What is fractional distillation with example?

Fractional distillation is a method used to separate a mixture of liquids based on their different boiling points. A common example is separating petroleum into petrol, diesel, kerosene, etc.

How Fractional Distillation Works

1. The mixture is heated in a container.
2. As the temperature rises, the liquid with the lowest boiling point evaporates first.
3. Vapors go through a fractionating column where they cool and condense at different heights based on their boiling points.
4. The separated liquids are collected in separate containers.

Example of Fractional Distillation

Crude oil is a mixture of hydrocarbons. It is heated and passed into a fractionating column.

• Petrol comes out near the top (low boiling point).
• Diesel is collected in the middle.
• Lubricating oils and bitumen settle at the bottom (high boiling points).

Uses of Fractional Distillation

• Purifying alcohol.
• Separating air into nitrogen and oxygen.
• Oil refining industry.