Answer:
4 Fe + 3 O2 = 2 Fe2O3
Step-by-step explanation:
In order to balance the equation, there should be equal number of iron atoms (Fe) and oxygen atoms (O2) in Iron(III) oxide (Fe2O3).
Since there are two atoms of Oxygen in 1 oxygen molecule and 3 atoms of Oxygen in 1 Iron Oxide, the least common multiples of the total oxygen atoms which would equal each other is 6 atoms of Oxygen. This results in 3 molecules of O2 and 2 molecules of Fe2O3.
In order to balance out the amount of iron in iron oxide, you must then calculate the total iron atoms in iron oxide; since there are 2 atoms of Fe in each molecule of Iron Oxide and there is 2 molecules of Fe2O3, the total is 2*2 = 4 atoms of iron, Fe.
In order to get 4 atoms of iron from molecules of Fe, you need 4 molecules of Fe, since each molecule contains 1 Fe.