A solvent is a liquid into which a solute dissolves.

When a substance dissolves in a liquid, it is described as soluble in that liquid.

Chromatography is a technique that separates a mixture into its different parts and the results can be analysed.

A chromatogram is the resultant pattern on the stationary phase after chromatography has been carried out.

To compare is to look for similarities and/or differences between two objects or ideas.

Chromatography

Science

Separating an insoluble solid from a liquid

Separating a soluble solid from a liquid

Separating pure salt from dirty rock salt

Separating liquids

Simple distillation

Distillation: practical

In the Understanding Chemical Reactions unit, pupils will build on their understanding of physical changes to learn how atoms rearrange to form new substances during chemical reactions (chemical changes).

In the key stage 2 Properties, changes and separating materials unit, pupils learnt about mixtures, including solutions, and separation techniques including filtering and evaporation.

This unit covers techniques for separating mixtures, including filtration, evaporation, distillation, and chromatography, as well as identifying pure substances. Conduct experiments safely, record observations, evaluate methods, and suggest improvements.

Separation techniques

Physical activity and equipment requiring safe use

To separate and analyse coloured mixtures.

The pattern of results obtained from chromatography is called a ...

How does a pure substance behave in chromatography?

The line on the chromatogram on which the samples are placed must be drawn in pencil because it is {{}} in the solvent.

Draw a pencil line 1 cm up from the bottom of a piece of chromatography paper.

Carefully add a small drop of your sample to the pencil line.

Place a small volume of solvent in a beaker, lower than 1cm depth.

Wind your paper on a support so that the pencil line will be above the solvent.

Lower your paper vertically into the beaker so it just touches the solvent.

Leave to allow the solvent to absorb up the paper and separate your sample.

Order these steps in performing chromatography, starting with drawing a pencil line.

Dye C contains the most soluble substance.

What can you conclude from this chromatogram?

It will sink to the bottom of the container.

If you have a mixture of sand and salt, adding water will dissolve the salt. What will happen to the sand?

A substance that dissolves in a solvent is said to be {{}} in that solvent.

Ability of a substance to take in another substance.

A substance that can dissolve in a liquid.

A substance which will be tested in an investigation.

Ability of a liquid to dissolve/mix in another liquid.

If necessary, crush the solute into small pieces.

Filter the mixture to remove any undissolved solute.

Order the following steps describing how to make a solution.

Oil and water are two liquids that cannot mix. They are said to be ...

Which of the following substances are mixtures?

Chromatography

Lesson outcome

Content guidance