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.
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.
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.
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.
Content guidance
- Equipment requiring safe usage.
Supervision
Adult supervision recommended.
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
Loading...