C6.1

    Cards (86)

    • Reactivity series
      Metals can be arranged in order of their reactivity from their reactions with water and dilute acids
    • Metals in order of reactivity
      • Potassium
      • Sodium
      • Lithium
      • Calcium
      • Magnesium
      • Zinc
      • Iron
      • Copper
    • Non-metals hydrogen and carbon are often included in the reactivity series
    • Displacement reaction
      A more reactive metal can displace a less reactive metal from a compound
    • Gold is the second to last element in the reactivity series as it is very unreactive, so it is found in the Earth as the metal itself
    • Most metals are found as compounds that require chemical reactions to extract the metal
    • Extracting metals less reactive than carbon
      Reduction of their oxides with carbon
    • Reduction
      Involves the loss of oxygen
    • Electrolysis
      Used to extract metals more reactive than carbon, like aluminium, from their molten compounds
    • Large amounts of energy are used in the extraction process to melt the compounds and produce the electrical current
    • Phytoextraction
      • Some plants absorb metal compounds through their roots and concentrate them
      • The plants can be burned to produce an ash that contains the metal compounds
    • Bacterial extraction

      • Some bacteria absorb metal compounds and produce solutions called leachates which contain the metals
    • Position of equilibrium
      The amount of product formed at equilibrium
    • Rate of reaction
      The speed at which a reaction occurs
    • Lower temperature/pressure
      Gives a favourable position of equilibrium but a slow rate of reaction
    • Higher temperature/pressure

      Can also favour the position of equilibrium but must be limited to save money and avoid danger
    • Almost all industrial processes will use a catalyst
    • Haber process
      Used to manufacture ammonia, which is used to produce nitrogen-based fertilisers
    • Haber process
      1. Nitrogen from air and hydrogen from natural gas/hydrocarbons or steam are passed over an iron catalyst at high temperature and pressure
      2. Some of the hydrogen and nitrogen reacts to form ammonia
      3. The ammonia is liquefied and removed, with the remaining nitrogen and hydrogen recycled
    • Compounds of nitrogen, phosphorus and potassium are used as fertilisers to improve agricultural productivity
    • For plants to absorb these elements, they must be supplied in soluble compounds
    • Industrial production of NPK fertilisers
      1. Ammonia used to manufacture ammonium salts and nitric acid
      2. Potassium chloride, potassium sulfate and phosphate rock obtained by mining
      3. Phosphate rock treated with nitric or sulfuric acid to produce soluble salts
    • Life-cycle assessment
      Carried out to assess the environmental impact of products in each stage: extracting and processing raw materials, manufacturing and packaging, use and operation, disposal
    • Onium salts
      Such as ammonium nitrate and ammonium sulfate
    • Producing ammonium nitrate
      Ammonia + nitric acid → ammonium nitrate
    • Producing ammonium sulfate
      Ammonia + sulfuric acid → ammonium sulfate
    • Minerals obtained by mining
      • Potassium chloride
      • Potassium sulfate
      • Phosphate rock
    • Phosphate rock cannot be used directly as a fertiliser
    • Treating phosphate rock
      Phosphate rock is treated with nitric acid or sulfuric acid to produce soluble salts that can be used as fertilisers
    • Life-cycle assessment
      Assessing the environmental impact of products in each stage: extracting and processing raw materials, manufacturing and packaging, use and operation, disposal at the end of its useful life
    • Use of water, resources, energy sources and production of some wastes can be fairly easily quantified in a life-cycle assessment
    • Allocating numerical values to pollutant effects is less straightforward and requires value judgements, so life-cycle assessment is not a purely objective process
    • Reduction in use, reuse and recycling of materials by end users reduces the use of limited resources, use of energy sources, waste and environmental impacts
    • Materials produced from limited raw materials
      • Metals
      • Glass
      • Building materials
      • Clay ceramics
      • Most plastics
    • Much of the energy for the processes comes from limited resources
    • Obtaining raw materials from the Earth by quarrying and mining causes environmental impacts
    • Products that can be reused
      • Glass bottles
    • Recycling glass bottles
      Glass bottles can be crushed and melted to make different glass products
    • Recycling metals
      Metals can be recycled by melting and recasting or reforming into different products
    • The amount of separation required for recycling depends on the material and the properties required of the final product
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