1. Metallic aluminum burns with bromine according to the following balanced equation: 2 Al (s) + 3 Br2 (l) → 2 AlBr3

Question

Determine the mass of AlBr3 that will be produced from the reaction of 100. g aluminum and excess of bromine.

Answer 1

2Al(s) + 3Br₂(l) ==> 2AlBr₃

Since Br₂ is in excess, the theoretical yield of AlBr₃ will be dependent only on the amount of Al present. Using dimensional analysis along with the stoichiometry of the balanced equation, we can calculate the mass of AlBr₃ that will be produced:

100 g Al x 1 mol Al/26.98 g x 2 mol AlBr₃/2 mol Al x 267 g AlBr₃/mol = 990 g AlBr₃ (to 3 significant figures)