In order to determine the oxidation state of iron in both the reactant and product, we first need to write the balanced chemical equation for the oxidation of iron to form iron III oxide. The equation is:4 Fe + 3 O2 2 Fe2O3Now, let's determine the oxidation state of iron in both the reactant and product:1. In the reactant, iron Fe is in its elemental form, which means its oxidation state is 0.2. In the product, iron III oxide Fe2O3 , the oxidation state of oxygen is -2 as it is in most compounds . Since there are three oxygen atoms in the compound, the total negative charge contributed by oxygen is -6. In order to balance the charge in the compound, the two iron atoms must have a combined positive charge of +6. Therefore, the oxidation state of each iron atom in Fe2O3 is +3.So, the oxidation state of iron in the reactant is 0, and in the product, it is +3.