The Freezing Point of Pure Benzene Was Measured as 5

Multiple Choice

The freezing point of pure benzene was measured as 5.49 °C.With the same benzene and same equipment,the freezing point of a solution containing 6.582 g of an unknown molecular compound (sold in the store as "moth crystals") in 100.203 grams of benzene was found to be 3.48 °C.The cryoscopic constant,K_f,for benzene is 5.12 °C kg/mole.Calculate the molar mass weight of the unknown.

A) 37.5 g/mol
B) 16.7 g/mol
C) 96.6 g/mol
D) 70.4 g/mol
E) 167 g/mol