Chapter U4.19, Problem 6E

(a)

Interpretation Introduction

Interpretation:

The [H⁺] concentration of a solution with pH = 9 needs to be calculated.

Concept Introduction:

The acidity of a solution is expressed in terms of its pH which is essentially the measure of the hydrogen ion (H⁺) concentration of that solution. Mathematically,

  $\begin{array}{l}\text{pH = }-{\text{log[H}}^{\text{+}}\text{] }\\ \text{i}\text{.e}{\text{. [H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\text{ -----(1)}\end{array}$

If the pH is below 7 the solution is termed as acidic, if greater than 7 the solution is basic. A neutral solution will have a pH = 7.

Answer to Problem 6E

  ${\text{[H}}^{\text{+}}\text{] = 1}\text{.0}\times {\text{10}}^{-9}\text{ M}$

Explanation of Solution

The pH of the solution is given as follows:

pH = 9

The hydrogen ion concentration can be calculated as follows:

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\\ ={10}^{-\text{9}}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The [H⁺] concentration of a solution with pH = 7.3 needs to be calculated.

Concept Introduction:

The acidity of a solution is expressed in terms of its pH which is essentially the measure of the hydrogen ion (H⁺) concentration of that solution. Mathematically,

  $\begin{array}{l}\text{pH = }-{\text{log[H}}^{\text{+}}\text{] }\\ \text{i}\text{.e}{\text{. [H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\text{ -----(1)}\end{array}$

If the pH is below 7 the solution is termed as acidic, if greater than 7 the solution is basic. A neutral solution will have a pH = 7.

Answer to Problem 6E

  ${\text{[H}}^{\text{+}}\text{] = }5.0\times {10}^{-8}\text{ M}$

Explanation of Solution

The pH of the solution is as follows:

pH = 7.3

The hydrogen ion concentration can be calculated as follows:

Based on equation (1):

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\\ ={10}^{-7.3}=5.0\times {10}^{-8}\text{ M}\end{array}$

(c)

Interpretation Introduction

Interpretation:

The [H⁺] concentration of a solution with pH = 2.9 needs to be calculated.

Concept Introduction:

The acidity of a solution is expressed in terms of its pH which is essentially the measure of the hydrogen ion (H⁺) concentration of that solution. Mathematically,

  $\begin{array}{l}\text{pH = }-{\text{log[H}}^{\text{+}}\text{] }\\ \text{i}\text{.e}{\text{. [H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\text{ -----(1)}\end{array}$

If the pH is below 7 the solution is termed as acidic, if greater than 7 the solution is basic. A neutral solution will have a pH = 7.

Answer to Problem 6E

  ${\text{[H}}^{\text{+}}\text{] = }1.25\times {10}^{-3}\text{ M}$

Explanation of Solution

The pH of the solution is given as follows:

pH = 2.9

The hydrogen ion concentration can be calculated as follows:

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\\ ={10}^{-2.\text{9}}=1.25\times {10}^{-3}\text{ M}\end{array}$

(d)

Interpretation Introduction

Interpretation:

The [H⁺] concentration of a solution with pH = 10.2 needs to be calculated.

Concept Introduction:

The acidity of a solution is expressed in terms of its pH which is essentially the measure of the hydrogen ion (H⁺) concentration of that solution. Mathematically,

  $\begin{array}{l}\text{pH = }-{\text{log[H}}^{\text{+}}\text{] }\\ \text{i}\text{.e}{\text{. [H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\text{ -----(1)}\end{array}$

If the pH is below 7 the solution is termed as acidic, if greater than 7 the solution is basic. A neutral solution will have a pH = 7.

Answer to Problem 6E

  ${\text{[H}}^{\text{+}}\text{] = }6.31\times {10}^{-11}\text{ M}$

Explanation of Solution

The pH of the solution is given as follows:

pH = 10.2

The hydrogen ion concentration can be calculated as follows:

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}={10}^{-\text{pH}}\\ ={10}^{-10.2}=6.31\times {10}^{-11}\text{ M}\end{array}$