Chapter 16, Problem 51QAP

. Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pOH values.

a. pOH = 14.95

b. pOH = 7.00

c. pOH = 12.94

d. pOH = 1.02

Interpretation Introduction

(a)

Interpretation:

The hydrogen ion concentration should be calculated.

Concept Introduction:

The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more than the solution is more acetic, if it is low, solution is less acidic.

The pH of solution is defined as negative log of hydrogen ion concentration thus, it can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Here, $\left[{\text{H}}^{+}\right]$ is concentration of hydrogen ion.

Similarly, pOH of a solution is defined as negative log of hydroxide ion concentration thus, it can be calculated as follows:

$\text{p}\text{O}\text{H}=-\text{log}\left[{\text{OH}}^{-}\right]$

Here, $\left[{\text{OH}}^{-}\right]$ is concentration of hydroxide ion.

pH and pOH of a solution are related to each other as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

In a pH scale, if the value of pH is below 7 the solution is said to be acidic in nature, if the Ph value is above 7 it is said to be basic in nature. At pH 7, the solution is neutral.

Answer to Problem 51QAP

$8.91\times {10}^{-10}\text{ mol/L}$.

Explanation of Solution

Given Information:

The pOH of solution is 4.95

Calculation:

From the pOH of solution, pH can be calculated as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

On rearranging,

$\text{p}\text{H}=14-\text{p}\text{O}\text{H}$

Putting the values,

$\begin{array}{c}\text{p}\text{H}=14-4.95\\ =9.05\end{array}$

Now, from pH, hydrogen ion concentration can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Rearranging,

$\left[{\text{H}}^{+}\right]={10}^{-\text{p}\text{H}}$

Putting the value,

$\begin{array}{c}\left[{\text{H}}^{+}\right]={10}^{-9.05}\\ =8.91\times {10}^{-10}\text{ mol/L}\end{array}$

Thus, hydrogen ion concentration is $8.91\times {10}^{-10}\text{ mol/L}$.

Interpretation Introduction

(b)

Interpretation:

The hydrogen ion concentration should be calculated.

Concept Introduction:

The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more than the solution is more acetic, if it is low, solution is less acidic.

The pH of solution is defined as negative log of hydrogen ion concentration thus, it can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Here, $\left[{\text{H}}^{+}\right]$ is concentration of hydrogen ion.

Similarly, pOH of a solution is defined as negative log of hydroxide ion concentration thus, it can be calculated as follows:

$\text{p}\text{O}\text{H}=-\text{log}\left[{\text{OH}}^{-}\right]$

Here, $\left[{\text{OH}}^{-}\right]$ is concentration of hydroxide ion.

pH and pOH of a solution are related to each other as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

In a pH scale, if the value of pH is below 7 the solution is said to be acidic in nature, if the Ph value is above 7 it is said to be basic in nature. At pH 7, the solution is neutral.

Answer to Problem 51QAP

${10}^{-7}\text{mol/L}$.

Explanation of Solution

Given Information:

The pOH of solution is 7.00

Calculation:

From the pOH of solution, pH can be calculated as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

On rearranging,

$\text{p}\text{H}=14-\text{p}\text{O}\text{H}$

Putting the values,

$\begin{array}{c}\text{p}\text{H}=14-7.00\\ =7.00\end{array}$

Now, from pH, hydrogen ion concentration can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Rearranging,

$\left[{\text{H}}^{+}\right]={10}^{-\text{p}\text{H}}$

Putting the value,

$\left[{\text{H}}^{+}\right]={10}^{-7}\text{mol/L}$

Thus, hydrogen ion concentration is ${10}^{-7}\text{mol/L}$.

Interpretation Introduction

(c)

Interpretation:

The hydrogen ion concentration should be calculated.

Concept Introduction:

The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more than the solution is more acetic, if it is low, solution is less acidic.

The pH of solution is defined as negative log of hydrogen ion concentration thus, it can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Here, $\left[{\text{H}}^{+}\right]$ is concentration of hydrogen ion.

Similarly, pOH of a solution is defined as negative log of hydroxide ion concentration thus, it can be calculated as follows:

$\text{p}\text{O}\text{H}=-\text{log}\left[{\text{OH}}^{-}\right]$

Here, $\left[{\text{OH}}^{-}\right]$ is concentration of hydroxide ion.

pH and pOH of a solution are related to each other as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

In a pH scale, if the value of pH is below 7 the solution is said to be acidic in nature, if the Ph value is above 7 it is said to be basic in nature. At pH 7, the solution is neutral.

Answer to Problem 51QAP

$0.087\text{ mol/L}$.

Explanation of Solution

Given Information:

The pOH of solution is 12.94

Calculation:

From the pOH of solution, pH can be calculated as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

On rearranging,

$\text{p}\text{H}=14-\text{p}\text{O}\text{H}$

Putting the values,

$\begin{array}{c}\text{p}\text{H}=14-12.94\\ =1.06\end{array}$

Now, from pH, hydrogen ion concentration can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Rearranging,

$\left[{\text{H}}^{+}\right]={10}^{-\text{p}\text{H}}$

Putting the value,

$\begin{array}{c}\left[{\text{H}}^{+}\right]={10}^{-1.06}\\ =0.087\text{ mol/L}\end{array}$

Thus, hydrogen ion concentration is $0.087\text{ mol/L}$.

Interpretation Introduction

(d)

Interpretation:

The hydrogen ion concentration should be calculated.

Concept Introduction:

The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more than the solution is more acetic, if it is low, solution is less acidic.

The pH of solution is defined as negative log of hydrogen ion concentration thus, it can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Here, $\left[{\text{H}}^{+}\right]$ is concentration of hydrogen ion.

Similarly, pOH of a solution is defined as negative log of hydroxide ion concentration thus, it can be calculated as follows:

$\text{p}\text{O}\text{H}=-\text{log}\left[{\text{OH}}^{-}\right]$

Here, $\left[{\text{OH}}^{-}\right]$ is concentration of hydroxide ion.

pH and pOH of a solution are related to each other as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

In a pH scale, if the value of pH is below 7 the solution is said to be acidic in nature, if the Ph value is above 7 it is said to be basic in nature. At pH 7, the solution is neutral.

Answer to Problem 51QAP

$1.047\times {10}^{-13}\text{ mol/L}$.

Explanation of Solution

Given Information:

The pOH of solution is 1.02

Calculation:

From the pOH of solution, pH can be calculated as follows:

$\text{p}\text{H}+\text{p}\text{O}\text{H}=14$

On rearranging,

$\text{p}\text{H}=14-\text{p}\text{O}\text{H}$

Putting the values,

$\begin{array}{c}\text{p}\text{H}=14-1.02\\ =12.98\end{array}$

Now, from pH, hydrogen ion concentration can be calculated as follows:

$\text{p}\text{H}=-\text{log}\left[{\text{H}}^{+}\right]$

Rearranging,

$\left[{\text{H}}^{+}\right]={10}^{-\text{p}\text{H}}$

Putting the value,

$\begin{array}{c}\left[{\text{H}}^{+}\right]={10}^{-12.98}\\ =1.047\times {10}^{-13}\text{ mol/L}\end{array}$

Thus, hydrogen ion concentration is $1.047\times {10}^{-13}\text{ mol/L}$.