Page 62 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Complete the table given below:

Occasion / Method of Property used for
separation of separation separation

Tea dreg from tea Filtration Difference in the size of
particles

Common salt from sea water
Chaff from paddy

Iron powder from a mixture of
iron powder and aluminium
powder

Table 4.5

The choice of the method of separation of components depends on
the properties of the components of a mixture.

You know that common salt is separated from sea water by
evaporation. Is this method sufficient if water is also to be
obtained through separation? Here distillation
can be used.
Distillation
Condensor
Figure 4.7 depicts the method of distillation. Water out
Water in
Common salt solution is taken in the round
bottomed flask. On heating the solution,

Which component evaporates?
Salt Solution
Which substance will remain in the flask?
What is the reason?
Pure
What happens to the water vapour when Water
it passes through the condenser?
Fig. 4.7 Distillation
When one component of the mixture is volatile and the others
do not vapourise under the same condition, they can be
separated by distillation.

If the components of a mixture possess a large difference in their
boiling points, they can be separated by distillation.

Basic Science VIII 61 61
Basic Science VIII