1. The Chemistry of Acids and Bases

2. Acids and Bases: Definitions At the conclusion of our time together, you should be able to: 1. Define an acid in 3 different ways, Arrhenius, Bronsted-Lowry, Lewis 2. Define a base in 3 different ways, Arrhenius, Bronsted-Lowry, Lewis 3. Identify conjugate acids and bases

3. Acid/Base Definitions Definition #1: Arrhenius (traditional) Acids – formula starts with H produce H + ions (or hydronium ions H 3 O + ) HF + H 2 O  F - + H 3 O + HF  F - + H + Bases – formula ends with OH produce OH - ions LiOH  Li + + OH - Salt – Compound without H first or OH last Monoprotic = 1 H + /OH - Diprotic = 2 H + / OH - Triprotic = 3 H + /OH -

4. Acid

5. Base

6. Acid/Base Definitions Definition #2: Brønsted – Lowry Acids – proton donor Bases – proton acceptor A “proton” is really just a hydrogen atom that has lost it’s electron!

7. A Brønsted-Lowry acid is a proton donor A Brønsted-Lowry base is a proton acceptor acidbase

8. Conjugate Pairs Conjugate Acid – formed when base accepts H + Conjugate Base – part of acid left after H + is donated Found on the product side

9. Learning Check! Label the acid, base, conjugate acid, and conjugate base in each reaction: NH 2 - + CH 3 OH ↔ CH 3 O - + NH 3 HCN + SO 4 2- ↔ HSO 4 - + CN -

10. Acids & Base Definitions Lewis acid - a substance that accepts an electron pair Lewis base - a substance that donates an electron pair Definition #3 – Lewis

11. Lewis Examples BH 3 PBr 3 SeI 4 SF 6

12. Lewis Acids & Bases Formation of hydronium ion is an excellent example of the Lewis definition. Electron pair of the new O-H bond originates on the Lewis base.Electron pair of the new O-H bond originates on the Lewis base.

13. Acids and Bases: Definitions Let’s see if you can: 1. Define an acid in 3 different ways, Arrhenius, Bronsted-Lowry, Lewis 2. Define a base in 3 different ways, Arrhenius, Bronsted-Lowry, Lewis 3. Identify conjugate acids and bases

14. Get Your Clicker!!!

15. Which of the following definitions of an acid includes conjugate acids? 1.Arrhenius 2.Bronsted-Lowry 3.Lewis 4.Kenzig 5.Woods 6.Toburen 7.Sabol 8.Sanson

16. Which of the following definitions of an acid defines an acid as a proton donor? 1.Arrhenius 2.Bronsted-Lowry 3.Lewis 4.Kenzig 5.Woods 6.Toburen 7.Sabol 8.Sanson

17. Which of the following definitions of an acid defines an acid as accepting an electron pair? 1.Arrhenius 2.Bronsted-Lowry 3.Lewis 4.Kenzig 5.Woods 6.Toburen 7.Sabol 8.Sanson

18. Which of the following definitions of an acid defines an acid as producing hydrogen ions? 1.Arrhenius 2.Bronsted-Lowry 3.Lewis 4.Kenzig 5.Woods 6.Toburen 7.Sabol 8.Sanson

19. Identify the conjugate base in the following equation. 1.NH 3 2.H 2 O 3.NH 4 + 4.OH-