carefully formulated mixtures of various salts with specific percentages of each nutrient.
Ammonia serves as the starting point for making nitrogen-containing fertilisers. It reacts with sulfuric acid to produce ammonium sulfate, or with nitric acid to create ammonium nitrate - both excellent sources of nitrogen for plants.
Phosphate rock gets mined then treated with acids to create soluble phosphorus compounds. Reacting it with nitric acid produces phosphoric acid and calcium nitrate, whilst sulfuric acid treatment creates a mixture of calcium phosphate and calcium sulfate.
Key Point: Phosphate rock cannot be used directly as fertiliser - it must be processed with acids to create water-soluble compounds that plants can actually absorb.
Modern industrial production integrates multiple processes using various raw materials. Potassium chloride and potassium sulfate provide the K component through mining operations, creating complete NPK formulations tailored to specific crop needs.
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of 5
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Chemistry71 views·Updated Jun 1, 2026·5 pagesGCSE AQA Chemistry Unit 10 Study Notes
Dae 🏎🪩@d_h708
Ever wondered how we turn dirty water into something safe to drink, or why your phone contains recycled metals? This topic explores how humans use Earth's resources responsibly, from treating water and extracting metals to preventing rust and making fertilisers... Show more
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Using Resources and Water Treatment
You rely on natural resources for everything - your food, clothes, shelter, and energy. The key challenge is using these finite resources sustainably so future generations can meet their needs too.
Potable water (safe drinking water) isn't chemically pure - it contains some dissolved salts but has low levels of harmful substances and microbes. In the UK, we mainly use fresh rainwater from rivers and lakes, which gets filtered and sterilised with chlorine, ozone, or UV light.
When fresh water runs out, desalination turns seawater into drinking water through distillation or reverse osmosis. Reverse osmosis pushes water through special membranes under high pressure, but this requires loads of energy - making it expensive.
Key Point: Potable water contains dissolved substances but is safe to drink, whilst pure water contains no dissolved solids at all.
Sewage treatment removes organic waste and harmful microbes through screening, sedimentation, and biological processes. Industrial wastewater needs extra treatment to remove dangerous chemicals before being released back into the environment.
2
of 5Sign up to see the content. It's free!
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Extracting Copper and Life Cycle Assessments
Traditional copper mining is becoming difficult as metal ores become scarce. Two clever new methods are changing the game: phytomining uses plants that absorb copper compounds from soil, whilst bioleaching uses bacteria to extract metals from low-grade ores.
Both methods produce copper compounds that can be turned into pure copper through displacement reactions with scrap iron or electrolysis. These techniques need less energy than traditional mining and work with low-concentration ores, but they're slower and produce smaller amounts.
Life Cycle Assessments (LCAs) evaluate a product's environmental impact from raw material extraction through manufacturing, use, and final disposal. Energy and resource consumption are easy to measure, but judging pollution effects involves subjective decisions.
Key Point: LCAs aren't purely objective - companies can manipulate abbreviated assessments to support advertising claims.
The best approach is reducing, reusing, and recycling materials. Glass bottles can be reused directly or crushed and melted for new products. Metals get recycled by melting and reforming, which conserves ore reserves and reduces energy consumption.
3
of 5Sign up to see the content. It's free!
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Corrosion Prevention and Alloys
Corrosion destroys materials through chemical reactions with the environment - like when iron rusts in the presence of oxygen and water, forming flaky hydrated iron oxide. Preventing this saves money and keeps structures safe.
You can prevent corrosion by creating barriers through painting, greasing, or electroplating. Sacrificial protection uses more reactive metals like zinc (galvanising) or magnesium blocks that corrode instead of the protected metal. Aluminium naturally forms a protective oxide coating.
Alloys are mixtures of metals designed for specific purposes. Pure metals are too soft because their atoms slide past each other easily. Bronze makes decorative objects, whilst brass creates water taps and door fittings.
Key Point: Steel alloys vary dramatically - high carbon steel is strong but brittle, whilst stainless steel resists corrosion thanks to chromium and nickel.
Different steel types serve different purposes: low carbon steel shapes easily for car bodies, high carbon steel stays hard for tools, and stainless steel resists corrosion for cutlery. Gold jewellery uses alloys measured in carats - 18 carat gold contains 75% pure gold.
4
of 5Sign up to see the content. It's free!
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NPK Fertilisers Production
Plants need nitrogen, phosphorus, and potassium to grow properly, which is why NPK fertilisers containing all three elements boost agricultural productivity. These fertilisers are carefully formulated mixtures of various salts with specific percentages of each nutrient.
Ammonia serves as the starting point for making nitrogen-containing fertilisers. It reacts with sulfuric acid to produce ammonium sulfate, or with nitric acid to create ammonium nitrate - both excellent sources of nitrogen for plants.
Phosphate rock gets mined then treated with acids to create soluble phosphorus compounds. Reacting it with nitric acid produces phosphoric acid and calcium nitrate, whilst sulfuric acid treatment creates a mixture of calcium phosphate and calcium sulfate.
Key Point: Phosphate rock cannot be used directly as fertiliser - it must be processed with acids to create water-soluble compounds that plants can actually absorb.
Modern industrial production integrates multiple processes using various raw materials. Potassium chloride and potassium sulfate provide the K component through mining operations, creating complete NPK formulations tailored to specific crop needs.
5
of 5Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content: Chemistry in Society
2Most popular content in Chemistry
9Most popular content
9Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user