What is the molar m of the unkn compound if it has a freezing point of -6.6 oC...?

A solution is prepared by dissolving 3.34 g of an unknown nonelectrolyte in 14.00 g of cylcohexane (tf = 6.6 oC and kf = 20.0 oC/m). What is the molar m of the unknown compound if the solution has a freezing point of -6.6 oC?