Chapter 17, Problem 95QRT

(a)

Interpretation Introduction

Interpretation:

The reason for the fact that ${\text{Co}}^{3+}$ is not stable in aqueous solution has to be stated.

Concept Introduction:

A reducing agent is a reacting species in the reaction that reduces another reacting species.  A reducing agent itself gets oxidized when reacts with another species.  The reducing agent donates electrons.  An oxidizing agent is a reacting species in the reaction that oxidize another reacting species.  An oxidizing agent itself gets reduced when it reacts with another species.  The oxidizing agent accepts electrons.

(b)

Interpretation Introduction

Interpretation:

The reason for the fact that ${\text{Fe}}^{2+}$ is not stable in air has to be stated.

Concept Introduction:

Refer to part (a).