A solution made by dissolving 150.0 g of an unknown compound in 365.0 mL of benzene to make a solution which has a freezing point 18.6°C lower than that of pure benzene. Kf for benzene is 5.12°C/m and the density of benzene is 0.877 g/mL. The solution contains 1.16 moles of the unknown. What is the molar mass of the unknown compound?