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Lesson: Hazardous Reagents

Worksheet • 6 Questions

Q1:

When using a pyrophoric liquid, which of the following would not reduce the risk of the procedure?

  • AMeasuring the reagent volume with the smallest suitable syringe
  • BOven drying glassware before contact with the reagent
  • CUse of a cannula instead of a syringe
  • DUse of a glovebox
  • EClamping the syringe when taking up the reagent

Q2:

When diluting an acid, why is it best to add the concentrated acid to water, instead of adding water to the concentrated acid?

  • AIt is easier to control the release of heat and avoid boiling of the solution.
  • BThe acid may precipitate if only a small volume of water is present.
  • CConcentrated acid may damage the container.
  • DProducing an aqueous solution with a very low pH may cause counterions to undergo reduction-oxidation reactions.
  • EDiluting in this way prevents spillage of concentrated acid.

Q3:

When working with a large volume of pyrophoric reagent in a laboratory, which of the following is not a necessary precaution?

  • AGlovebox
  • BFace shield
  • CEmergency shower
  • DFire extinguisher
  • EOther people

Q4:

When using a pyrophoric liquid, which of the following would not reduce the risk of the procedure?

  • AUse of pentane instead of heptane as a solvent
  • BUse of n-hexyllithium instead of n-butyllithium
  • CUse of n-butyllithium instead of t-butyllithium
  • DAvoidance of synthetic clothing
  • EDiluting the material in heptane before quenching with water

Q5:

Which of the following can react in excess with aqueous potassium cyanide to produce a solution safe for disposal as non-hazardous aqueous waste?

  • ASodium hypochlorite
  • BPotassium dichromate
  • CHydrochloric acid
  • DIsopropanol
  • ESodium hydroxide

Q6:

A reaction requires the use of 50 mL of a pyrophoric liquid. Which of the following methods for transferring the liquid would produce the greatest risk?

  • AA single transfer using a 50 mL syringe
  • BA single transfer using a 100 mL syringe
  • CContinuous transfer via a cannula
  • DTwo transfers using a 50 mL syringe
  • EFive transfers using a 20 mL syringe
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