Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

Lesson: Distillation

In this lesson, we will learn how to describe the purification of solvents and other liquids by distillation, assessing hazards and common errors.

Worksheet • 7 Questions

Q1:

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

  • A
  • B
  • C
  • D
  • E

Q2:

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

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 4 and 9
  • D 6 only
  • E 5 only

Q3:

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

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

Q4:

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

  • AMultiple fractions can be collected without releasing the vacuum.
  • BMultiple fractions can be collected and stored at different vacuum pressures.
  • CA larger volume of distillate can be collected.
  • DThe distillate can be protected from contamination if bumping takes place.
  • ESamples of the distillate can be collected without releasing the vacuum.

Q5:

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

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

Q6:

How could elastic bands be used in a vacuum distillation?

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

Q7:

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

  • AFunnel
  • BKeck clip
  • CHotplate
  • DCondenser
  • EThermometer
Preview

Related Lessons