The multistep smelting of ferric oxide to form elemental iron occurs at high temperatures in a blast furnace. In the first step, ferric oxide reacts with carbon monoxide to form Fe₃O.₄ This substance reacts with more carbon monoxide to formiron(II) oxide, which reacts with still more carbon monoxide to form molten iron. Carbon dioxide is also produced in each step. (a) Write an overall balanced equation for the iron-smelting process.
(b) How many grams of carbon monoxide are required to form 45.0 metric tons of iron from ferric oxide?