How will you separate the components of a mixture containing two miscible liquids?
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Solution
The components of a mixture containing two miscible liquids can be separated by distillation.
Miscible liquids: A mixture of two or more liquids that intermix with each other to form a homogeneous solution. Example: a mixture of ethanol and water
Distillation: It is a technique for separation of a mixture of two miscible liquids which boil without decomposing (as that will change the substance to be separated) and have sufficient difference in the boiling points (i.e.; more than 25 K)
The principle involved in the separation of mixture:
The component with a lower boiling point evaporates first and leaves the mixture due to the sufficient difference in their boiling points.
Set-up for the distillation:
Mixture of miscible liquids is poured into a round bottom flask held by a clamp and placed on the burner.
The mouth of the round bottom flask is fitted with a thermometer and a water condenser called Liebig's condenser.
The inner of the condenser is connected to the flask for the liquid to pass through and cool water is circulated through its outer tube to condense the vapours coming from the round bottom flask.
An empty measuring cylinder is placed at the other end of the condenser to collect the liquid.
Process of distillation:
The mixture is heated gradually.
The component of the mixture with a lower boiling point starts to form vapours as the temperature at which it boils is attained first.
The vapours of this component condense when passed through the condenser and are collected in the measuring flask.
The component two remains behind in the round bottom flask.
Fractional distillation: It is a technique for the separation of a mixture of two miscible liquids which have comparable boiling points i.e.; the difference between their boiling points is less than 25 K.
