Using resources

• What do humans use the Earth's resources for?


  Warmth, shelter, food, and transport
• How do natural resources contribute to human needs?


  They provide food, timber, clothing, and fuels
• What are finite resources processed from?


  The Earth, oceans, and atmosphere
• What role does chemistry play in sustainable development?


  It improves agricultural and industrial processes to provide new products sustainably
• What is sustainable development?


  Development that meets current needs without compromising future generations' needs
• What should students be able to do regarding natural products?


  • State examples of natural products supplemented or replaced by agricultural and synthetic products
  • Distinguish between finite and renewable resources
• What skills should students develop regarding resource information?

  • Extract and interpret information from charts, graphs, and tables
  • Use orders of magnitude to evaluate data significance
  • Translate information between graphical and numeric form
• What is potable water?


  Water that is safe to drink
• Why is potable water not pure water in the chemical sense?


  Because it contains dissolved substances
• What are the main methods used to produce potable water in the UK?


  Choosing a source, filtering, and sterilising
• What agents are used for sterilising potable water?


  Chlorine, ozone, or ultraviolet light
• What is required if fresh water supplies are limited?

  Desalination of salty water
• What are the two methods of desalination mentioned?

  Distillation and reverse osmosis
• What should students be able to do regarding potable water?


  • Distinguish between potable water and pure water
  • Describe differences in treatment of ground water and salty water
  • Give reasons for steps used to produce potable water
• Why is waste water treatment necessary?


  To remove organic matter and harmful microbes before release into the environment
• What are the steps involved in sewage treatment?


  Screening, sedimentation, anaerobic digestion, and aerobic biological treatment
• What is the significance of alternative methods of extracting metals?


  They help avoid traditional mining methods and reduce environmental impact
• What are the two alternative methods for extracting copper from low-grade ores?

  Phytomining and bioleaching
• How does phytomining work?


  Plants absorb metal compounds, which are then harvested and burned to produce ash
• What is bioleaching?


  Bacteria produce leachate solutions containing metal compounds
• How can copper be obtained from solutions of copper compounds?


  By displacement using scrap iron or by electrolysis
• What are the stages of a life cycle assessment (LCA)?


  1. Extracting and processing raw materials
  2. Manufacturing and packaging
  3. Use and operation
  4. Disposal at the end of its life
• Why is LCA not a purely objective process?


  Because allocating numerical values to pollutant effects requires value judgements
• What should students be able to do regarding LCAs for shopping bags?


  • Carry out simple comparative LCAs for plastic and paper bags
  • Interpret LCAs of materials or products given appropriate information
• What are ways to reduce the use of resources?

  • Reduce, reuse, and recycle materials
  • Evaluate ways of reducing resource use given appropriate information
• What is corrosion?


  The destruction of materials by chemical reactions with substances in the environment
• What is required for iron to rust?


  Both air and water
• How can corrosion be prevented?


  By applying a coating that acts as a barrier
• What is an example of sacrificial protection?


  Using zinc to galvanise iron
• What are some common alloys?


  • Bronze: copper and tin
  • Brass: copper and zinc
  • Gold alloys: gold with silver, copper, and zinc
  • Steels: iron with carbon and other metals
• What is the significance of the carat measurement in gold alloys?


  It measures the proportion of gold in the alloy
• How do high carbon and low carbon steels differ?


  High carbon steel is strong but brittle, while low carbon steel is softer and more easily shaped
• What is soda-lime glass made from?


  A mixture of sand, sodium carbonate, and limestone
• What is the difference between thermosoftening and thermosetting polymers?


  Thermosoftening polymers melt when heated, while thermosetting polymers do not
• What are the key components of the Haber process?


  • Raw materials: nitrogen and hydrogen
  • Catalyst: iron
  • Conditions: high temperature (about 450°C) and high pressure (about 200 atmospheres)
• What happens to ammonia produced in the Haber process?


  It liquefies on cooling and the remaining gases are recycled
• What are NPK fertilisers composed of?


  • Compounds of nitrogen, phosphorus, and potassium
  • Formulations of various salts with appropriate percentages of elements
• How is phosphate rock treated to produce soluble salts for fertilisers?


  It is treated with nitric acid or sulfuric acid
• What salts are produced when phosphate rock is treated with nitric acid?


  Ammonium nitrate
• What salts are produced when phosphate rock is treated with sulfuric acid?


  Calcium sulfate