Unit 7: Acid-Base and Oxidation-Reduction Reactions
In this unit, we study two important types of chemical reactions: acid-base and oxidation-reduction. We will discuss how these types of reactions occur in all aspects of science and in everyday life. We will also review the properties of acids and bases and introduce two acid-base definitions: Arrhenius and Brønsted-Lowry.
We will perform pH calculations and learn how to use the pH scale to identify acidic and alkaline solutions. Then, we will discuss oxidation and reduction, also known as electron transfer reactions. We will also learn how to write and balance equations for oxidation-reduction reactions and introduce some common oxidizing and reducing agents.
Completing this unit should take you approximately 4 hours.
7.1: Acids and Bases
Before we begin examining acid-base chemistry, we need to define acids and bases. As stated above, there are multiple definitions of acids and bases. First, let's take a look at the Arrhenius definition. The Arrhenius definition states that an acid is a substance that produces hydrogen ions (H+ ions) in an aqueous (water) solution. A base is a substance that produces hydroxide ions (OH- ions) in an aqueous solution. The reaction where an acid loses a hydrogen to produce H+ (or a base loses an OH to produce OH-) is called a dissociation reaction.
7.2: Oxidation-Reduction Reactions
Now let's explore oxidation-reduction reactions. These reactions are tremendously important in our every-day lives. For example, they are the basis of batteries, explain why rusting occurs, and are common reactions in our human metabolism. Oxidation-reduction reactions involve the transfer of electron(s) from one reactant to the other.