What is the freezing point depression of a solution containing 3 moles of KCl in

₹0.0

Question: What is the freezing point depression of a solution containing 3 moles of KCl in 1 kg of water? (Kf for water = 1.86 °C kg/mol) (2022)

Options:

Correct Answer: 5.58 °C

Exam Year: 2022

Solution:

Freezing point depression = i * Kf * m = 3 * 1.86 * 3 = 5.58 °C (i = 2 for KCl).

What is the freezing point depression of a solution containing 3 moles of KCl in 1 kg of water? (Kf for water = 1.86 °C kg/mol) (2022)

What is the freezing point depression of a solution containing 3 moles of KCl in 1 kg of water? (Kf for water = 1.86 °C kg/mol) (2022)

Step 1: Identify the formula for freezing point depression, which is ΔTf = i * Kf * m.
Step 2: Determine the van 't Hoff factor (i) for KCl. Since KCl dissociates into K+ and Cl-, i = 2.
Step 3: Find the Kf value for water, which is given as 1.86 °C kg/mol.
Step 4: Calculate the molality (m) of the solution. Since there are 3 moles of KCl in 1 kg of water, m = 3 moles/kg.
Step 5: Substitute the values into the formula: ΔTf = 2 * 1.86 °C kg/mol * 3 m.
Step 6: Perform the multiplication: ΔTf = 2 * 1.86 * 3 = 11.16 °C.
Step 7: The freezing point of the solution is lowered by 11.16 °C.

No concepts available.