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 syringe is flushed with inert gas before use.
  • BThe bottle is connected to a supply of inert gas.
  • CTubing is flushed with inert gas before use.
  • DVacuum is applied to the receiving flask.
  • EA clamp is used to secure the bottle.

Q2:

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

  • ATo lower the pressure inside the flask.
  • BTo introduce air into the flask.
  • CTo allow inert gas to leave the flask.
  • DTo allow introduced air to be flushed from the flask.
  • ETo extract liquid from the flask.

Q3:

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

  • AThree-necked flask
  • BTwo-necked flask
  • CSchlenk flask
  • DOne-necked flask
  • EDry solvent bottle

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

Q5:

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

  • AIncreasing the gas flow to the solvent flask
  • BLowering the receiving flask
  • CBriefly exposing the receiving flask to vacuum
  • DPlacing more solvent in the solvent flask
  • EUsing a shorter cannula needle

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
  • DRemoving the cannula from the solvent
  • EDisconnecting the solvent flask from the gas line

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.
  • A2, 1, 3
  • B1, 2, 3
  • C2, 3, 1
  • D3, 1, 2
  • E1, 3, 2

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, 1, 2
  • B2, 1, 3
  • C2, 3, 1
  • D3, 2, 1
  • E1, 2, 3

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