In this worksheet, we will practice describing the transfer of dry solvents by cannulation and other methods, assessing hazards and common errors.
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.
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.
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
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.
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
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
When cannulation is complete, in which order should the following actions be performed?
- Open the receiving flask to the gas line.
- Remove the cannula from the receiving flask.
- Remove the cannula from the solvent.
- A2, 1, 3
- B1, 2, 3
- C2, 3, 1
- D3, 1, 2
- E1, 3, 2
When setting up a cannulation, in which order should the following actions be performed?
- Insert the cannula through the rubber septum.
- Attach a rubber septum to the solvent flask.
- Open the solvent flask to the gas line.
- A3, 1, 2
- B2, 1, 3
- C2, 3, 1
- D3, 2, 1
- E1, 2, 3