The solvent front is the furthest distance the solvent travels along the stationary phase during chromatography.

The sample line is where the sample undergoing chromatography is placed on the stationary phase.

The Rf value is the retention factor - a ratio describing the distance a component of a sample travelled in relation to the distance the solvent travelled under the same conditions.

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

Interpreting chromatograms

Combined science

Separating mixtures (including formulations)

Solutions

Filtration

Crystallisation

Chromatography: paper

Chromatography: separating a mixture of inks

Distillation: simple distillation

Distillation: separating a mixture of inks

Distillation: fractional distillation

Potable water

Wastewater treatment

Water sample analysis: pH

Water sample analysis: dissolved solids

Water sample analysis: distillation

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

The pattern that forms as a result of chromatography is called a ...  

the furthest distance the solvent travels along the stationary phase

where the sample is placed on the stationary phase

a ratio of the distance a component of a sample travels vs the solvent

Which of the following pieces of apparatus and equipment is **not** essential for chromatography?

How can chromatograms be used to identify if a sample is a mixture?

A vertical analysis of a sample’s chromatogram can visually determine if a sample is pure or a mixture. This is known as {{}} analysis.

Given a solvent front at 7.0 cm and a substance spot at 2.3 cm on a chromatogram, calculate the Rf value.

a pure substance made of one kind of atom

True or false? All pure substances are elements.

True or false? If something is not pure, it is a mixture.

True or false? All mixtures can be separated into their individual components through physical processes.

to find out the composition of a substance

What is the purpose of chemical analysis?

Solubility is a measure of how well a substance can {{}} in a solvent.

Interpreting chromatograms

Lesson outcome