Chapter 13, Problem 13.12P

a)

Interpretation Introduction

Interpretation:

The concentration of species and $\text{pH}\text{of}\text{1}\text{.0}\text{mM}{\text{La}}_{\text{2}}{\left({\text{SO}}_{\text{4}}\right)}_{\text{3}}$ has to be calculated.

Concept introduction:

Davies equation:

The activity coefficient $\left(\text{γ}\right)$ of ions is given by

$\begin{array}{l}\text{log}\text{γ}\text{=}\text{-}\text{0}\text{.51}{\text{z}}^{\text{2}}\left(\frac{\sqrt{\text{µ}}}{\text{1}\text{+}\text{}\sqrt{\text{µ}}}\text{-}\text{0}\text{.3}\text{µ}\right)\\ \text{where,}\\ \text{γ}\text{-}\text{activity}\text{coefficient}\text{of}\text{ion}\\ \text{z-}\text{charge}\text{of}\text{ion}\\ \text{µ}\text{-}\text{ionic}\text{strength}\end{array}$

b)

Interpretation Introduction

Interpretation:

The actual ionic strength of the solution has to be calculated.

c)

Interpretation Introduction

Interpretation:

The fraction of Lanthanum is ${\text{La}}^{\text{3+}}$ has to be calculated.

d)

Interpretation Introduction

Interpretation:

The reason has to be given for not considering the hydrolysis of ${\text{SO}}_{\text{4}}{}^{\text{2-}}$ to give ${\text{HSO}}_{\text{4}}{}^{\text{-}}$.

e)

Interpretation Introduction

Interpretation:

The precipitation of $\text{La}{\left(\text{OH}\right)}_{\text{3(s)}}$ in the solution has to be identified.