Distillation

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Distillation Boiling Point
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Distillation

• Purification technique
• Used to separate components of a mixture or to
• purify an impure liquid
• Several basic types/variations
• Simple distillation
• Fractional distillation
• Simple, high vacuum distillation
• Steam distillation

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Boiling Point

• Physical property of a compound
• Used to identify an unknown

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What will we be doing?

• Based on your desk location, you will be doing
  one of the two following distillations
• Macroscale simple distillation (Procedure 1) on a
  cyclohexane/toluene mixture
• Macroscale fractional distillation (Procedure 2)
  on a cyclohexane/toluene mixture

5
After Lab

• Graph data.
• You will share your data with some of your bench
  mates then graph each set of data (a total of 2
  graphs).
• You will then assess/compare the effectiveness of
  simple and fractional distillations.

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Distillation

• Simple Distillation
• Used to separate mixture into pure components
• Works best if components boiling points differ
  by at least 75 C
• Fractional Distillation
• To be used when components boiling points are
  closer together
• Unlike simple, uses a fractioning column this
  column may be packed with material so as to
  increase the surface area for heat exchange, thus
  increasing the number of theoretical plates.
• The more theoretical plates, the better the
  purification/separation.

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Whats a plate?

• Theoretical Plate one cycle of vaporization and
  condensation

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Simple vs. Fractional

• Prediction
• Fractional distillation is a more effective
  purification
• technique than simple distillation.
• Your graphed data should show this