Hard Water

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  • Created by: Sneha
  • Created on: 10-03-13 20:41
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  • Hardwater
    • soft water: water that forms a rich thick lather
    • hard water: more difficult to form a lather with soap and water.
    • soapless detergents do not produce scum in hardwater.
    • Rain falls through the air and dissolves carbon dioxide, making it slightly acidic.
      • This falls into streams and rivers. These then run along rocks (limestone). The calcium carbonate reacts with the weakly acidic solution. This then becomes calcium hydrogencarbonate.
        • Calcium hydrogencarbonate  is soluble in water.
    • expensive - much more soap required.
    • Heating temporary hard water produces an insoluble solid called scale.
      • This can "fur" up our radiators and kettles and make them less efficient.  - poor conductor of energy.
        • Longer to boil  water, more energy used up and  this costs more money.
  • Hard water contains dissolved compounds that react with soap to form scum
    • Hardwater
      • soft water: water that forms a rich thick lather
      • hard water: more difficult to form a lather with soap and water.
      • soapless detergents do not produce scum in hardwater.
      • Rain falls through the air and dissolves carbon dioxide, making it slightly acidic.
        • This falls into streams and rivers. These then run along rocks (limestone). The calcium carbonate reacts with the weakly acidic solution. This then becomes calcium hydrogencarbonate.
          • Calcium hydrogencarbonate  is soluble in water.
      • expensive - much more soap required.
      • Heating temporary hard water produces an insoluble solid called scale.
        • This can "fur" up our radiators and kettles and make them less efficient.  - poor conductor of energy.
          • Longer to boil  water, more energy used up and  this costs more money.
    • Scum is an insoluble salt.
  • contains dissolved calcium and magnesium ions.
    • Dissolve when streams and rivers flow on rocks that have calcium or magnesium ions.
      • contains dissolved calcium and magnesium ions.

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