Chemistry - Separation Techniques

Chemistry - Separation Techniques

1. Filtration

   • To separate insoluble solid from a liquid
   • Use filter paper
   • Hot distilled water
   • Filter the mixture collecting the filtrate

2. Crystallisation

   • To separate a soluble solid from a solution
   • 1) Pour solution into an evaporating basin
   • 2) Heat the solution
   • 3) Remove from heat and slowly let the solvent evaporate
   • 4) Use a drying oven to remove the remaining water

3. Chromatography

   • Separates different solutes in a solution
   • Different solutes dissolve at different extents
   • Use pencil line as ink may confuse the colours

4. Simple distillation

   • Separate liquids from a solution
   • 1) Solution is heated
   • The part of the solution which has the lower boiling point will evaporate first
   • 2) The rest stays in the beaker
   • You can only do this if the two liquids have very different boiling points

5. Fractional Distillation

   • Do this for a mixture of liquids with similar boiling points
   • When the temperature is right the first liquid will reach the top of the column
   • The top of the column is coldest
   • When you want the second liquid raise the temperature