Separation of Mixture of Two (or More) Liquids

• Following are the 2 methods used to separate all the mixtures containing liquids:-
  • By the process of fractional distillation
  • By using a separating funnel

1. By the process of fractional distillation

• Fractional distillation is a process of separating two (or more) miscible liquids by distillation, the distillate being collected in fractions boiling at different temperatures.
• The more volatile liquid (having lower boiling point) distils over first, and the less volatile liquid (having higher boiling point) distils over later.
• A simple fractionating column is a tube packed with glass beads. The beads provide surface for the vapours to cool and condense repeatedly.
• For example: - Mixture of acetone and water can be separated by fractional distillation.
• Applications of Fractional Distillation

1. Fractional distillation is used to separate mixtures of miscible liquids.
2. It is used to separate crude oil “petroleum” into useful fractions such as kerosene, petrol or diesel etc.
3. It is used to separate gases of the air.

Fractional distillation

2. Separation by Separating Funnel

• A mixture of two immiscible liquids can be separated by using separating funnel.
• The separation of two immiscible liquids by a separating funnel depends on the difference in their densities.
• The denser liquid forms the lower layer whereas the lighter liquid forms the upper layer.
• For Example: - Water and Kerosene can be separated by using this method. Water being heavier forms the lower layer in the funnel whereas kerosene being lighter forms an upper layer.

Separation of immiscible liquids