1.7 describe experimental techniques for the separation of mixtures, including simple distillation, fractional distillation, filtration, crystallisation and paper chromatography

SIMPLE DISTILLATION:

- It can be used to separate liquids that contain liquids. The solution is heated until the part of the solution, with the lowest boiling point, evaporates. The vapour of that part is then cooled which turns the vapour back to a liquid. It isn't all so good though, you can only separate things with very different boiling points; for similar boiling points you need fractional distillation.


FRACTIONAL DISTALLATION:

- Is used to separate a mixture of liquids. A typical example is separating crude oil to get different fractions. It can be done in a few simple steps; if you place a fractionating column on top of a flask and heat it the different parts have different boiling points; they will eventually evaporate at different temperatures. As the substance gets hotter, the different fractions form. The lower ones first then the higher ones later, however the column is cool at the top therefore condenses into a liquid which can be collected.

FILTRATION:

- It can be used to separate an insoluble solid from a liquid. The liquid is placed onto filter paper in a funnel for the liquid to be filtered through past the solid.

CRYSALLISATION:

- This is used to separate a soluble solid from a solution; the solution is poured into an evaporation dish. The solution is then heated, to make the solution more concentrated, until crystals start to form. The solution is then removed and left in a warm area to let crystals form.

CHROMATOGRAPHY:

- It is a method used to separate components from each other. The different dyes move up the paper at different speeds, this is because of the size of the particles. Some are big and therefore stick to the paper but some are small and dissolve very quickly, allowing that component to travel quicker in the solvent.