Chapter 19.1, Problem 6PP

Interpretation Introduction

(a)

Interpretation:

The oxidation number of N needs to be determined in $N{H}_4{}^{+}$

Concept introduction:

Oxidation number: It is defined as charge the atom would have if electrons are not shared but transfer completely.

Answer to Problem 6PP

The oxidation number of N in $N{H}_4{}^{+}$ is -3.

Explanation of Solution

The oxidation number of N is calculated as:

$\begin{array}{c}x+\left(1\times 4\right)=+1\\ x+4=+1\\ x=-3\end{array}$

Interpretation Introduction

(b)

Interpretation:

The oxidation number of As in $As{O}_4{}^{3-}$ is to be determined.

Concept introduction:

Oxidation number: It is defined as charge the atom would have if electrons are not shared but transfer completely.

Answer to Problem 6PP

The oxidation number of As in $As{O}_4{}^{3-}$ is +5.

Explanation of Solution

The oxidation number of As is calculated as:

$\begin{array}{c}x+\left(-2\times 4\right)=-3\\ x-8=-3\\ x-5=0\\ x=5\end{array}$

Interpretation Introduction

(c)

Interpretation:

The oxidation number of Cr in $Cr{O}_4{}^{2-}$ is to be determined.

Concept introduction:

Oxidation number: It is defined as charge the atom would have if electrons are not shared but transfer completely.

Answer to Problem 6PP

The oxidation number of Cr in $Cr{O}_4{}^{2-}$ is+6.

Explanation of Solution

The oxidation number of Cr is calculated as:

$\begin{array}{c}x+\left(-2\times 4\right)=-2\\ x-8=-2\\ x-6=0\\ x=6\end{array}$