Interpreting chromatograms
I can analyse chromatograms both qualitatively and quantitatively.
Interpreting chromatograms
I can analyse chromatograms both qualitatively and quantitatively.
Lesson details
Key learning points
- Chromatograms can identify unknown substances by qualitative visual comparison or quantitatively by Rf value comparison.
- Appropriate equipment should be employed when using chromatograms to identify unknown substances in a mixture.
- An appropriate number of significant figures should be used in calculations.
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 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.
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 (i.e. use rulers). Live model this (using a visualiser helps enormously).
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
Exit quiz
6 Questions
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