fractional distillation

• Fractional distillation


  A process used to separate a mixture of different liquids based on their different boiling points
• Fractional distillation


  • Requires a mixture of liquids with different boiling points
  • Uses a fractionating column containing glass beads to increase the separation of the liquids
• Fractional distillation


  1. Heat the mixture

  2. Vapors with lower boiling point rise up the fractionating column first

  3. Vapors condense and drip back into the flask

  4. Repeat evaporation and condensation increases the concentration of the lower boiling point liquid

  5. Thermometer measures the temperature of the vapors

  6. When temperature is constant, collect the pure fraction of the lower boiling point liquid

  7. When temperature rises again, collect the pure fraction of the higher boiling point liquid
• If the two liquids have very similar boiling points, it is much harder to separate them and may require multiple rounds of fractional distillation
• The equipment shown is not suitable for separating very large volumes of liquid, such as when refining crude oil