Question: What is the freezing point depression of a solution if 0.5 mol of a non-volatile solute is dissolved in 1 kg of water? (Kf for water = 1.86 °C kg/mol)

Options:

1. 0.93 °C
2. 1.86 °C
3. 3.72 °C
4. 0.5 °C

Correct Answer: 0.93 °C

Solution:

Freezing point depression = Kf * molality = 1.86 * 0.5 = 0.93 °C.