S124: Prep Notes

Introduction

Aluminum foil added to bromine produces heat and flames.  The effect is enhanced by red bromine fumes present in the reaction container.

2Al(s) + 3Br2(l) → 2AlBr3(s)
Note: Aluminum bromide also exists as Al2Br6.

***This demo can only be performed in CHEM 140

Supplies

Short List

  • 1000mL tall form beaker
  • Crystallization or petri dish that will fit as a lid for the container
  • Portable hood
  • Fire extinguisher
  • Safety goggle and gloves
  • Lab coat
  • Aluminum foil

Chemicals

  • Bromine
  • Sodium thiosulfate for bromine spills

Prior to Lecture  (prep time ~ 5 min.)

Assemble the following:

  • 1000mL tall form beaker
  • Crystallizing or petri dish large enough to cover beaker
  • 25mL to 50mL of bromine in a closed container.
  • Aluminum foil cut into ¼” square pieces.

To Conduct Demonstration

  1. Place the beaker on a ventilation grate.  The crystallizing or petri dish will be used as a lid on the beaker or flask.
  2. Carefully pour bromine into the container and place the dish on top.  CAUTION: Do not breathe any of the fumes!
  3. Pour about 7 pieces of aluminum foil into the beaker.  Replace the petri dish on top of the container.  This step may be repeated until one of the reagents is exhausted.

Demo Time: ~5 minute

Safety and Disposal

Intense heat and flames are produced by this reaction.  Perform this demonstration only in a hood or in an area where exhaust ventilation is provided.  Use gloves when handling bromine, and take care not to breathe any bromine fumes.  Handle hot glassware with care.