In the reaction #2Al +6HBr -> 2AlBr_3 + 3H_2#, when 3.22 moles of #Al# reacts with 4.96 moles of #HBr#, how many moles of #H_2# are formed?

1 Answer
Feb 5, 2016

Answer:

#2.48mol#

Explanation:

The balanced chemical equation represents the mole ratio in which the chemicals react.

Since 2 moles aluminuim are required for every 6 moles of hydrogen bromide, yet we only have 3.22 moles aluminium and 4.96 moles hydrogen bromide, it implies that #HBr# will get used up first and is hence the limiting reactant, while #Al# is in excess.

So all #4.96 mol HBr# is used up and reacts with #4.96/3=1.653mol Al# to produce #4.96/2=2.48 mol H_2#.