Distillation

• Simple distillation is used to separate a solvent from a solute when you also want to keep the solute.
• this is used for distillation

  
• Cold water constantly runs through the condenser which will keep the condensers internal glass tube cold
• Steps of a simple distillation reaction:

  • Heat solution in flask
  • Liquid starts to evaporate into a vapour
  • The vapour rises up the glass tube
  • The thermometer reader increases
  • Heat the solution until it boils
  • The vapour goes into the condenser
  • Turns into a liquid
  • The liquid is collected in a beaker
  • We are left with the solid in the flask and the liquid in the beaker.
• Fractional Distillation is used to seperate mixtures of different compounds
• In fractional distillation you can separate a number of liquids as long as they have different boiling points
• Fractional Distillation apparatus has one key difference, a fractionating column that contains hundreds of glass beads.
• In fractional distillation, when the thermometer temperature rises it means that a mixture of the two different vapours is passing over the thermometer
• In fractional distillation the substance with the lower boiling point rises faster
• In fractional distillation when the thermometer stop rising then we have boiled on chemical fully and have one pure chmical
• In fractional distillation after the first chemical is boiled and condensed you can then gather the second one
• In fractional distillation, it can be very hard to separate chemicals with very similar boiling points.
• In a fractionating column it is colder at the bottom which causes the chemicals with higher boiling points to condense before reaching the condenser
• Simple Distillation


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

  • Flask containing solution
  • Flask sealed with bung
  • Thermometer through bung
  • Condenser (consists of a main pipe surrounded by a cold water jacket)
  • Beaker to capture pure liquid
  • Heating device such as a bunsen burner
• Steps to simple distillation

  • Heat up solution
  • As it evaporates the vapour will rise up to the top of the flask pressure will force it down into the condenser
  • The vapour will cool and turn into liquid form, running down the pipe and into the beaker
  • As we heat the seawater we will get more and more pure liquid until all that is left in the flask is the solid
• Fractional Distillation


  Used to separate mixtures with similar boiling points
• Equipment for fractional distillation

  • Similar to simple distillation
  • Fractionating column which has lots of little glass rods for a high surface area, and a tall column so it is cooler at the top.
• Steps to fractional distillation (methanol, ethanol and propanol)

  • Heat the mixture to methanol's boiling point
  • It would rise up into the column and evaporate
  • Methanol condenses in the condenser and collects in the beaker
  • If any other substances evaporate the cool glass rods would cause them to condense and fall back into the flask
  • Change the beaker
  • Repeat for Ethanol and Propanol