Chapter 8, Problem 8.78E

Interpretation Introduction

(a)

Interpretation:

The reason as to why it is important to specify an identity of the anion in the given case even though it is a spectator ion.

Concept introduction:

Ionic strength of a solution is calculated by adding the concentration of each ion present in the solution after multiplying it by their corresponding charges. The ionic strength of the solution is represented as,

$I=\frac{1}{2}{\displaystyle \sum _{\text{i=1}}^{\begin{array}{l}\text{number of}\\ \text{ ions}\end{array}}{m}_{\text{i}}{z}_{\text{i}}^2}$

Where,

• $m_{\text{i}}$ represents the molality of the ${\text{i}}^{\text{th}}$ ion.

• $z_{\text{i}}$ represents the charge on the ${\text{i}}^{\text{th}}$ ion.

Interpretation Introduction

(b)

Interpretation:

The expected voltage for the given electrochemical reaction is to be calculated by using the activity coefficient of ions.

Concept introduction:

Activity coefficient depends upon the charge and size of the ion, and on the properties of the solvent. Debye-Huckel limiting law, describes the relation between the ionic strength and activity coefficient of a dilute solution.