Worksheet: Distillation

In this worksheet, we will practice describing the purification of solvents and other liquids by distillation, assessing hazards and common errors.


What is the main reason for adding a stir bar to the pot still in a distillation?

  • AStirring the liquid ensures the vapor composition is uniform.
  • BStirring the liquid allows it to be heated more uniformly.
  • CStirring the liquid increases the rate of boiling, making the distillation more efficient.
  • DStirring the liquid reduces the risk of bumping.
  • EStirring the liquid prevents phase separation as the temperature increases.


How could elastic bands be used in a vacuum distillation?

  • ATo prevent breakage by securing the apparatus in an upright position
  • BTo improve the condensation rate by insulating the condenser joints
  • CTo secure the thermometer in the correct position near the opening of the condenser
  • DTo improve the vacuum seal by applying tension to the condenser joints
  • ETo prevent water leakage by securing the condenser tubes in the correct positions


When performing a vacuum distillation, why is it often advantageous to use a pig adapter?

  • ASamples of the distillate can be collected without releasing the vacuum.
  • BA larger volume of distillate can be collected.
  • CThe distillate can be protected from contamination if bumping takes place.
  • DMultiple fractions can be collected without releasing the vacuum.
  • EMultiple fractions can be collected and stored at different vacuum pressures.


Which of the following precautions is most important for ensuring that the apparatus for a vacuum distillation is well sealed?

  • AThe condenser is maintained at a low temperature.
  • BElastic bands are stretched between the still head and condenser.
  • CThe ground glass joints are secured with Keck clips.
  • DThe ground glass joints are greased.
  • EThe receiving flask is supported by a jack.


Which of the following pieces of apparatus is not typically used in distillations?

  • AThermometer
  • BHotplate
  • CCondenser
  • DFunnel
  • EKeck clip


Which of the following pieces of apparatus is not used in distillations?

  • A
  • B
  • C
  • D
  • E


A student sets up a vacuum distillation using the glassware shown, in addition to other apparatus. Some connectors and other parts of the glassware are labeled.

5 1 0 9 1 1 3 2 6 7 8 1 2 1 4

To which position should the vacuum pump be connected?

Which positions should be supported by a clamp?

  • A 3 and 5
  • B 6 and 10
  • C 3 and 10
  • D 4 and 5
  • E 4 and 6

To which position should the pig adapter be attached?

To which female connectors would the attachment of Keck clips be potentially hazardous?

  • A 4 and 5
  • B 6 and 9
  • C 6 only
  • D 4 and 9
  • E 5 only

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