15g of an unknown solute was dissolved in 450g of water. The resulting solution freezes at -0.340°C. What is the molar mass of the substance? Kf of water = 1.86 K kg/mol.
a) 84.1 g/mol
b) 88.3 g/mol
c) 94.5 g/mol
d) 98.7 g/mol