C18.4 Separating by Distilation

• Distillation is the separation technique that uses differences in boiling points to separate two or more liquids
• distillation is a way of separating a liquid from a solution by evaporating the liquid and condensing the vapour
• two types of distillation

  • fractional distillation
  • simple distillation
• simple distillation


  used to separate solvent from the solution, leaves solute behind
• in simple distillation, you achieve a pure substance such as distilled water
• apparatus used for simple distillation

  • round bottomed flask with side arms (filled with solution)
  • bunsen burner
  • thermometer
  • stopper
  • liebig condenser
  • retort stand
  • conical flask (with distillate)
• simple distillation method

  1. heat the solution in the flask. as you heat the solution in the flask, water vapour rises into he condenser
  2. the condenser is cold, so the water vapour condenses to water in it.
  3. the water drips into the beaker. this creates distilled water
  4. a residue of all other substances will remain in the flask
• fractional distillation


  used to separate two liquids
• fractional distillation is used to separate a mixture of liquids into two or more liquids by making use of their different boiling points
• apparatus used in fractional distillation

  • thermometer
  • liebig container
  • tripod
  • solution
  • ethanol
  • fractioning column with thermometer adaption
• fractioning columns contain glass beads
• fractioning distillation method

  1. heat the mixture in the flask. at 78ºC, ethanol begins to boil. some water evaporates too. a mixture of ethanol and water vapours rises up the column
  2. the vapours condense on the glass beads. the beads then heat up
  3. when the beads reach about 78ºC, ethanol vapour will no longer condense on them, only water will. water drips back down into the flask.
  4. ethanol vapour passes into the condenser. pure liquid ethanol drips into the beaker.
  5. the thermometer reading will rise above 78ºC, all ethanol is gone, stop heating
• separate a solid from its solvent using filtration