Chapter 24, Problem 24.54P

(a)

Interpretation Introduction

Interpretation:

The oxidation state of nitrogen atoms in $N{H}_3$ has to be assigned.

Concept introduction:

Rules for assigning oxidation state are given below.

1. 1. Free elements have an oxidation state of $0.$
2. 2. The sum of the oxidation states of all the atoms in a species and net charge on the species must be equal.
3. 3. The alkali metal atoms $\left(Li,Na,K,Rb,andCs\right)$ in compounds have an oxidation state of $+1$.
4. 4. Fluorine atoms have an oxidation state of $-1$.
5. 5. The alkaline-earth atoms $\left(Be,Mg,Ca,Sr,Ba,andRa\right)andZnandCd$ in compounds are always assigned an oxidation state of $+2$.
6. 6. Hydrogen atoms have an oxidation state of $+1$
7. 7. Oxygen atom have and oxidation state of $-2.$
8. 8. The above seven rules is used to find out the oxidation states in many of the cases. But in some cases these rules are not sufficient.  In such cases Lewis formulas can be used to determine oxidation states.  The oxidation states can be assigned by the following steps:
   1. a. Lewis formula for the molecule or ion should be written.
   2. b. The bonded electron should be assigned to the atom which has more electronegativity than the other and if the electronegativity is same then electron has to be divided among them.
9. c. The total number of valence electrons assigned to each atom in the previous step has to be added.
10. d. The oxidation state of each main-group element in the molecule can be determined by using the following formula.

Oxidation state $=$ (number of valance electrons in the free (non-bonded) atom) $-$ (number of valence electrons assigned to the atom in the molecule)

(b)

Interpretation Introduction

Interpretation:

The oxidation state of nitrogen atoms in $N_2$ has to be assigned.

Concept introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

The oxidation state of nitrogen atoms in $N_2{H}_4$ has to be assigned.

Concept introduction:

Refer to part (a).

(d)

Interpretation Introduction

Interpretation:

The oxidation state of nitrogen atoms in $N_{2}O$ has to be assigned.

Concept introduction:

Refer to part (a).

(e)

Interpretation Introduction

Interpretation:

The oxidation state of nitrogen atoms in $NO$ has to be assigned.

Concept introduction:

Refer to part (a).