Bromine Aluminum Reaction

Aluminum bromide can be formed by reacting liquid bromine with solid aluminum. A salt is formed, which has an ionic character to it.

Key Takeaways

  • The following reaction occurs: 2 Al(s) + 3 Br2(l) ==> 2 AlBr3(s)
  • The reaction is highly exothermic so that a huge part of the reactants is lost. Sparks from burning aluminum and bromine vapor are everywhere!

Materials needed

  • A few milliliters of liquid bromine
  • Small chunks of aluminum or aluminum foil
  • Test tube
  • Lab stand

How to react Bromine with Aluminum

Only perform this experiment in a fume hood or outside! A big amount of bromine vapor is released – wear proper safety equipment!

  1. Add 2-3 milliliters of liquid bromine to a test tube
  2. When ready, add small chunks or aluminum foil to the test tube
  3. The reaction will start after serval seconds to minutes

Aluminum and Bromine chemical Reaction

2 Al(s) + 3 Br2(l) ==> 2 AlBr3(s)

“Aluminum bromide is hygroscopic and fumes in air, forming a white cloud that looks orange because it is mixed with bromine vapor. Aluminum has a Pauling electronegativity of 1.5 and bromine has an electronegativity of 2.8. The resulting electronegativity difference of 1.3 for the aluminum-bromine bond falls well within the commonly accepted range for polar covalent bonds. So this is an example of a compound between a metal and a non-metal in which the bonds have a great deal of covalent nature.Since the aluminum bromide produced in this reaction is formed from elements in their standard states, this is an example of a formation reaction. The heat of formation of aluminum bromide is -526 kJ/mol.This accounts for the exothermic nature of the reaction. Since aluminum bromide is electron deficient, it is a Lewis acid and reacts strongly with water, which accounts for the way it fumes when exposed to the moisture in air. ” Source

Experiment Video