GCSE Chemistry

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GCSE Chemistry
2012-04-09 05:13:12
limestone building materials topic

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  1. what two raw materials are used to make cement
    • limestone
    • clay
  2. what 3 substances is cement mixed with to make concrete
    • sand
    • water
    • aggregate (crushed rock)
  3. what raw material is mixed with limestone and heated in a kiln to produce cement
  4. in the kiln the raw materials are heated to about 1500°C . The limestone (calcium carbonate) is broken down at this temperature . Complete the word equation for this reaction
    calcium carbonate ==> ------- ---- + carbon dioxide
    calcium carbonate ===> calcium oxide + carbon dioxide
  5. suggest one major cost of this process (making cement by nmixing clay and lim estone and heating them in a kiln) other than the cost of the raw materials
    the cost of the fuel needed to power the kiln
  6. name a naturally occuring form of calcium carbonate
  7. what does thermal decomposition mean
    the breaking down of a substance using heat
  8. an old lime kiln made in the ground is shown

    suggest and explain the purpose of the coal
    the coal will react with the oxygen , and the coal will , burn this will help keep the temperature high
  9. write a word equation for the thermal decomposition of calcium carbonate
    calcium carbonate ==> calcium oxide + carbon dioxide
  10. when drops of cold water are added tocalcium oxide cracks appear in the white solid , give the chemical name of the white solid formed , give a use of this solid
    • name : calcium hydroxide
    • use : to neutralise acidic fields , or to make cement or mortar
  11. limestone has many uses . choose from the list two important materials made from limestone
    cement , disel , glass , poly(ethene) , sodium hydrocide , sulphuric acid
    • cement
    • glass
  12. the diagram shows a lime kiln . the limestone is heated by burning coal

    suggest why hot air is blown into the lime kiln
    to allow the coal to burn
  13. give two reactions which produce carbon dioxide in the lime kiln
    • calcium carbonate ==> calcium oxide + carbon dioxide
    • carbon + oxygen ==> carbon dioxide
  14. calcium oxide can be converted into calium hydroxide by adding water . write a word equation to represent this reaction
    calcium oxide + water ==> calcium hydroxide
  15. why do farmers sometimes add calcium hydroxide to acidic soil
    to neutralise the soil