22.1. The Nature of Oxidation and Reduction http://www.ck12.org
FIGURE 22.4
Small blocks of zinc are attached to the steel hull of this ship. The zinc
corrodes more easily than the iron, so the iron is protected.Lesson Summary
- Historically, oxidation was defined as a gain of oxygen, while reduction was described a loss of oxygen.
- The modern definitions of oxidation and reduction have been broadened to include any loss or gain of elec-
trons. This can refer to either a full loss or gain of electrons, as in an ionic reaction, or a partial loss or gain of
electrons, as you might see in a molecular reaction. - An oxidizing agent is reduced in a redox reaction, while a reducing agent is oxidized.
- Oxidation and reduction must occur simultaneously in redox reactions.
- Corrosion refers to the deterioration of metals by a variety of oxidative processes. Prevention of corrosion can
be accomplished by protecting the surface or by connecting the metal to something else that is oxidized more
readily.
Lesson Review Questions
Reviewing Concepts
- Explain why oxidation and reduction always occur together in a reaction.
- What happens to the oxidizing agent in a redox reaction? What happens to the reducing agent?
- Use the original definitions of oxidation and reduction to determine whether nitrogen monoxide (NO) is being
oxidized or reduced in each equation below.
a. 2NO(g)→N 2 (g) + O 2 (g)
b. 2NO(g) + O 2 (g)→NO 2 (g) - Identify each half-reaction below as an oxidation or a reduction.
a. Rb→Rb++ e−
b. Te + 2e−→Te^2 −
c. 2H++ 2e−→H 2
d. P^3 −→P + 3e− - Based on whether they would prefer to lose or gain electrons, determine whether the following substances are
more likely to be oxidizing agents or reducing agents.
a. K