Chapter 8

Acids, Bases, and Acid-Base Reactions

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8.1 Strong and Weak Acids and Bases

8.2 pH and Acidic and Basic Solutions

8.3 Arrhenius Acid-Base Reactions

8.4 Brønsted-Lowry Acids and Bases

Review Skills

The presentation of information in this chapter assumes that you can already perform the tasks listed below. You can test your readiness to proceed by answering the Review Questions at the end of the chapter. This might also be a good time to read the Chapter Objectives, which precede the Review Questions.

Given a chemical name or formula, decide whether or not it represents an ionic compound. (Section 5.3)

Describe what occurs when a strong, monoprotic acid, such as HCl, is added to water. (Section 6.3)

Describe what occurs when a weak, monoprotic acid, such as acetic acid, is added to water. (Section 6.3)

Describe the structure of liquid water. (Section 7.2)

Write a description of the changes that take place when an ionic compound is dissolved in water. (Section 7.2)

Predict ionic solubility. (Section 7.3)

Predict the products of double-displacement reactions. (Section 7.3)

t’s test day in chemistry class—they’ve been learning about acids and bases—and Fran unwisely skips breakfast in order to have time for some last-minute studying. As she reads, she chews on a candy bar and sips a cup of coffee. Fran is well aware that the sugary candy sticking to her molars is providing breakfast for the bacteria in her mouth, which in turn produce an acid that will dissolve some of the enamel on her teeth. Feeling a little guilty about all that sugar from the candy, Fran drinks her coffee black, even though she doesn’t like the taste. The caffeine in her coffee is a base, and like all bases, it tastes bitter.

Fran’s junk-food breakfast and her worrying about the exam combine to give her an annoying case of acid indigestion, which she calms by drinking some baking soda mixed with water. The baking soda contains a base that “neutralizes” some of her excess stomach acid.

After taking the exam, Fran feels happy and confident. All those hours working problems, reviewing the learning objectives, and participating in class really paid off. Now she’s ready for some lunch. Before eating, she washes her hands with soap made from the reaction of a strong base and animal fat. One of the reasons the soap is slippery is because all bases feel slippery on the skin. To compensate for her less-than-healthy breakfast, Fran chooses salad with a piece of lean meat on top for lunch. Like all acids, the vinegar in her salad dressing tastes sour. Her stomach produces just enough additional acid to start the digestion of the protein from the meat.

Read on to learn more about the acids and bases that are important in Fran’s life and your own: what they are and how they react with each other.

The vinegar in salad dressing tastes sour, as do all acids.