Chromatography: paper
Lesson details
Learning outcome
I can describe how paper chromatography works and use chromatograms to classify substances as pure or a mixture.
Key learning points
- Chromatography has two phases, stationary and mobile, and separation depends on the distribution between these phases.
- Both aqueous and non-aqueous solvents can be used in chromatography.
- Chromatograms can be used to identify pure and impure substances.
Keywords
Chromatography - Chromatography is a technique that separates the components of a mixture, and the results can be analysed.
Mobile phase - The mobile phase is the movement of a solvent and any dissolved components of a sample along the stationary phase in chromatography.
Stationary phase - The stationary phase is a surface along which the solvent (and any dissolved components) travels. It does not move during chromatography.
Chromatogram - A chromatogram is the resultant pattern of a sample’s components on the stationary phase after chromatography has been carried out.
Common misconception
Pupils can struggle to interpret information that contains several samples on one chromatogram.
Stress a systematic approach to interpreting chromatograms (i.e. use rulers). Live modelling this using a visualiser helps enormously.
Teacher tip
Pre-make chromatograms of pure and impure samples and challenge pupils to identify the pure components of the impure samples.
Equipment
See additional materials.
Content guidance
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the role of a solvent in a solution?
Q2.Which term describes a substance that cannot be dissolved in a particular solvent?
Q3.How does increasing the temperature of a substance generally affect the solubility of a solid in a liquid?
Q4.Match the separation technique to its most likely use.
separating a liquid from an insoluble solid
separating liquids with different boiling points
recovering a dissolved solid from a solution
removing a liquid layer from a mixture
Q5.Match the property to the type of mixture.
solution
a mixture of immiscible liquids
suspension
Q6.A solution in which more solute can be dissolved is described as ...
Assessment exit quiz
6 Questions
Q1.What is the main purpose of chromatography?
Q2.Match the following terms with their correct descriptions:
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
Q3.When analysing a chromatogram, what indicates that a substance is pure?
Q4.What is produced at the end of the chromatography process?
Q5.Order the following steps of paper chromatography correctly.
Q6.In chromatography, if a mixture contains three different components, how many distinct spots should you expect on the chromatogram?
To help you plan your 10 combined science lesson on: Chromatography: paper, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 combined science lesson on: Chromatography: paper, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 combined science lessons from the Separating substances unit, dive into the full secondary combined science curriculum, or learn more about lesson planning.