the molar mass of a compound from the following information

Calculate the molar mass of a compound from the following information. You find that the freezing point of benzene is 5.5 degrees C. You then dissolve 1.60g of the unknown compound in 22.82 mL of cyclohexane. The freezing point of the solution is found to be 2.8 degrees C. The freezing point depression constant for benzene is 4.3 degrees C/m. the density of benzene is 0.8765g/mL