Page 46 - ICSE Chemistry 6

Some More Methods of Separa on
Handpicking

Handpicking is the most commonly used method of separa on in our daily lives.
When the quan ty of the mixture is small, impuri es like stones and husk can be
easily removed from it by handpicking.

Winnowing Handpicking
Winnowing is an ancient agricultural prac ce which is used to separate lighter
par cles of a mixture from heavier ones.
In winnowing, the mixture is dropped from a height. In this way the lighter
par cles get blown away by the wind and the heavier par cles fall on the
ground near the place of winnowing.
Winnowing

Threshing
This method is used to separate grains from stalks. Stalks are dried in the sun
before the grains are separated from them. The stalks are then beaten to remove
the seed grains.

Solvent Extrac on Threshing
Solvent extrac on is used when one of the solid cons tuent is soluble in a liquid. For example, we can
separate a mixture of salt and sand using solvent extrac on method. Salt gets dissolved in water whereas
sand does not. Sand se les down. The two can thus be separated.
Loading
There are some mixtures which contain very fi ne solid par cles that se le down very slowly. These par cles
are made to se le down faster by adding special chemicals like alum. This process is called loading.

Take a Break!

Name the following.

1. Any two mixtures used in daily lives ______________ ______________
2. A method used to separate components of a mixture that diff er in size ______________

3. A clear liquid observed over the sediment ______________
4. An insoluble solid le behind on the fi lter paper ______________

5. A process by which a liquid is converted into its vapour state ______________

Terms to Know

Element: A fundamental substance that cannot be chemically changed or decomposed into
simpler substances by normal chemical means

Atom: The smallest unit of an element that shows all the proper es of that element

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