Chapter 12, Problem 115RQ

Interpretation Introduction

Interpretation:

All the methods used for the determination of molecular masses are to be reviewed, and the most reliable, sensitive, and convenient method is to be identified.

Concept Introduction:

The elevation in boiling point is given by the expression as follows:

$△T_b=K_{b}m$

Here, $△T_b$ is the boiling point elevation, $m$ is the molality of the solution, and $K_b$ is the molal boiling point elevation constant.

The depression in freezing point is given by the expression as follows:

$△T_f=K_{f}m$

Here, $△T_f$ is the boiling point elevation, $m$ is the molality of the solution, and $K_f$ is the molal freezing point depression constant.

The change in vapor pressure is given by the expression as follows:

$△P=X_{\text{solute}}P°$

Here, $△P$ is the change in vapor pressure, $X_{\text{solute}}$ is the mole fraction of solute, and $P°$ is the vapor pressure of the pure solvent.

The osmotic pressure is calculated by the expression as follows:

$\text{π}=M\text{R}T$

Here, $\text{π}$ is the osmotic pressure, $M$ is the molar concentration of solute, $\text{R}$ is the gas law constant, and $T$ is the temperature.