Acids and bases are common substances found in many every day items, from fruit juices and soft drinks to soap. In this chapter, we will examine the properties of acids and bases, and learn about the chemical nature of these important compounds. We will cover pH, and how to calculate the pH of a solution. 13.1: Definitions and Properties of Acids/Bases 13.1.1: Acids and Bases Definitions 13.1.2: Reactions of Acids and Bases 13.1.3: Acid and Base Strength 13.1.4: Acid Dissociation Constants 13.2: Measuring Acidity 13.2.1: Water as Both an Acid and a Base 13.2.2: Measuring Acidity in Aqueous Solutions- The pH Scale 13.2.3: Working with pH 13.3: Maintaining pH Using Buffer Solutions A buffer is a solution that resists sudden changes in pH. 13.3.1: Biological Buffers