Chapter 19, Problem 76A

Interpretation Introduction

Interpretation : The solutions of salts that hydrolyze water do not have a pH of 7 to be explained.

Concept Introduction : One of the products of a neutralization reaction is salt. Salt constitutes a cation from a base and an anion from an acid. They are neutral in solution form.

Answer to Problem 76A

The solutions of salts that hydrolyze water do not have a pH of 7 because the solution is either acidic where the pH is less than 7 or the solution is basic where the pH is greater than 7.

Explanation of Solution

When salt is dissociated, its cations or anions either remove hydrogen ions or give hydrogen ions to water.

Positive ions in salts that form acidic solutions cause them to release hydrogen ions into the water.

Negative ions in salts that create basic solutions draw hydrogen ions from water.

Acidic solutions are produced from a strong acid and a weak base.

In the acidic solution, the pH will be less than 7.

The basic solutions are formed from a weak acid and a strong base.

In the basic solution, the pH will be greater than 7.

There is no solution formed at pH 7.