Isopropyl alcohol, sold as rubbing alcohol, is composed of C, H, and O. Combustion of 0.255 g of isopropyl alcohol produces 0.561 g of CO2 and 0.306 g of H2O. Determine the empirical

Question

 Isopropyl alcohol, sold as rubbing alcohol, is composed of C, H, and O. Combustion of 0.255 g of isopropyl alcohol produces 0.561 g of CO₂ and 0.306 g of H₂O. Determine the empirical formula of isopropyl alcohol.

Answer 1

To find the empirical formula you need to convert g CO2 to moles c and then g H2O to moles H. once you have those values you will find the exact grams of C and H produced and subtract that number from the 0.255 g of isopropanol. This will give you the mass of oxygen produced from isopropanol since O2 is present and consumed in the reaction as well. Once you have the moles of O, C, and H you will divide by the smaller number of moles, which is O in this case. You will then get the ratios of carbon and hydrogen to oxygen giving you the subscripts required for each in the empirical formula. this gives C3H8O1