Chromatography

• Aim: to investigate how paper chromatography can be used to investigate and tell the difference between different coloured substances
• ste 1: draw a pencil line across the chromatography paper, 1-2cm from the bottom “
• step 2 : use a pipette or a capillary tube to add small spots of ink to the line on the paper
• step 3: place the paper into a container with a suitable solvent in the bottom
• step 4: allow the solvent to move through the paper but remove the chromatogram before it reaches the top
• step 5: allow the chromatogram to dry, then measure the distance travelled by each spot and by the solvent
• step 6: Calculate the Rf value of each spot:

  distance travelled by substance/ distance travelled by solvent