Fractional Distillation

• Simple distillation


  Used for separating out a liquid from a solution
• Equipment for simple distillation

  • Flask containing the solution/liquid mixture
  • Bung to seal the flask
  • Thermometer to measure temperature
  • Condenser with water jacket and cold water flow
  • Beaker to capture the pure liquid
  • Heating device like a Bunsen burner
• Simple distillation process


  1. Heat the mixture

  2. Liquid evaporates and rises

  3. Vapor passes through condenser

  4. Vapor cools and condenses into liquid

  5. Liquid collects in beaker
• Simple distillation can be used to separate pure water from seawater
• Fractional distillation


  Main technique used for separating mixtures of liquids
• Equipment for fractional distillation


  • Flask containing the liquid mixture
  • Fractionating column with glass rods
  • Condenser with water jacket and cold water flow
  • Beakers to collect the separated liquids
  • Heating device
• Fractional distillation process


  1. Heat the mixture to around 65°C

  2. Methanol evaporates and rises up the column

  3. Methanol condenses and collects in beaker

  4. Ethanol and propanol also partially evaporate but condense back in the column

  5. Repeat process at higher temperatures to separate ethanol and propanol
• Methanol, ethanol and propanol have similar boiling points
• The fractionating column is cooler at the top than the bottom
• The glass rods in the fractionating column provide a high surface area
• The liquids shown (methanol, ethanol, propanol) would be colorless in real life