Chromatography is a technique that separates the components of a mixture, and the results can be analysed.

The mobile phase is the movement of a solvent and any dissolved components of a sample along the stationary phase in chromatography.

The stationary phase is a surface along which the solvent (and any dissolved components) travels. It does not move during chromatography.

A chromatogram is the resultant pattern of a sample’s components on the stationary phase after chromatography has been carried out.

Chromatography: paper

Combined science

Separating mixtures (including formulations)

Solutions

Filtration

Crystallisation

Comparing types of chromatography: including gas chromatography

Interpreting chromatograms

Chromatography: separating a mixture of inks

Distillation: simple distillation

Distillation: separating a mixture of inks

Distillation: fractional distillation

Potable water

In the Making Salts unit, pupils will build on their understanding of separation techniques to learn about the process of making salts and writing balanced chemical equations.

In the Separation Techniques unit, pupils learned about various methods for separating mixtures, including filtration, evaporation, distillation, and chromatography.

This unit explores purification techniques, including filtration, crystallisation, and distillation. It explains formulations, uses chromatographic methods to identify pure and impure substances, and interprets chromatograms with Rf values. The emphasis is on accurate measurements.

Separating substances

Physical activity and equipment requiring safe use

to observe the colour changes in a mixture

What is the main purpose of chromatography?

a technique that separates the components of a mixture

the movement of a solvent and dissolved sample components

a surface along which the solvent travels and does not move

the resultant pattern of a sample’s components after chromatography

Match the following terms with their correct descriptions:

spots spread evenly across the chromatogram

When analysing a chromatogram, what indicates that a substance is pure?

What is produced at the end of the chromatography process?

Wait for the solvent to travel up the paper.

Order the following steps of paper chromatography correctly.

In chromatography, if a mixture contains three different components, how many distinct spots should you expect on the chromatogram?

What is the role of a solvent in a solution?

Which term describes a substance that cannot be dissolved in a particular solvent?

How does increasing the temperature of a substance generally affect the solubility of a solid in a liquid?

separating a liquid from an insoluble solid

separating liquids with different boiling points

recovering a dissolved solid from a solution

Match the separation technique to its most likely use.

Match the property to the type of mixture.

A solution in which more solute can be dissolved is described as ...

Chromatography: paper

Lesson outcome

Content guidance