Simple Distillation

Simple distillation is a technique for separating a liquid from a solution containing dissolved solids, or for separating one pure liquid from a mixture of liquids.

  • For example, to separate water from a saltwater solution, we can use simple distillation. The saltwater is heated, the water vapour is collected, and then it’s cooled to form pure distilled water.

We use simple distillation when the desired liquid has a much lower boiling point, allowing it to evaporate at a lower temperature.

Procedure

Below are the steps for performing simple distillation.

1. Set up the distillation apparatus:

Diagram showing a labelled distillation apparatus with components such as the cold water inlet and outlet of the condenser, a Bunsen burner, distillate, receiving flask, thermometer, and conical flask.

  • Fill the distillation flask with the solution to be distilled

2. Heat the solution using a Bunsen burner.

  • The neck of the flask is connected to a glass tube, which is surrounded by a component known as a condenser

3. The liquid will begin to evaporate, producing a vapour.

  • The liquid will evaporate at a specific temperature, which can be monitored using the thermometer

4. The vapour will pass through the glass tube and cool as it travels through the condenser, turning back into a pure liquid.

  • The condenser remains cold due to the continuous flow of water through it

5. The pure distilled liquid will collect in the receiving flask, while the solids and liquids with a higher boiling point will remain in the distillation flask.

Safe Distillation with a Water Bath

When dealing with flammable solutions during distillation, it is important to prioritise safety. Using a Bunsen burner in this situation can present a fire or explosion risk. To reduce these risks, we can use a water bath as a heat source instead.

To perform distillation using a water bath, a container of hot water is used to heat the distillation flask containing the solution. This eliminates the need for a direct flame and provides a safer alternative for heating flammable solutions during distillation.

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