Chapter 19.1, Problem 7PP

Interpretation Introduction

(a)

Interpretation:

The oxidation number of N in $N{H}_3$ 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 7PP

The oxidation number of N in $N{H}_3$ is-3.

Explanation of Solution

The oxidation number of N is calculated as:

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

Interpretation Introduction

(b)

Interpretation:

The oxidation number of N in $KCN$ 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 7PP

The oxidation number of N in KCN is +3

Explanation of Solution

Since, potassium has +1 oxidation number so CN should have oxidation state of -1

Further nitrogen belongs to 15^th group, so it should have oxidation number of +3

Interpretation Introduction

(c)

Interpretation:

The oxidation number of N in $N_2{H}_4$ 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 7PP

The oxidation number of N in $N_2{H}_4$ is -2.

Explanation of Solution

The oxidation number of N is calculated as:

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