To calculate: take the percentages of each element given. These percentages are based off of 100%, so we can convert the percentages into grams. For example, if the compound is made up of 40.9% carbon, 4.6% hydrogen, and 54.5% oxygen, we can make these values 40.9g of C, 4.6g of H, and 54.5g of O. Divide each substance by it's molar mass. This becomes 3.41 moles of C, 4.55 moles of H, and 3.41 moles of O. Divide every value by 3.41, so they become 1 mol C, 1.33 mol H, and 1 mol O. To make every value a whole number, multiply every value by 3. This makes the empirical formula C3H4O3
