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Lesson: Hazardous Reagents

Worksheet • 6 Questions


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


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.


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


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


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


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