Chapter 18, Problem 2A

Interpretation Introduction

Interpretation: Reduction process needs to be defined.

Concept introduction: The change in oxidation state explains the gain and loss of electrons in the oxidation−reduction reactions. One half-reaction performs a reduction process and other half-reaction represents an oxidation process.

Answer to Problem 2A

Reduction is gain of electrons. Equation that shows reduction of chlorine is as follows:

${\text{Cl}}_{\text{2}}\left(g\right){\text{+2e}}^{-}\to 2{\text{Cl}}^{-}$

Explanation of Solution

Gain of electrons by ion, molecules or atoms is termed as reduction. Reduction is decrease in oxidation state for an element. Due to gain of one or more electrons by element, the oxidation state decreases. Equation that shows reduction of chlorine is as follows:

${\text{Cl}}_{\text{2}}\left(g\right){\text{+2e}}^{-}\to 2{\text{Cl}}^{-}$

Conclusion

A chemical reaction includes transfer of electrons. In reduction, gain of electrons decreases the oxidation state.