Question: what is the empirical formula of a molecule containing 65.5 carbon 5.5 hydrogen and 29.0 oxygen?
Answer: The empirical formula is C₃H₃O. Assume we have 100 g of the compound. Then we have 65.5 g of C, 5.5 g of H, and 29.0 g of O. The empirical formula is C₃H₃O.