Topoic 14 - Fertilisers

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Topoic 14 - Fertilisers
2011-04-04 09:35:45
Chemistry Fertilisers

Standard Grade Chemistry - Topic 14 - Fertilisers
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  1. Why must we have more efficient food production?
    Due to the rapid increase in world population
  2. What are the lumps on plant roots called and what do they contain?
    They are called nodules and they contain nitrifying bacteria
  3. Plant which fix atmospheric nitrogen are called....?
  4. What can be added to the soil if it is short of essential nutrients?
    A fertiliser
  5. What are the problems with fertilisers?
    They are usually very soluble and can be washed into rivers and lochs. This can encourage the rapid growth of bacteria on the river surface - killing the animal and plant life living there.
  6. What are the main elements needed by plants?
    • Nitrogen - N
    • Potassium - K
    • Phosphorus - P
  7. What is a fertiliser?
    A substance which replaces the essential elements in the soil and encourages plant growth
  8. What colour does ammonia turn pH paper?
  9. What does the Haber process make from nitrogen and hydrogen?
  10. What is the catalyst used in the Haber process?
  11. Where does the nitrogen and hydrogen come from for the Haber process?
    • The nitrogen comes from the air
    • The hydrogen comes from the air or from hydrogen gas
  12. Why is the Haber process carried out at a moderate temperature?
    As at a low temperature it is too slow. At a moderate temperature the reaction gives the best yield for the money you put in
  13. The Haber process is a ________ reaction?
  14. In the Haber process what happens to unreacted nitrogen and hydrogen?
    They are recycled
  15. In the Haber process how is ammonia seperated from the other reactants?
    By oxidising the ammonia
  16. What is the test for ammonia?
    It is very soluble in water forming an alkali solution
  17. In industry ammonia is oxidisec in the _______ process?
  18. In the Ostwald process, ammonia reacts with oxygen from the air to form the gas....?
    nitrogen monoxide
  19. In the Ostwald process the nitrogen monoxide then reacts with oxygen from the air to form brown ________ ________ gas?
    nitrogen dioxide
  20. What is the catalyst used in the Ostwald process?
  21. Why is it not necessary to continue to heat the reaction in the Ostwald process once it has started?
    As the reaction is highly exothermic
  22. What is formed when nitrogen dioxide gas dissolves in water?
    nitric acid
  23. Ammonia reacts with _________ solutions to form ammonium salts?
    nitric acid