What mass of aluminum is required if 40.0 grams of iron (III) oxide is to be completely consumed in the reaction #Fe_2O_3(s) + 2Al(s) -> 2Fe(l) + Al_2O_3(s)#?
The balanced chemical equation represents the mole ratio in which chemicals combine.
Hence 1 mole iron(III)oxide requires 2 moles aluminium.
Therefore by ratio and proportion,
This corresponds to a mass of :