Simple Distillation

• • Ethanol obtained from distillation is not pure as it will still contain small quantity of water - some of the water in the mixture will evaporate at temperatures below its boiling point.
• Simple distillation can be used to separate:

  • a liquid from a solution (simple distillation).
  • a liquid from a mixture of two miscible (two liquids mix without forming a layer) liquids (fractional distillation).
• Simple distillation

  • Involves the evaporation of the liquid from the solution (mixture), followed by condensation.
• Simple distillation E.G.

  • Water can be separated from salt water by distillation - when salt water is heated, water evaporates and then vapour cools and condenses as passes along condenser. Pure water collects in beaker and salt doesn’t evaporate, stays behind.
• Fractional distillation

  • Involves the separation of the different liquids within the mixture - method works as liquids in solution have different boiling points. When solution is heated, liquid with lower boiling point will evaporate before the other.
• Fractional distillation E.G.

  • Water can be separated from ethanol by fractional distillation - when mixture is heated, ethanol evaporates as it has lower boiling point (78°C). Ethanol vapour cools a d condenses as passes along condenser and collects in beaker - water doesn’t evaporate as has higher boiling point (100°C).