Chromatography: separating a mixture of inks
I can identify the composition of inks using paper chromatography.
Chromatography: separating a mixture of inks
I can identify the composition of inks using paper chromatography.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Chromatograms can identify unknown substances through comparison or Rf values.
- Appropriate equipment should be used during comparisons, and calculations should consider significant figures.
- A fair comparison of chromatograms depends on stationary and mobile phase choices, sample concentration and temperature.
- Chromatograms can be used to identify pure and impure substances.
Keywords
Solvent front - The solvent front is the furthest distance the solvent travels along the stationary phase during chromatography.
Sample line - The sample line is where the sample undergoing chromatography is placed on the stationary phase.
Rf value - The Rf value is a ratio describing the distance a component of a sample travelled, in relation to the distance the solvent travelled under the same conditions.
Chromatogram - A chromatogram is the resultant pattern 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 - use rulers. Live model this - using a visualiser helps enormously.
To help you plan your year 10 chemistry lesson on: Chromatography: separating a mixture of inks, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 chemistry lesson on: Chromatography: separating a mixture of inks, 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 chemistry lessons from the Separating substances unit, dive into the full secondary chemistry curriculum, or learn more about lesson planning.
Equipment
See additional materials.
Content guidance
- Risk assessment required - chemicals
- Risk assessment required - equipment
Supervision
Adult supervision required