Chapter 19, Problem 58A

Interpretation Introduction

Interpretation:

The effect on number of electrons in each half reaction of a redox process is to be described.

Concept introduction:

Oxidation half-reaction: The half part of redox reaction which represent oxidation.

Reduction half-reaction: The half part of redox reaction which represent reduction.

Answer to Problem 58A

In oxidation half-reaction, electrons are lost equal to change in oxidation number of the species.

Reduction half-reaction, electrons are gained equal to change in oxidation number of the species.

Explanation of Solution

Let’s take example:

$Zn+C{u}^{+2}\to Z{n}^{+2}+Cu$

Oxidation half reaction is:

$Zn\to Z{n}^{+2}+2e^{-}$

This reaction shows the number of electrons lost.

Reduction half reaction is:

$C{u}^{+2}+2e^{-}\to Cu$

This half reaction shows the electrons gained in reduction.

Conclusion

Thus half cell reactions represent oxidation and reduction separately and the number of electrons gained or lost during the process.