Worksheet: Dry Solvents

In this worksheet, we will practice describing the transfer of dry solvents by cannulation and other methods, assessing hazards and common errors.

Q1:

When a syringe is used to remove a liquid from a bottle or Schlenk flask containing an inert atmosphere, which of the following steps is not required?

  • AThe bottle is connected to a supply of inert gas.
  • BA clamp is used to secure the bottle.
  • CVacuum is applied to the receiving flask.
  • DThe syringe is flushed with inert gas before use.
  • ETubing is flushed with inert gas before use.

Q2:

When removing a liquid from a Schlenk flask sealed with a rubber septum, what is the purpose of the bleed needle?

  • AAllowing inert gas to leave the flask
  • BIntroducing air into the flask
  • CAllowing introduced air to be flushed from the flask
  • DExtracting liquid from the flask
  • ELowering the pressure inside the flask

Q3:

Which of the following items of glassware is least useful for performing a cannulation?

  • AOne-necked flask
  • BDry solvent bottle
  • CTwo-necked flask
  • DSchlenk flask
  • EThree-necked flask

Q4:

A student sets up a cannulation but finds there is no solvent flow. Which of the following is least likely to be the cause of the problem?

  • AThe pressure in the receiving flask is too high.
  • BThe cannula is blocked.
  • CThe cannula is not inserted into the solvent.
  • DThe pressure in the solvent flask is too low.
  • EThe receiving flask is too high.

Q5:

When cannulating a solvent, which of the following would not noticeably increase the flow rate between flasks?

  • AUsing a shorter cannula needle
  • BIncreasing the gas flow to the solvent flask
  • CLowering the receiving flask
  • DBriefly exposing the receiving flask to vacuum
  • EPlacing more solvent in the solvent flask

Q6:

What is the fastest method to stop the flow of solvent during cannulation?

  • AOpening the receiving flask to the gas line
  • BApplying vacuum to the solvent flask
  • CRaising the receiving flask
  • DDisconnecting the solvent flask from the gas line
  • ERemoving the cannula from the solvent

Q7:

When cannulation is complete, in which order should the following actions be performed?

  1. Open the receiving flask to the gas line.
  2. Remove the cannula from the receiving flask.
  3. Remove the cannula from the solvent.
  • A1, 3, 2
  • B2, 3, 1
  • C3, 1, 2
  • D2, 1, 3
  • E1, 2, 3

Q8:

When setting up a cannulation, in which order should the following actions be performed?

  1. Insert the cannula through the rubber septum.
  2. Attach a rubber septum to the solvent flask.
  3. Open the solvent flask to the gas line.
  • A3, 2, 1
  • B2, 3, 1
  • C1, 2, 3
  • D2, 1, 3
  • E3, 1, 2

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