methods of separation and purification

methods of separation and purification

1. can be separated using

   • mixures
     • when mixed without chemical combination, form
       • pure substance
         • have
           • fixed melting point
           • fixed boiling point
         • made up of one single element/compound
     • is made up of two or more substances not chemically combines

2. separating components that dissolve in same solvent

   • paper chromatography
     • result shown in chromatogram
       • use locating agent for colourless substances
       • identify components by
         • position on chromatogram
         • Rf value
           • distance travelled by substance/ distance travelled by solvent
           • remains same is under same conditions, regardless of time
       • uses:
         • determine if substance is pure
         • identify substances in sample like drugs
         • identify components in sample
         • separate components in sample

3. separating solids

   • only one soluble in solvent
     • using suitable solvent
   • only one is magnetic
     • using a magnet
   • only one sublimes
     • sublimation

4. separating solid from liquid

   • separating insoluble solid from liquid
     • filtration
       • left on the filter paper = residue// in the receiver = filtrate
     • denser solid from liquid
       • decantation
   • separating soluble solid from liquid
     • decomposes upon heating
       • crystallisation
     • does not decompose upon heating
       • evaporation to dryness

5. separating liquid from solution

   • simple distillation

6. separating liquids

   • miscible liquids
     • fractional distillation
   • immiscible liquids
     • separating funnel