Chapt. 7: Acids & Bases

1. The Nature of Acids & Bases

1.1. Definitions

1.1.1. Arrhenius

1.1.2. Brønstead & Lowry

1.1.3. Lewis

1.2. Dissolution of an acid in water

1.3. Ka

2. Strategy for Solving Acid-Base Problems

2.1. List major species

2.2. Look for rxns that go to completion, determine [products]

2.3. Define each major species as an acid or base

2.4. Pick equilibrium that controls pH

3. Bases

3.1. Strong bases dissociate completely in water

3.2. Hydroxides of the Group 1A & 2A elements all strong bases

3.3. Some bases accept protons but do not contain hydroxide

3.4. Kb

4. Acid Strength

4.1. Strong & weak Acids

4.2. Diprotic acids

4.3. Halo-acids

4.4. Water as an acid & base

5. Polyprotic Acids

5.1. More than one H+ dissociating in steps

5.2. Examples

5.2.1. Carbonic Acid

5.2.2. Phosphoric Acid

5.2.3. Sulfuric acid

6. Strong Acid Solutions in Which Water Contributes to the H+ Concentration

6.1. Applies when [HA]~10^-7 M

6.2. Charge balance equation

6.3. Same procedure works for strong base solutions

7. The pH Scale

7.1. pH definition

7.2. Other log scales

8. Acid Solutions in Which Water Contributes to the H+ Concentration

8.1. Dilute solution of a very weak acid

8.2. Determine [H+], [OH-], [HA] and [A-]

8.3. Re-derive Ka in terms of [H+] & [HA]0

9. Calculating the pH of Strong Acid Solutions

9.1. Identify major species

9.2. Focus on chemistry of solution components

9.3. Consider sources of H+ from all major species

10. Acid-Base Properties of Salts

10.1. Salt: an ionic compound that breaks into its ionic components when dissolved in water

10.2. Salt solutions

10.2.1. Neutral

10.2.2. Basic

10.2.3. Acidic

10.2.4. Both acidic & basic

10.3. Base strength in aqueous solution

11. Calculating the pH of Weak Acid Solutions

11.1. A weak acid dissolved in water is a model for any equilibrium in solution

11.2. pH of a mixture of two weak acids of very different strengths

11.3. Percent dissociation

12. Definitions of acid & base predict chemistry

13. Conjugate base: everything in the acid except the H+ Conjugate acid: everything in the base plus a H+

14. Stronger the acid, weaker the conjugate base Stronger the base, weaker the conjugate acid

15. Autoionization of water gives very important Kw=10^-14

16. Solve A/B problems strategically

16.1. Key Strategy: IDENTIFY MAJOR SPECIES

16.2. Remember autoionization of H2O, determine if it is important

17. Strong bases dissociate to produce [OH-] ≈ [Base] Weak bases react with water

18. PP acids dissociate in successive steps, each with a weaker Ka than the previous step

19. To determine the pH of a salt solution, answer the question: What are the acid-base properties & strength of each component?

20. For an aqueous solution of an acid/base pair, you can calculate Kb from Ka & Kw or vice versa

21. To solve problems where H2O contributes H+, use Ka, Kw, material and charge balance