Combustion of a 0.9835g sample of a compound containing only carbon, hydrogen, and oxygen produced 1.900g of CO2 and 1.070g of H2O. What is the empirical formula of the compound?
the combustion reaction is CHO + O2 = H20 + CO2 The amount of carbon can be determined by the amount of carbon dioxide. moles C = 1.90 g CO2 / 44 g/mol CO2 = 0.0432 moles C = 0.5182 g C The amount of H can be derived from the amount of water mole H = 1.070 g H2O / 18 g / mol H2O = 0.0594 g H
grams O is 0.9835 - 0.5182 g C - 0.0594 g H = 0.4059 g O.
transforming the determined masses to moles and dividing each to the least among the three, the empirical formula is C2H2O
