1.0 gram of an unknown organic molecule is dissolved in 50.0 grams of benzene. Determine the molecular mass of the unknown if this solution freezes at 4.5\({}^{\rm o}\)C. Assume the freezing point constant of benzene is 5.0\({}^{\rm o}\)C per molal, and the freezing point of benzene is 5.5\({}^{\rm o}\)C. Give your answer to the nearest whole number in grams per mole.
100