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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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water,_hardness_of
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INFOTEXT
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1992-09-01
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12 lines
A term used to describe the inability of some
water to form a lather with soap, and the
production of `fur' or `scale' in kettles. It
is caused by the presence of certain salts of
calcium and magnesium. Temporary hardness is
due to hydrogen carbonates which, on boiling,
are converted to insoluble carbonates to give
scale in kettles. Permanent hardness is due
to sulphates and silicates, which are not
affected by boiling, but can be removed by
using a water softener.