Chapter 5, Problem 5.81E

Interpretation Introduction

Interpretation:

The option corresponding to the correct oxidation number of sulfur in the compound sodium thiosulfate, ${\text{Na}}_{\text{2}}{\text{S}}_{\text{2}}{\text{O}}_{\text{3}}$ is to be identified.

Concept Introduction:

The oxidation state or number in a compound is the charge present on the individual atom if all the bonds are assumed to be ionic. The oxidation number is assigned by the following set of rules:

1. The oxidation number present on a neutral compound is always zero.

2. The oxidation number of atoms present in an element in the pure form is zero.

3. In the compounds, if halogens are present the oxidation number of halogens is $-1$, but when oxygen is present with them they have different oxidation number.

4. The oxidation numbers of Group $1$ metals are always $+1$ and Group $2$ metals are always $+2$.

5. The common oxidation number of oxygen in most compounds is $-2$ and oxidation number of hydrogen is $+1$.