2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases Section 6.1 Summary – pages 141-151 The pH is a measure of how acidic or basic a solution is. A scale with values ranging from below 0 to above 14 is used to measure pH. More acidic NeutralMore basic

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases, continued Acids –Substances with a pH below 7 are acidic. Acids are substances that form hydrogen ions (H + ) in water. –A solution is neutral if its pH equals zero. –Acids are very corrosive (they eat away at other materials they come in contact with). –Acids play a large role in chemical digestion, especially in the stomach, where gastric juices lower the stomach’s pH to 2.

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases, continued Bases Substances with a pH above 7 are basic. A base is any substance that forms hydroxide ions (OH - ) in water. pH 11

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2 Click below to watch the Visual Concept. Visual Concept Bases Section 3 Water and Solutions

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases, continued pH

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2 The pH Scale Section 3 Water and Solutions

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Water and Solutions Chapter 2 Acids and Bases, continued Buffers –Buffers are chemicals that neutralize the effects of adding small amounts of either an acid or a base to a solution.

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 2 Click below to watch the Visual Concept. Visual Concept pH Section 3 Water and Solutions