Answer: The molar mass of the unknown compound is 200 g/mol
Explanation:
Depression in freezing point is given by:

= Depression in freezing point
i= vant hoff factor = 1 (for molecular compound)
= freezing point constant = 
m= molality

Weight of solvent (benzene)= 0.250 kg
Molar mass of solute = M g/mol
Mass of solute = 26.7 g


Thus the molar mass of the unknown compound is 200 g/mol
Number 1 is 4.875 Number 2 is 3.47 repeating