What is fractional distillation and how it can be used?

3 Answers
Jan 3, 2018

Two or more liquids, which have different boiling points, can be separated from their mixture by fractional distillation. For example of ethanol and water. In industrial use this is done in petroleum refineries.

Jan 3, 2018


Simple Distillation = Separating a liquid from a solution
Fractional Distillation = A mixture of liquids all separated


Simple distillation for example can result in pure water from sea water. The salt would get left in the flask and the water vapour would pass through the condenser where it turns back into a liquid, condensing. Then going to a different beaker, leaving you with pure water and salt.

Fractional Distillation for example can separate crude oil (which has lots of different liquids) as each liquid has different boiling points and evaporate at different times. The liquid with the lowest boiling point will condense and collect. Then the next liquid with the lowest boiling point will repeat, until all liquids are separated.


Any solution can be separated by distillation if each of its components is a liquid or you have solid dissolved in a liquid.


First, If each of the components in a solution is a liquid, solution can be separated by distillation.

For example, if you have a solution containing ethanol (alcohol) and water, ethanol can be separated from this mixture by [ fractional distillation ]. Ethanol reaches its boiling point and starts to evaporate but the water vapor is cooled and condensed.
This type of distillation is good for separating two or more liquids from each other have different boiling points.

Second, If you have a solid dissolved in a liquid, the liquid can be separated by distillation.

Another example, If you have salt dissolved in water, water can be separated from this solution by [ simple distillation ].
Water evaporates from the solution, but the salt does not evaporate and remains in the container.
This is good for separating a liquid from a solution of dissolved solids.