Fractional distillation and paper chromatography
Fractional distillation separates miscible liquid mixtures. The miscible liquids will have different boiling points.
- Distill off and collect the liquid with the lower boiling point first.
- Add a fractionating column to the apparatus to aid separation.
- The vapours will pass over before reaching the condenser, rising up.
- The substance with the higher boiling point will condense easily and the substance with the lower boiling point continues rising and pass over into the condenser, turning back into a liquid to be collected.
Chromatography separates components of a mixture and it works because some compounds in a mixture will dissolve better than others in the chosen solvent.
- The distance travelled relies on relative solubility. The more soluble a substance is in the solvent, the further it is carried. Separation occurs due to the different solubilities used.
- With a capillary tube, dab a spot of the solution near the bottom of a sheet of absorbent chromatography paper.
- Place the paper standing in a solvent at the bottom of a beaker.
- The solvent absorbs the paper, running through the spot of the mixture.
That is it for part 2 of separating mixtures!
Drafted by Venetia (Chemistry)