There are three different oxides of iron: FeO, Fe2O3 (hematite), and Fe3O4 (magnetite). Assuming that the iron oxide formed in this problem is Fe2O3, which is the most common form of iron oxide, the calculations are as follows:
Balanced chemical equation:
4Fe + 3O2 --> 2Fe2O3
i 2 0.75 0
c 1 0.75 0.5
e 1 0 0.5
Moles Fe = 112g /55.845 = 2
Moles O2 = 24/32 = 0.75
The reaction, with an excess of 1 mol Fe, produced 0.5 moles or 0.5 moles(159.69g/mol) = 79.845 grams of Fe2O3.