6th Class Science Separation of Substances Separation of Substances

     Separation of Substances

Most of the substances available in the nature are in the mixture form. Mixtures are separated into their constituents as per our requirement. In this chapter we will study about mixtures and some methods of their separation.

Pure Substances: The substances which are made up of only one kind of atoms or molecules are called pure substances. For example gold, silver, copper etc.

Mixture: When two or more than two different substances are mixed up together a mixture is formed. For example air is a mixture of many gasses like nitrogen, oxygen, carbon dioxide and some other gasses.

Constituents of a Mixture: The different substances which are present in a mixture are called constituents of the mixture. For example nitrogen, oxygen, carbon dioxide and many other gasses which are present in the air are constituents of air.

Homogeneous mixture: A mixture that is uniform in composition is called Homogeneous mixture. Example air, milk, salt water solution etc.

Heterogeneous mixture: A mixture that is not uniform in composition is called Heterogeneous mixture. Example mixture of air and water, sandy water, orange juice with pulp in it etc.

Why do we separate mixtures?

We separate mixtures for the following purposes:

(a) For removing undesirable constituents

(b) For obtaining useful constituents

(c) For obtaining the pure substances

Now let us study some method of separation of mixtures..