Page 54 - ICSE Chemistry 8

We can separate mixtures such as tea and tea leaves, chalk and water, clay and water, and sawdust and
water by fi ltra on.

mixture
unfolded fi rst fold second cone
fold funnel with
Folding of a fi lter paper glass rod fi lter paper

residue
cone and
residue

clamp stand

fi ltrate
Filter paper
Fig. 3.7: Filtration using a funnel and fi lter paper

Take a Break!

Fill in the blanks.
1. The principle of the technique of ______________ is the diff erence in size of the components of a
mixture.

2. ______________ is the method of separa ng components of a mixture using wind or moving air.
3. The process used to separate components of a mixture based on their rela ve solubility is called
______________.
4. We can separate a mixture of common salt and potassium nitrate by ____________________.

5. The solid par cles that se le down in the process of sedimenta on are called ______________.
6. The insoluble solid par cles that are le behind in the fi lter are called ______________.

Evaporation

The process by which a liquid changes into its vapour state by solution
hea ng is called evapora on. This method is used to separate
sand bath evaporating
homogeneous solid-liquid mixtures. We can separate salt dish
from seawater by evapora on. In this process, seawater is
wire gauge
collected in shallow beds and is le to be evaporated in the
sun. Salt is le behind when all the water is evaporated. The
tripod stand burner
liquid, here water, escapes in the form of vapour and the
solid, here salt, is obtained.
We can also separate copper sulphate crystals from copper
sulphate solu on by evapora on.
Fig. 3.8: Evaporation

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