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.
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).
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.
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).
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