Question

why is separation of mixtures required

Answer 1

The need for the separation of substances is -
To separate the two useful components
To separate impurities from the useful components
To separate the non-useful substances from the useful ones.

Answer 2

The art of separating mixtures is important because it enables us to isolate pure substances. Mixtures are either homogeneous or heterogeneous. ... Both types of mixtures can beseparated into their component parts by physical means.