Calculate the freezing point and boiling point of a solution containing 16.2 g of naphthalene (C10H8) in 105.0 mL of benzene. Benzene has a density of 0.877 g/cm3.
1. Calculate the freezing point of a solution. (Kf(benzene)=5.12∘C/m.)
2. Calculate the boiling point of a solution. (Kb(benzene)=2.53∘C/m.)
1 Answer

(16.2 g C10H8) / (128.1705 g C10H8/mol) / (105.0 mL x 0.000877 kg/mL) = 1.37 mol/kg = 1.37 m
(5.12∘C/m) x (1.37 m) + 5.49∘C = 1.52∘C
(2.53∘C/m) x (1.37 m) + 80.1∘C = 83.6∘C