The freezing point depression of a solution made by the addition of a nonionic unknown solute (i=1) to benzophenone (solvent) was used to determine the molar mass of the unknown. Data were collected for a solution containing 500 g of benzophenone with 5.9 g of the unknown solute added. The Kf of benzophenone is 9.8 °C/m. The freezing point of the benzophenone was determined to be 7.19 °C. The freezing point of benzophenone with the unknown added (solution) was determined to be -0.98 °C. [1000 g = 1 kg]
(i) Determine the freezing point depression, ΔTf
(ii) Calculate the Molality of the solution, m
(iii) How many moles of the Unknown solute were used
(iv) Calculate the molar mass or molecular weight of the nonionic unknown