1. CHAPTER 25
Acids, Bases and Salts

2. Section 1-Acids and Bases
Acid—a substance that produces hydrogen ions in a water solution (H donor)
It is the ability to produce these ions that gives acid their characteristic properties
Properties: sour taste, corrosive, react strongly w/certain metals, turns litmus red

3. Common Acids Citric acid—found in citrus fruits
Lactic acid—found in yogurt and buttermilk
Acetic acid—vinegar (pickles
Hydrochloric acid—in your stomach
Others used in industry: sulfuric, phosphoric, nitric and hydrochloric

4. Bases
Base—any substance that forms hydroxide ions, OH, in a water solution OR any substance that accepts H from acids (H acceptor)
Properties: many are crystalline solids, feel slippery, taste bitter, can be corrosive, turns litmus blue

5. Common examples of Bases:
Ex: egg whites, baking powder, milk of magnesia, antacids, ammonia, etc.
Chart-pg. 769

6. Solutions of Acids and Bases
Compounds that can form hydroxide ions in solution are bases
These substances release OH ions in water. **If a solution contains MORE OH ions than H3O ions, it is referred to as BASIC
Ammonia in solution—pg. 771 (harmful effects of ammonia w/other cleaners)

7. Solutions of both acids and bases produce some ions that are capable of carrying electric current to some extent-
**These solutions are said to be CONDUCTORS

8. Section 2—Strength of Acids & Bases
The strength of an acid or base depends on how completely a compound separates into ions when dissolved in water
Strong acid—an acid that ionizes almost completely in solution
Ex: HCl, HNO3 and H2SO4
Weak acid—an acid that only partly ionizes
Ex: acetic and carbonic acids

9. Bases: Strong base—dissociates completely in solution
Ex: sodium hydroxide
Weak base—one that does not ionize completely
ex: Ammonia
Remember: Strong and Weak acids and bases are not to be confused with DILUTION and CONCENTRATION of acids and bases

10. pH of a Solution
pH—a measure of the concentration of H ions in a solution
The greater the H concentration is, the lower the pH is and the more acidic the solution
pH—measures how acidic or bassic a solution is

11. pH Scale pH scale—ranges from 0 to 14 0-most acidic 14-most basic
7-neutral
Universal indicator paper—can be sued to determine pH of substances (colors are matched to determine pH level)

12. pH meter-can be used to determine the pH of a solution more precisely
Operated by immersing electrodes in the solution and reading a dial
Blood pH—pH of blood must remain between 7.0 and 7.8
Buffers—help keep your blood close to a nearly constant pH of 7.4 (neutralizers)

13. Section 3: Salts
Neutralization: a chemical reaction between an acid and a base that takes place in a water solution
Salt: a compound formed when the negative ions from an acid combine w/the positive ions from a base
Acid + Base- Salt + Water

14. Salts Are essential for many animals large and small
Most are composed of a positive metal ion and an ion with a negative charge
Salts also form when acids react with metals (a single displacement reaction)
Visualizing Salt—pg. 779

15. Titration
Titration: a process in which a solution of known concentration is used to determine the concentration of another solution
Ex: using phenolphthalein to determine concentration of acid/base solution—pg 780
Natural indicators: red cabbage, radishes, roses, hydrangeas, grape juice, etc.

16. Soaps and Detergents
Soap: organic salts with a nonpolar organic chain of carbon atoms on one end, and either a sodium or potassium salt of a carboxylic acid at the other end
Ex: pg. 782

17. Detergents
Like soaps, detergents have long hydrocarbon chains, but instead of a carboxylic acid group, have a either a sulfonic acid or phosphoric acid group
These acids form more soluble salts in hard water and lessen the soap scum problem
Problems: pg. 783

18. Esters: Can be thought of as the organic counterparts of salts
Are made from acids, and water is formed in the reaction used to prepare them
However, salts are made from bases and ESTERS are made from alcohols that are not bases but have a hydroxyl group
Uses: perfumes, soaps, fibers, flavoring in drinks, etc.