Question

A solution consists of 0.50 mole of CaCl2 dissolved in 100. grams of H20 at 25°C. Compared to the boiling point and freezing point of 100. grams ofH20 at standard pressure. the solution at standard pressure has
(1) a lower boiling point and a lower freezing point(2) a lower boiling point and a higher freezing point
(3) a higher boiling point and a lower freezing point(4) a higher boiling point and a higher freezing point

Answer 1

the answer is (3) higher boiling point and a lower freezing point.

these phenomena are called Boiling point elevation and Freezing point depression. The amount of solute is directly proportional to the change in freezing/boiling temperature of the solution. The more solute, the lower the freezing point and the higher the boiling point.