There are different ways to separate mixtures, for example by filtration, crystallisation, distillation, or chromatography. The method chosen depends upon the type of mixture.
It is important in this core practical to use a range of equipment and methods to separate chemical mixtures. This includes the safe use and careful handling of substances.
This outlines one way to carry out the practical. Eye protection must be worn.
Aims
To investigate the composition of inks using paper chromatographyChromatography is used to separate different substances dissolved in a liquid..
Method
draw a pencil line across the chromatography paper, 1-2 cm from the bottom
use a pipette or capillary tubeGlass tubing which is very narrow inside. to add small spots of each ink to the line on the paper
place the paper into a container with a suitable solvent in the bottom
allow the solvent to move through the paper, but remove the chromatogramThe results of separating mixtures by chromatography. before the solvent reaches the top
mark the level that the solvent reached using a pencil so that you can measure the distance travelled by the solvent when it dries
allow the chromatogram to dry, then measure the distance travelled by each spot and by the solvent
Results
1. Record your results in a suitable table. For example:
