aluminum metal + liquid bromine → aluminum bromide
2) Chemical equation:
Al (s) + Br₂ (l) → AlBr₃(s)
3) Balanced chemical equation:
2Al (s) + 3Br₂ (l) → 2AlBr₃(s)
4) Notes:
The most common oxidation state of aluminum is +3.
Bromine has 5 common oxidation states: -1, +1, +3, +5, and +7.
Since aluminum has a positive oxidation state, bromine must have the negative oxidation state, - 1.
In the molecular formula the valences (oxidation numbers) are exchanged as subscripts, that is the reason Al has subscript 1 (understood) while Br has subscript 3.
This is combination or synthesis reaction: two elements combine to form a new compound.
This is a very exothermic reaction which yields light (sparks) and heat.
The product, AlBr₃ is a molecular compound (not ionic).
