Chapter 19, Problem 36A

Interpretation Introduction

Interpretation:

The oxidation number is to be defined.

Concept introduction:

Oxidation number is the total number of electrons that an atom either gains or losses in order to form a chemical bond with another atom.

Answer to Problem 36A

Oxidation number is the total number of electrons that an atom either gains or losses in order to form an ionic bond with another atom.

Every atom involved in redox reaction has an oxidation number.

There are some rules to assign oxidation number:

• For an atom in its elemental form, oxidation number=0
• For an ion, oxidation number=charge of ion
• The sum of oxidation number value for the atoms in a molecule equal to zero for neutral compound and equal to total charge if it is a polyatomic ion
• For group (I)A, oxidation number=+1 in all compounds
• For group (II)A, oxidation number=+2 in all compounds
• For fluorine, oxidation number=-1 in all compounds

Explanation of Solution

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

Some examples for how to calculate oxidation number of atom in an element are:

The oxidation number of N in $N{H}_4{}^{+}$

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

The oxidation number of Cl in $NaCl{O}_4$

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

Conclusion