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Removing Insoluble Impurities

Insoluble impurities can be separated from
water by three methods : sedimentation ,
decantation and filtration.

Sedimentation
Water with insoluble impurities is kept

undisturbed. After some time, the insoluble
impurities settle down at the bottom of the

vessel. This process is called sedimentation.

Decantation
In sedimentation, the impurities settle down at the bottom and you can get

clean water above. This clean water is slowly poured into another container.
This process is known as decantation.

Knowledge Plus

A dripping tap can waste up to 6 litres of water in a day.

Filtration

Here the impure liquid is passed through a filter
paper. The filter paper works like a strainer which is

used to filter tea leaves from tea at home.
Removing Soluble Impurities

How can we separate soluble substance from water?
Soluble impurities can be separated by evaporation

and distillation.

Evaporation
It is the process of changing water into vapours on

heating. When water evaporates, it leaves all the
dissolved impurities at the bottom.

Distillation

Distillation is the process by which we get pure water, free from all minerals,

salts, and other impurities. This process includes evaporation and
condensation by which we get pure distilled water. Water is first heated and
then it evaporates. The water vapours are cooled and they condense into

water which is collected in another flask.

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