To determine the molecular formula of the unknown compound, we first need to find the empirical formula. The empirical formula is the simplest whole number ratio of the elements in the compound. 1. Calculate the moles of each element in the compound:Moles of oxygen O : 0.50 g / 16.00 g/mol molar mass of O = 0.03125 molMoles of carbon C : 1.25 g / 12.01 g/mol molar mass of C = 0.1041 molMoles of hydrogen H : 3.25 g / 1.008 g/mol molar mass of H = 3.226 mol2. Divide each mole value by the smallest mole value to get the mole ratio:Mole ratio of O: 0.03125 / 0.03125 = 1Mole ratio of C: 0.1041 / 0.03125 = 3.33 4 round to the nearest whole number Mole ratio of H: 3.226 / 0.03125 = 103.23 104 round to the nearest whole number 3. Write the empirical formula based on the mole ratios:CHONow, we need to find the molecular formula. The molecular formula is a multiple of the empirical formula. 4. Calculate the molar mass of the empirical formula:CHO: 4 x 12.01 + 104 x 1.008 + 1 x 16.00 = 48.04 + 104.83 + 16.00 = 168.87 g/mol5. Divide the molar mass of the unknown compound by the molar mass of the empirical formula to find the multiple:Since we don't have the molar mass of the unknown compound, we cannot determine the exact molecular formula. However, we can express it as a multiple of the empirical formula:Molecular formula = CHO nwhere n is an integer representing the multiple of the empirical formula.