Separation Methods

Recrystallization

Used to separate solids when it is mostly the desired material with small amounts of impurities. This solid is placed into a solvent until all of the solvent is required to keep the solid dissolved. This is done with heat, when the solution is ready it is set to cool where pure crystals form, where Hand Separation or Filtration can be used

Gravity Separation

Used to separate solids from mechanical mixtures based on their density when mixture of high and low density solids are agitated. The more dense solids sink to the bottom where they can be collected or vice versa (ex. Gold panning)

Paper Chromatography

Used to seperate small amounts of solid in liquid solutions by placing a small sample on a piece of paper. The bottom of the paper is then placed into a solvent where it slowly rises up the paper separating the solution’s molecules. The parts of the paper containing the desired substance can then be cut out and separated

Hand Separation

When you are able to separate two or more substances using only your hands

Filtration

The separation of liquids and solids in mechanical mixtures where the solid has not been dissolved

Distillation

Used to separate two liquids by heating the solution until one of the liquid starts to evaporate where it rises into a tube, cooled, and then transferred into a container

Solvent Extraction

Used when separating two or more (ideally 2) solids in a mechanical mixture by adding a liquid that dissolves one of the solids so that the other is left behind in a pure form. When separating two liquids or a liquid and a solid, an immiscible solvent to the solvent already present is added to one of the desired substances from the solution to leave the other behind.