A solution of 0.1 molal urea in water has a freezing point depression of how muc
Practice Questions
Q1
A solution of 0.1 molal urea in water has a freezing point depression of how much? (K_f for water = 1.86 °C kg/mol)
0.186 °C
0.372 °C
0.186 K
0.372 K
Questions & Step-by-Step Solutions
A solution of 0.1 molal urea in water has a freezing point depression of how much? (K_f for water = 1.86 °C kg/mol)
Step 1: Identify the formula for freezing point depression, which is ΔT_f = K_f * m.
Step 2: Understand that ΔT_f is the change in freezing point, K_f is the freezing point depression constant for the solvent (water in this case), and m is the molality of the solution.
Step 3: Note the values given: K_f for water is 1.86 °C kg/mol and the molality (m) of urea is 0.1 molal.
Step 4: Plug the values into the formula: ΔT_f = 1.86 °C kg/mol * 0.1 mol/kg.
Step 5: Calculate the result: 1.86 * 0.1 = 0.186 °C.
Step 6: Conclude that the freezing point depression of the solution is 0.186 °C.
Freezing Point Depression – The decrease in the freezing point of a solvent when a solute is added, calculated using the formula ΔT_f = K_f * m.
Molality – A measure of the concentration of a solute in a solution, defined as the number of moles of solute per kilogram of solvent.
Colligative Properties – Properties that depend on the number of solute particles in a solution, not the identity of the solute.
