The document discusses water impurities and methods for purifying water. It notes that while 71% of Earth is covered in water, only a small portion is potable. Water becomes polluted through waste and spillage. Impurities can be soluble, like salt, or insoluble, like sand. Soluble impurities are removed through evaporation or distillation. Insoluble impurities are removed by sedimentation, decantation, or filtration. Finally, drinking water is purified further through boiling or chlorination after removing other impurities.

1. WATER AND ITS IMPURITIES

2. Importance of Water
 Almost 71 % of earth is covered with water in
the form of oceans,rivers,lakes etc.
 But very less amount of water is potable i.e.
fit for human consumption .

3. Water Impurities
 The substances that pollute water are called
‘Water Impurities’.
 Water is being polluted by throwing wastes
into rivers,oil leakage by water transport etc.

4. Types of Impurities

5. Soluble Impurities
 Impurities that can be dissolved in water are
called Soluble Impurities.
 Examples are-Salt,any other chemical.

6. Insoluble Impurities
 Impurities that cannot be dissolved in water
are called Insoluble Impurities.
 Examples-Sand,Mud.

7. Removing Soluble Impurities
from water
 Evaporation
It is the process of turning
Water into vapours.
 Distillation
The process of purifying water
by heating and cooling.

8. Removing insoluble impurities
from water
 Sedimentation
 Decantation
 Filtration

9. Definitions of process of
removing insolube impurities
 Sedimentation-The process of settling or
being deposited as a sediment.
 Decantation-It is the process for the
separation of mixtures,by removing a layer of
liquid,generally one from which a precipitate
has settled.
 Filtration-The process of removing
something unwanted from a liquid by using a
filter.

10. Purifying drinking water
 After removing soluble and insoluble
impurities,drinking water is purified by two
process i.e. ‘Boiling’ and ‘Chlorination’.

11. REFRENCE SLIDE
 N.C.E.R.T Book
 Google Images