If the freezing point of a solution is -5°C, what is the molality of the solutio
Practice Questions
Q1
If the freezing point of a solution is -5°C, what is the molality of the solution if the freezing point depression constant (Kf) is 1.86°C kg/mol? (2022)
1.34 m
2.68 m
0.5 m
3.72 m
Questions & Step-by-Step Solutions
If the freezing point of a solution is -5°C, what is the molality of the solution if the freezing point depression constant (Kf) is 1.86°C kg/mol? (2022)
Step 1: Understand the formula for freezing point depression, which is ΔTf = Kf * m.
Step 2: Identify the values given in the problem. The freezing point depression (ΔTf) is -5°C and the freezing point depression constant (Kf) is 1.86°C kg/mol.
Step 3: Substitute the values into the formula. We have -5 = -1.86 * m.
Step 4: To find m (molality), rearrange the equation. This means we need to divide both sides by -1.86.
Step 5: Calculate m by dividing 5 by 1.86. So, m = 5 / 1.86.
Step 6: Perform the calculation to find the value of m, which is approximately 2.68 m.
Freezing Point Depression – The decrease in the freezing point of a solvent when a solute is added, which is directly proportional to the molality of the solution.
Molality Calculation – The calculation of molality (m) using the formula ΔTf = Kf * m, where ΔTf is the change in freezing point.
