To determine the percent by mass of FeO in a 5.430-g mixture of FeO and Fe3O4 that produces 5.779 g of Fe2O3 upon reaction with excess oxygen, a balanced chemical equation is necessary. The reaction involves the conversion of FeO and Fe3O4 to Fe2O3, which can be represented by two separate equations. By applying stoichiometric calculations based on the mass of Fe2O3 produced, the amounts of FeO and Fe3O4 in the original mixture can be derived. The final calculation reveals the percent by mass of FeO in the mixture. Accurate stoichiometric analysis is crucial for determining the composition of the initial mixture.
