Chapter 16, Problem 34A

(a)

Interpretation Introduction

Interpretation:

The concentration of ${\text{H}}^{\text{+}}$ ion has to be calculated for a solution having $\mathrm{p}\mathrm{H}=\text{ 7}\text{.89}$.

Concept Introduction:

The acidity or alkalinity of a solution is expressed by determining $\text{pH}$ of the solution. $\text{pH}$ of a solution is defined as negative logarithm of the concentration of ${\text{H}}^{\text{+}}$ ion in the solution. $\text{pH}$ is expressed as-

  $\text{pH}\text{=}\text{-}{\text{log[H}}^{\text{+}}\text{]}$

Answer to Problem 34A

The concentration of ${\text{H}}^{\text{+}}$ ion is $1.29\times {10}^{-8}\text{M}$ .

Explanation of Solution

Using the following equation to calculate concentration of ${\text{H}}^{\text{+}}$ ion in the solution,

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

So,

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}\text{=}{\text{10}}^{\text{-pH}}\\ =10^{-7.89}=1.29\times 10^{-8}\mathrm{M}\end{array}$

The concentration of ${\text{H}}^{\text{+}}$ ion in the solution is $1.29\times {10}^{-8}\text{M}$

(b)

Interpretation Introduction

Interpretation:

The concentration of ${\text{H}}^{\text{+}}$ ion has to be calculated for a solution having $\mathrm{p}\mathrm{H}=\text{ 3}\text{.21}$.

Concept Introduction:

The acidity or alkalinity of a solution is expressed by determining $\text{pH}$ of the solution. $\text{pH}$ of a solution is defined as negative logarithm of the concentration of ${\text{H}}^{\text{+}}$ ion in the solution. $\text{pH}$ is expressed as-

  $\text{pH}\text{=}\text{-}{\text{log[H}}^{\text{+}}\text{]}$

Answer to Problem 34A

The concentration of ${\text{H}}^{\text{+}}$ ion is $6.17\times {10}^{-4}\text{M}$

Explanation of Solution

Using the following equation to calculate concentration of ${\text{H}}^{\text{+}}$ ion in the solution,

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

So,

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}\text{=}{\text{10}}^{\text{-pH}}\\ =10^{-3.21}=6.17\times 10^{-4}\mathrm{M}\end{array}$

The concentration of ${\text{H}}^{\text{+}}$ ion in the solution is $6.17\times {10}^{-4}\text{M}$ .

(c)

Interpretation Introduction

Interpretation:

The concentration of ${\text{H}}^{\text{+}}$ ion has to be calculated for a solution having $\mathrm{p}\mathrm{H}=\text{ 12}\text{.45}$.

Concept Introduction:

The acidity or alkalinity of a solution is expressed by determining $\text{pH}$ of the solution. $\text{pH}$ of a solution is defined as negative logarithm of the concentration of ${\text{H}}^{\text{+}}$ ion in the solution. $\text{pH}$ is expressed as-

  $\text{pH}\text{=}\text{-}{\text{log[H}}^{\text{+}}\text{]}$

Answer to Problem 34A

The concentration of ${\text{H}}^{\text{+}}$ ion is $3.55\times {10}^{-13}\text{M}$ .

Explanation of Solution

Using the following equation to calculate concentration of ${\text{H}}^{\text{+}}$ ion in the solution,

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

So,

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}\text{=}{\text{10}}^{\text{-pH}}\\ =10^{-12.45}=3.55\times 10^{-13}\mathrm{M}\end{array}$

The concentration of ${\text{H}}^{\text{+}}$ ion in the solution is $3.55\times {10}^{-13}\text{M}$ .

(d)

Interpretation Introduction

Interpretation:

The concentration of ${\text{H}}^{\text{+}}$ ion has to be calculated for a solution having $\mathrm{p}\mathrm{H}=\text{ 9}\text{.63}$.

Concept Introduction:

The acidity or alkalinity of a solution is expressed by determining $\text{pH}$ of the solution. $\text{pH}$ of a solution is defined as negative logarithm of the concentration of ${\text{H}}^{\text{+}}$ ion in the solution. $\text{pH}$ is expressed as-

  $\text{pH}\text{=}\text{-}{\text{log[H}}^{\text{+}}\text{]}$

Answer to Problem 34A

The concentration of ${\text{H}}^{\text{+}}$ ion is $2.34\times {10}^{-10}\text{M}$ .

Explanation of Solution

Using the following equation to calculate concentration of ${\text{H}}^{\text{+}}$ ion in the solution,

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

So,

  $\begin{array}{l}{\text{[H}}^{\text{+}}\text{]}\text{=}{\text{10}}^{\text{-pH}}\\ \text{=}{\text{10}}^{\text{-9}\text{.63}}\text{=}\text{2}\text{.34}\text{×}{\text{10}}^{\text{-10}}\text{M}\end{array}$

The concentration of ${\text{H}}^{\text{+}}$ ion in the solution is $2.34\times {10}^{-10}\text{M}$ .