Chapter 4, Problem 4.78P

(a)

Interpretation Introduction

Interpretation:

The oxidation number of sulfur in ${\text{H}}_{\text{2}}\text{S}$ is to be calculated.

Concept introduction:

Oxidation of a species involves the loss of electrons by that species and reduction of a species involves the gain of electrons by that species.

Oxidation number is defined as the formal charge an atom would gain if all the bonds attached to it in a compound are heterolytically cleaved. Oxidation number can be a positive or negative number but cannot be fractional.

(b)

Interpretation Introduction

Interpretation:

The oxidation number of sulfur in ${\text{SO}}_3^{2-}$ is to be calculated.

Concept introduction:

Oxidation of a species involves the loss of electrons by that species and reduction of a species involves the gain of electrons by that species.

Oxidation number is defined as the formal charge an atom would gain if all the bonds attached to it in a compound are heterolytically cleaved. Oxidation number can be a positive or negative number but cannot be fractional.