Chapter 9.6, Problem 9.75QAP

Interpretation Introduction

Interpretation:

The freezing point can be calculated by using the formula for depression in freezing point. Depression in freezing point is a colligative property which depends on the number of moles of solute.

Concept introduction:

Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent. The freezing point of solution is lower than that of the pure solvent and is directly proportional to the molality of the solute.

$\Delta T_f=T_f(solvent)-T_f(solution)=K_f\times m$

where $\Delta T_f$ is the freezing point depression, $T_f(solution)$ is the freezing point of the solution, $T_f(solvent)$ is the freezing point of the solvent, $K_f$ is the freezing point depression constant, and m is the molality.

Interpretation Introduction

To determine: the freezing points for the given solutions.