Chemistry......PLEASE HELP!!!!?

Elemental ysis endicates the simplest formula of an unknown is C2H4O. When 0.775g of the compound is dissolved in 50g of benzene (C6H6), the solution freezes at 5.06degrees Celcius. What are the molecular weight and the molecular formula of the compound? THe freezing point of pure benzene is 5.48 degrees Celcius and its Kf is 5.12 degrees C/m.