One important type of chemical reaction is the oxidation-reduction reaction, also known as the redox reaction. Although we introduced redox reactions in Section 4.7, it is worth reviewing some basic concepts.
- 12.1 Oxidation-Reduction Reactions
- Oxidation-reduction (redox) reactions involve the transfer of electrons from one atom to another. Oxidation numbers are used to keep track of electrons in atoms. There are rules for assigning oxidation numbers to atoms. Oxidation is an increase in oxidation number (loss of electrons); reduction is a decrease in oxidation number (gain of electrons).
- 12.2 Balancing Redox Reactions
- Redox reactions can be balanced by inspection or by the half reaction method. A solvent may participate in redox reactions; in aqueous solutions, H2O, H+, and OH− may be reactants or products.
Thumbnail: Copper from a wire is displaced by silver in a silver nitrate solution it is dipped into, and solid silver precipitates out. Image used with permission (CC SA-BY 3.0 au; Toby Hudson).