Chapter 19, Problem 83A

a.

Interpretation Introduction

Interpretation : The concentration of hydrogen ion and hydroxide ion in a neutral solution is to be compared and explained.

Concept Introduction : A hydrogen ion added to a water molecule transforms it into a hydronium ion. A hydroxide ion is created when a water molecule loses one of its hydrogen ions.

Answer to Problem 83A

The concentration of hydrogen ions and hydroxide ions in a neutral solution is the same.

Explanation of Solution

A pH of 7.0 indicates a neutral solution.

In a neutral solution, the concentration of hydrogen ion and hydroxide ion is equal.

The values of hydrogen ion and hydroxide ion in a neutral solution are ${\text{[H}}^{\text{+}}\text{]}=1\times {10}^{-7}\text{M}$ and ${\text{[OH}}^{-}\text{]}=1\times {10}^{-7}\text{M}$ respectively.

b.

Interpretation Introduction

Interpretation : The concentration of hydrogen ion and hydroxide ion in a basic solution is to be compared and explained.

Concept Introduction : A hydrogen ion added to a water molecule transforms it into a hydronium ion. A hydroxide ion is created when a water molecule loses one of its hydrogen ions.

Answer to Problem 83A

The concentration of hydroxide ions is greater than the concentration of hydrogen ions in a basic solution.

Explanation of Solution

pH greater than 7.0 designates a basic solution.

In a basic solution, the concentration of hydroxide ions is higher than the concentration of hydrogen ions.

The values of hydrogen ions in a basic solution are less than $1\times {10}^{-7}\text{M}$ .

c.

Interpretation Introduction

Interpretation : The concentration of hydrogen ion and hydroxide ion in an acidic solution is to be compared and explained.

Concept Introduction : A hydrogen ion added to a water molecule transforms it into a hydronium ion. A hydroxide ion is created when a water molecule loses one of its hydrogen ions.

Answer to Problem 83A

The concentration of hydrogen ions is greater than the concentration of hydroxide ions in an acidic solution.

Explanation of Solution

Acidic solutions have pH values below 7.0.

In an acidic solution, the concentration of hydrogen ions is higher than the concentration of hydroxide ions.

The values of concentration of hydrogen ion in an acidic solution are greater than $1\times {10}^{-7}\text{M}$ .