Chapter 17, Problem 17.98QP

(a)

Interpretation Introduction

Interpretation:

The freezing point of $0.5mNaI$ solution should be calculated assuming that it undergoes dissociation completely without formation of ion–pair.

Concept Introduction:

Freezing point is the temperature at which liquid turns into solid.

Freezing point depression ${\text{(ΔT}}_{\text{f}}\text{)}$ is depicted as follows,

  ${\text{ΔT}}_{\text{f}}{\text{= K}}_{\text{f}}\text{m}$

Where,

  ${\text{ΔT}}_{\text{f}}-$ Change in freezing point

  ${\text{K}}_{\text{f}}-$ Molal freezing point constant

  m- molality of the solution

Molality (m) is the number of moles of solute present in one kilogram of solvent.

$\text{Molality (m) =}\frac{\text{Number}\text{of}\text{moles}\text{of}\text{solute}}{\text{1kg}\text{of}\text{solvent}}$

(b)

Interpretation Introduction

Interpretation:

The freezing point of $0.5mNaI$ solution should be calculated after addition of $Hg{I}_2$.

Concept Introduction:

Freezing point is the temperature at which liquid turns into solid.

Freezing point depression ${\text{(ΔT}}_{\text{f}}\text{)}$ is depicted as follows,

  ${\text{ΔT}}_{\text{f}}{\text{= K}}_{\text{f}}\text{m}$

Where,

  ${\text{ΔT}}_{\text{f}}-$ Change in freezing point

  ${\text{K}}_{\text{f}}-$ Molal freezing point constant

  m- molality of the solution

Molality (m) is the number of moles of solute present in one kilogram of solvent.

$\text{Molality (m) =}\frac{\text{Number}\text{of}\text{moles}\text{of}\text{solute}}{\text{1kg}\text{of}\text{solvent}}$