In this example problem we'll use dimensional analysis and stoichiometry to convert from mass of one substance to mass of another substance in a chemical reaction. Our problem reads, "How many grams of carbon monoxide are produced from 46.5 grams ilmenite according to the equation?" We will start our dimensional analysis with 46.5 grams of ilmenite and need to convert to grams of carbon monoxide. Anytime we convert from one substance to another in dimensional analysis, we can usually do it in moles. So first we'll convert from grams of ilmenite to moles of ilmenite using its molar mass. Now that we're in moles of ilmenite, we can convert from moles of ilmenite to moles of carbon monoxide using the coefficients in the balanced chemical equation. This step is the stoichiometry. We need one mole of ilmenite for every three moles of carbon monoxide according to the balanced chemical equation. Then we can convert from moles of carbon monoxide to grams of carbon monoxide using its molar mass. Completing the calculation, we should get 25.8 grams of carbon monoxide.