A solution is made by dissolving 0.646 mol of nonelectrolyte solute in 791 g of benzene. Calculate the freezing point, Tf, and boiling point, Tb, of the solution. Constants may be found here.benzene C6H6 (formula) 5.12(kf value) 5.49(normal freezing point C) 2.53 (kb value) 80.1 (normal boiling point)

You have read that adding a solute to a solvent can both increase the boiling point and decrease the freezing point. A friend of yours explains it to you like this: The solute and solvent can be like salt in water. The salt gets in the way of freezing in that it blocks the water molecules from joining together. The salt acts like a strong bond holding the water molecules together so that it is harder to boil. What do you say to your friend?

Consider 2 vapor pressure curves A and B. They are the vapor pressure curves of pure benzene and a contaminated solution of benzene with a nonvolatile solute. (a) Which graph shows the vapor pressure curve for pure benzene? (b) What is the boiling point of the contaminated benzene solution? (c) Estimate the molality of the contaminated solution (k b=2.53C/m).

Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for this purpose too. Let us compare the effectiveness of equal masses of these two compounds in lowering the freezing point of water, by calculating the freezing point depression of solutions containing 200. g of each salt in 1.00 kg of water. (An advantage of CaCl2 is that it acts more quickly because it is hygroscopic, that is. it absorbs moisture from the air to give a solution and begin the process. A disadvantage is that this compound is more costly.)