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Chemistry LibreTexts

Reaction Between Aluminum and Bromine

Chemical Concepts Demonstrated

  • Metal/nonmetal chemistry
  • Chemistry of aluminum

Demonstration
  • Drop pieces of aluminum foil into a beaker of liquid bromine.
albr3.gif

Observations

The reaction begins and builds up heat.  This heat causes the aluminum to melt and float on top of the liquid bromine (which is producing a cloud of vapor because the heat is also boiling it).  Wherever the two elements meet, sparks, heat, and light are given off.

Explanation (including important chemical equations)

The reaction between aluminum and bromine is very exothermic (DHo = -1022 kJ).  This drives the entire process, and energy is given off in the form of light and heat:

2 Al (s) + 3 Br2 (l) --> 2 AlBr3 (s)

The product of this reaction is a molecular solid with the formula Al2Br6, but the formula is often written as AlBr3.

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