Chapter 5, Problem 5.72CP

(a)

Interpretation Introduction

Interpretation: The oxidation number for the elements $Mn$ and $I$ on both sides of the given reaction equation should be determined.

Concept introduction:

In a balanced equation the number of atoms of each element as a reactant is equal to the number of atoms of that element as a product.

Change in the oxidation number of atoms involved in the reaction is one of the special characteristic of reduction reaction.

The number of electrons an atom tends to give up or gain in a chemical reaction is called oxidation number.

Oxidation: Losing electrons, increasing oxidation number.

Reduction: Gaining electron, decreasing oxidation number.

Oxidizing agent is a substance that removes electrons from another reactant in a chemical reaction and so it is reduced by taking electron onto itself and the reactant is oxidized by having its electron taken away.

Reducing agent is the element or compound in a redox reaction that donate an electron to another species and so it is oxidized.

• Rules for assigning oxidation number

1. 1. 1. The oxidation number of the atom of an uncombined element is zero.
   2. 2. The sum of the oxidation numbers of all atoms in a compound must equal to the total charge on the species.
   3. 3. Hydrogen has an oxidation number of +1 unless it is combined with metals, in which case it has an oxidation number of -1.
   4. 4. Oxygen has an oxidation number of -2, except in peroxides where it is -1 and in $O{F}_2$ where it is +2.

(b)

Interpretation Introduction

Interpretation: The oxidizing and reducing agents in the given reaction should be determined.

Concept introduction:

Change in the oxidation number of atoms involved in the reaction is one of the special characteristic of reduction reaction.

The number of electrons an atom tends to give up or gain in a chemical reaction is called oxidation number.

Oxidation: Losing electrons, increasing oxidation number.

Reduction: Gaining electron, decreasing oxidation number.

Oxidizing agent is a substance that removes electrons from another reactant in a chemical reaction and so it is reduced by taking electron onto itself and the reactant is oxidized by having its electron taken away.

Reducing agent is the element or compound in a redox reaction that donate an electron to another species and so it is oxidized.

• Rules for assigning oxidation number

1. 1. 1. The oxidation number of the atom of an uncombined element is zero.
   2. 2. The sum of the oxidation numbers of all atoms in a compound must equal to the total charge on the species.
   3. 3. Hydrogen has an oxidation number of +1 unless it is combined with metals, in which case it has an oxidation number of -1.
   4. 4. Oxygen has an oxidation number of -2, except in peroxides where it is -1 and in $O{F}_2$ where it is +2.