October's AP Problem

a)  A solution containing 3.23 grams of an unknown compound

        dissolved in 100.0 grams of water freezes at -0.97 °C. The

        solution does not conduct electricity. Calculate the molecular

        weight of the compound. (The molal freezing point depression

        constant for water is 1.86 °C /kg mol.)

b)  Elemental analysis of this unknown compound yields the

        following percentages by weight:  H= 9.74 %, C= 38.70 %

        O= 51.56 %. Determine the molecular formula for the

        compound.