Chapter 12, Problem 145CP

(a)

Interpretation Introduction

Interpretation: The molality of NaCl solution should be calculated.

Concept Introduction: The boiling point is directly proportional to the molality of the solution.

  $\Delta T_b\propto m$

Or,

  $\Delta T_b=K_{b}m$

Here, $K_b$ is boiling point constant.

(b)

Interpretation Introduction

Interpretation: The freezing point of NaCl solution should be calculated.

Concept Introduction: The freezing point is directly proportional to the molality of the solution.

  $\Delta T_f\propto m$

Or,

  $\Delta T_f=K_{f}m$

Here, $K_f$ is freezing point constant.