Zusammenfassung der Ressource
Chromotography
- It is used to identify substances in a mixture
- Different substances wash
through wet filter paper at
different rate
- Method:
- 1. Draw a pencil baseline on filter
paper and put dots of each mixture
on the line
- 2. Roll up the piece of paper and put
it in a beaker containing water
- 3. you must make sure the
baseline is kept above water level
- 4. The water will seep up the
paper, taking the water with it
- 5. The different chemicals
on the paper separate
different spots on the paper
- 6. The result of the
chromatography test is
called a chromatogram
- A Chromatogram with 4 spots
means there is at least 4
different substances in the sample
mixture
- Uses for this:
- to separate out the mixture of
colouring agents in food
- You can calculate the Rf value for
each chemical
- Rf= Distance travelled by substance (e.g.
food colouring) /distance travelled by
solvent (e.g. water)