Chapter 19, Problem 45A

Interpretation Introduction

(a)

Interpretation:

The oxidation number of $Cr$ in $CaCr{O}_4$ 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 45A

The oxidation number of $Cr$ in $CaCr{O}_4$ is+6.

Explanation of Solution

The oxidation number of $Cr$ is calculated as:

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

Interpretation Introduction

(b)

Interpretation:

The oxidation number of $S$ in $NaHS{O}_4$ 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 45A

The oxidation number of $S$ in $NaHS{O}_4$ is+3.

Explanation of Solution

The oxidation number of $S$ is calculated as:

$\begin{array}{c}+1+1+x+\left(-2\times 4\right)=0\\ 2+x-8=0\\ x-6=0\\ x=6\end{array}$

Interpretation Introduction

(c)

Interpretation:

The oxidation number of $N$ in $N{O}_2{}^{-}$ 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 45A

The oxidation number of $N$ in $N{O}_2{}^{-}$ is +3.

Explanation of Solution

The oxidation number of N is calculated as:

$\begin{array}{c}x+\left(-2\times 2\right)=-1\\ x-4=-1\\ x-3=0\\ x=3\end{array}$

The oxidation number of $N$ in $N{O}_2{}^{-}$ is +3.

Interpretation Introduction

(d)

Interpretation:

The oxidation number of $Br$ in $Br{O}_3{}^{-}$ 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 45A

The oxidation number of $Br$ in $Br{O}_3{}^{-}$ is 6.

Explanation of Solution

The oxidation number of $Br$ is calculated as:

$\begin{array}{c}x+\left(-2\times 3\right)=-1\\ x-6=-1\\ x-5=0\\ x=5\end{array}$

The oxidation number of $Br$ in $Br{O}_3{}^{-}$ is 6.