the answer is not c8h11o6 orc7h6o4

When 28.4g of an organic compound known to be 55.81%C,7.0%H, and 37.17%O by mass is dissolved in 836.6g of water, the freezing point is 0.489C. The normal freezing point of water is 0C. What is the molecular formula for the organic compound? Assume that the organic compound is a molecular solid and does not ionize in water. Kf values for various solvents are given in the colligative constants table