Using resources

• what is sustainable development?

  development that meets the needs of current generations without compromising the ability of future generations to meet their own needs
• in the UK, potable (safe to drink) water is produced by…

  • choosing an appropriate source of fresh water
  • passing the water through filter beds to remove any solids
  • sterilising to kill microbes
• what are the sterilising agents for potable water?

  include chlorine, ozone or ultraviolet light

  • chlorine is a toxic gas so the amount added to water has to be carefully monitored
  • using ultraviolet light to kill microbes avoids adding chemicals to the water but is more expensive
• how is desalination carried out?

  • distillation or by processes that use membranes such as reverse osmosis
  • processes require large amounts of energy
• what is reverse osmosis?

  • sea water is passes through a membrane that only allows through the water molecules
  • needs high pressure to push the water through the membrane
  • the high pressure requires a lot of energy to produce
• how is house water produced and how is it treated?

  • urban lifestyles and industrial processes produce large amounts of waste water that requires treatment before being released into the environment
  • sewage and agricultural waste water require removal of organic matter and harmful microbes
  • industrial waste water may require removal of organic matter and harmful chemicals
• what are the processes involved in sewage treatment?

  • screening and grit removal
  • sedimentation to produce sewage sludge and effluent
  • anaerobic digestion of sewage sludge
  • aerobic biological treatment of effluent
• what do new methods of mining avoid in terms of disadvantages of traditional mining?

  avoids the disadvantages of traditional mining methods of digging, moving and disposing of large amount of rock
• what is phytomining?


  • uses plants to absorb metal compounds from the soil
  • plants are harvested and then burnt to produce ash that contains the metal compounds
• what is bio leaching?

  uses bacteria to produce leachate solutions that contain metal compounds
• advantages and disadvantages of these methods

  need less energy than traditional methods and can work on low concentration ores but are slow to carry out
• describe the stages of LCAs


  carried out to assess the environmental impact of products in each of these stages

  • extracting and processing raw materials
  • manufacturing and packaging
  • use and operation during its lifetime
  • disposal at the end of its useful life, including transport and distribution at each stage
• how do we reduce the use of resources?

  reduction in use, reuse and recycling of materials by end users reduces the use of limited resources, energy consumption, waste and environmental impacts
• advantages and disadvantages of recycling

  • less acid rain (pollution), metal ore reserves last longer, less landfill, creates employment
  • collection problems, cost of transport, difficult to sort
• what is corrosion and how is it prevented?

  • destruction of chemical reactions with substances in the environment
  • applying a coating that acts as a barrier, such as greasing, painting or electroplating - stop the air or water coming into contact with the metal
• describe the sacrificial process

  • some coatings are reactive and may contain corrosion inhibitors or a more reactive metal
  • if 2 metals are in contact, the more reactive metal will corrode instead of the less reactive one
• describe the compounds and the uses of bronze, brass, gold, aluminium-magnesium, steels

  alloys: bz - copper + tin, used for making statues, decorative objects

  br - copper + zinc, used for producing water taps and door fittings

  G - used as jewellery, alloy with silver, copper and zinc

  AM - low density, used in aerospace manufacturing

  S - iron that contain specific amounts of carbon and other metals. High carbon steel is strong but brittle. Low is softer and more easily shaped. Steel containing chromium and nickel (stainless steels) are hard and resistant to corrosion
• how are the properties of polymers determined?

  • depend on what monomers they are made from and the conditions under which they are made
  • ex. low density and high density poly(ethene) are produced from ethene, using different catalysts and reaction conditions
• describe the structures of thermosoftening and thermosetting polymers?


  • sett - don’t melt on heating, polymer molecules are linked to each other by strong cross-links
  • sof - soften easily on heating and can then be remoulded, keeping the new shape on cooling, polymer molecules are attracted to each other by weak intermolecular forces
• how is glass made?

  • most is soda-lime, made by heating a mixture of sand, sodium carbonate and limestone
  • borosilicate glass, made from sand and boron trioxide, melts at higher temperatures than soda-lime glass
• how are clay ceramics made?

  shaping wet clay and then heating in a furnace
• how are composites formed?

  fibres or fragments of one material (reinforcement) are surrounded by a binder/matrix materials that holds these fibres/fragments together
• Haber process


  1. Purified H2 and N2 gases passed over Fe catalyst

  2. High temperature (450C)

  3. High pressure (200 atm)

  4. Ammonia (N2 + 3H2 >< 2NH3) formed

  5. Reaction is reversible, ammonia breaks down

  6. Ammonia liquefies and removed

  7. Remaining H2 and N2 recycled
• Fe catalyst


  • Speeds up the rate of reaction, so lower temperature could be used
• Ammonia


  Used for production of nitrogen-containing fertilisers
• Haber process uses high T and P conditions. Explain why this is so and why this is a compromise


  compromise between rate and the yield

  • reaction is exothermic, optimum temp is used (450), lower temp would give higher yield, but the rate of NH3 production would be too slow
  • pressure of 200 used, higher pressure would give higher yield, too expensive tho due to cost of energy to produce the high pressure
• how are compounds of nitrogen, phosphorus and potassium used

  • fertilisers to improve agricultural productivity
  • NPK fertilisers contain compounds of all three elements
• how is industrial production of NPK fertilisers achieved?

  • ammonium can be used to manufacture ammonium salts
  • ammonium sulfate , phosphate and nitrate can be produced by reaction of ammonia with the requisite acid

  2 NH3 + H2SO4 > (NH4)2SO42 NH3 + H3PO4 > (NH4)3PO4NH3 + HNO3 > NH4NO3
• how is phosphate rock utilised in the production of fertilisers?

  • reacted with nitric acid to produce phosphoric acid and calcium nitrate
  • can be reacted with sulfuric acid to produce a mixture of calcium phosphate and calcium sulfate
  • can be reacted with phosphoric acid to produce calcium phosphate