Mixtures are made by mixing 2 or more substances without Chemical Combination.

Most of the materials around us are mixtures, and sometimes we require the different constituents of mixtures. So, we need to separate it by Physical Methods . Let's look at those methods.

 

Methods of separating different components of mixture depends upon the type of mixture.

We consider 3 cases of Separating Mixtures

  • Solid from Solid
  • Solid and Liquid
  • Two Liquids

 

Solid from solid

Solid and solid mixtures can be separated by

  • Using a suitable solvent
    Like we can separate salt and sand by using water water as a solvent (We dissolve both salt and sand in water, salt dissolves, sand doesn't)

  • Using Sublimation
    We heat solid to make it into vapours, and then cool vapours to make solid

  • Using a magnet
    We can separate iron filings from Sand using a Magnet

  • By using Sieves or Hand-Picking

    We can separate stone from pulses using this method

 

Solid and liquid

Solid and liquid mixtures can be separated by

  • Using filtration
    Filtration is used to separate solid substances which are not dissolved in liquid. Like - Sand from Water. It cannot be used to separate Sugar from Water

  • Using Centrifugation
    Centrifugation is used to remove suspended particles from a mixture. Example - Cream from Milk , Blood cells and plasma from Blood

  • By Evaporation
    It used to separate solid substances which are dissolved in liquid. We heat solution until the solvent gets evaporated. Example -  Dye from Ink

  • By Crystallisation
    We cool a hot concentrated solution to obtain crystals. This is similar to Evaporation, but has advantages (check link above). Example - Salt from Sea Water  

  • By Chromatography
    It is used to separate 2 or more dissolved solids in a solution, but these dissolved solids are in very less quantities. Example - Different Dyes from Blank Ink

 

Liquid and liquid

Liquid and liquid mixtures can be separated by

  • Using Separating Funnel
    It is used to separate two immiscible liquids. Example - Oil and Water

  • By  Distillation
    In Distillation, we boil the mixture and then condensate it. It used to separate two miscible liquids. Example - Acetone and Water
  • Using Fractional Distillation
    It is a form of distillation, but in fractional distillation, the boiling points of the component mixtures are closer.  Example - Crude Oil Refining

 

Thus, two summarise

Different Methods used for Separating Mixtures

Method used are different for different types of mixture as shown below;  

Method Used

Example of Type of Mixture 

Handpicking

Separating stone from pulses

Filtration

Filter paper is used to separate sand from water

Sieving

Separate gravel from sand

Winnowing

Separate husk from grain

Evaporation

It is used to salt from water

Centrifugation

It is used to separate cream or fat from milk

Separating Funnel

It is used to separate 2 immiscible liquids like oil and water

Sublimation

It is used to separate sublimable substance from non-sublimable substance like camphor from salt

Chromatography

It is used to separate solutes which dissolve in same solvent like different color of ink

Distillation

It is used to separate acetone from water

Fractional Distillation

It is used to refine crude oil (convert crude oil into different components like petrol,diesel,kerosene)

 

 

  1. Class 9
  2. Chapter 2 Class 9 - Is Matter Around Us Pure

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo