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Water - Solubility - Ions

Advantages and Disadvantages of Hard Water.

The advantages of hard water are

1) Most people agree that it tastes better.

2) It is thought to reduce the number of heart illnesses.

3) It provides useful calcium ions for the healthy growth
of bones and teeth.

4) The formation of lime scale in pipes (see below) causes
the inside of the pipe to be covered with insoluble carbonates.
This layer of carbonate prevents the water in the pipe
from coming into contact with the metal of the pipe
and so prevents pipe corrosion and prevents
poisonous metal salts becoming dissolved in the water.

The disadvantages  of hard water are

1) Lime scale furring of kettles and pipes.
The fur is the insoluble carbonate formed
during heating water with temporary hardness.
The deposits of lime scale can build up on the inside of the pipe
restricting the flow of water or causing a blockage.
This can happen in industry where hot water is used
or in domestic heating systems (like the hot water in your house).
Lime scale deposits can be removed using a weak acid.

Lime scale in pipes can be prevented using a water softener
or a scale inhibitor.
Lime scale in pipes can also be an advantage (see above).

2) Soap is wasted because more soap is required for washing.
Soap in hard water forms a "scum" from reacting with
the calcium or magnesium compounds in the water.
Other detergents which do not contain
soap do not form wasteful scum during washing.

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