Chapter 18, Problem 18.93P

(a)

Interpretation Introduction

Interpretation:

The higher $\text{pH}$ of the solution has to be identified from the given pairs, $\text{0}{\text{.2 M Ni(NO}}_{\text{3}}{\text{)}}_{\text{2}}\text{ or 0}{\text{.2 M Co(NO}}_{\text{3}}{\text{)}}_{\text{2 }}$.

Concept introduction:

Increasing acid strength:

Acids strength is mainly depending on the dissociation of ions, strong acids dissociates completely and weak acid dissociate slightly.

The acid strength is depending on the ${\text{K}}_{\text{a}}$ value, if the ${\text{K}}_{\text{a}}$ value is larger the stronger the acid and it is lower $\text{pH}$. if the ${\text{K}}_{\text{a}}$ value is small the weaker the acid and it is higher $\text{pH}$.

(b)

Interpretation Introduction

Interpretation:

The higher $\text{pH}$ of the solution has to be identified from the given pairs, $\text{ 0}{\text{.35 M Al(NO}}_{\text{3}}{\text{)}}_{\text{3}}\text{ or 0}{\text{.35 M Cr(NO}}_{\text{3}}{\text{)}}_{\text{3}}$.

Concept introduction:

Increasing acid strength:

Acids strength is mainly depending on the dissociation of ions, strong acids dissociates completely and weak acid dissociate slightly.

The acid strength is depending on the ${\text{K}}_{\text{a}}$ value, if the ${\text{K}}_{\text{a}}$ value is larger the stronger the acid and it is lower $\text{pH}$. if the ${\text{K}}_{\text{a}}$ value is small the weaker the acid and it is higher $\text{pH}$.