distillation/fractional

• Separating a liquid and soluble solid from a solution


  1. Heat solution

  2. Liquid evaporates producing vapour

  3. Vapour passes through condenser

  4. Vapour condenses into pure liquid

  5. Solid solute left behind
• Separating a solution

  • Water from a solution of salt water
• The solution is heated and a liquid evaporates producing a vapour which rises through the neck of the round-bottomed flask
• For saltwater, the water would boil at 100 oC
• The vapour passes through the condenser, where it cools and condenses, turning into the pure liquid that is collected in a beaker
• After all the liquid is evaporated from the solution, only the solid solute will be left behind
• Simple Distillation


  1. Used to separate a liquid from a solution or a pure liquid from a mixture of liquids

  2. Heat solution till liquid evaporates out producing a vapour which rises to top of flask

  3. Due to pressure, vapour forced out through condenser where it cools and condenses into pure liquid collected in beaker

  4. After all water evaporated from solution, only the solid solute will be left behind
• Simple Distillation


  • Separating pure water from seawater
• Simple Distillation


  • Water comes out near top next to thermometer
  • Water goes in at the bottom of the condenser near collecting beaker
  • Condenser has a stream of continuously flowing cold water
• Distillation is a problem because we can only use it to separate things with different boiling points, because if you go above the substance with highest boiling point they will mix
• Fractional Distillation


  1. Solution heated to temp of substance with lowest boiling point, this substance will evaporate first

  2. Vapour will pass through condenser where it cools and condenses into liquid that collects in beaker

  3. Other liquids may evaporate but the fractionating column (with glass rods) is cooler at top so liquid will only go partly up before condensing

  4. Repeat steps for all liquids only modifying their temps
• Fractional Distillation


  • Used for separating mixtures of liquids or liquids that are miscible (when 2 liquids fully mix leaving no distinct layer between them)
  • Thermometer used to monitor temperature
  • Condenser used to cool and condense vapours
  • Electric heater used instead of Bunsen burner as ethanol is flammable
• Fractional distillation is used for separating mixtures of liquids or liquids that are miscible (when 2 liquids fully mix leaving no distinct layer between them)