Chemistry Stoichiometry

Question

2Al+6HBr=2AlBr3+3

If 8 moles of HBr react, how many grams of Al reacted?

Answer 1

2Al(s) + 6HBr(aq) ==> 2AlBr₃ + 3H₂(g) .. balanced equation

YOU MUST START WITH THE CORRECTLY BALANCED EQUATION

Next, you use the stoichiometry (mole ratios) of the balanced equation to find the answer.

8 mols HBr x 2 mols Al / 6 mols HBr = 2.67 mols Al reacted

2.67 mols Al x 26.98 g Al / mol Al = 71.9 g Al = 70 g Al (to 1 significant figure)