1. Chapter Sixteen Carboxylic Acids, Esters, and Other Acid Derivatives

2. Chapter 16 | Slide 2 of 39 Fig. 16.1 The three simplest carboxylic acids: methanoic acid, ethanoic acid, and propanoic acid. Carboxylic Acids

3. Chapter 16 | Slide 3 of 39 →Fig. 16.2 Benzoic acid molecule Carboxylic Acids

4. Chapter 16 | Slide 4 of 39 Carboxylic acids contain the carboxyl group on carbon 1. A carboxyl group is a carbonyl attached to a hydroxyl Acts differently than an alcohol or a carbonyl compound O  CH 3 — C—OH= CH 3 —COOH carboxyl group Carboxylic Acids

5. Chapter 16 | Slide 5 of 39 Formula IUPAC Common alkan -oic acid prefix – ic acid HCOOH methanoic acid formic acid CH 3 COOH ethanoic acid acetic acid CH 3 CH 2 COOH propanoic acid propionic acid CH 3 CH 2 CH 2 COOH butanoic acid butyric acid Naming Carboxylic Acids

6. Chapter 16 | Slide 6 of 39 Identify longest chain containing the carboxyl group (IUPAC) Number carboxyl carbon as 1 (Common) Assign , ,  to carbon atoms adjacent to carboxyl carbon CH 3 | CH 3 — CH—CH 2 —COOH IUPAC 3-methylbutanoic acid Common  -methylbutryic acid Naming Rules

7. Chapter 16 | Slide 7 of 39 Aromatic Carboxylic Acids Benzoic Acid is the aromatic carboxylic acid Locates substituents by assigning 1 to the carbon with the carboxyl group Benzoic acid 3-chlorobenzoic acid 4-methylbenzoic acid

8. Chapter 16 | Slide 8 of 39

9. Chapter 16 | Slide 9 of 39

10. Chapter 16 | Slide 10 of 39 Properties of Carboxylic Acids Like alcohols, carboxylic acids form strong intermolecular hydrogen bonds. Most carboxylic acids exist as dimers. –Boiling points higher than alkanes of similar MW. –Small carboxylic acids (1-4 carbons) are soluble in water

11. Chapter 16 | Slide 11 of 39

12. Chapter 16 | Slide 12 of 39 Synthesis of Carboxylic Acids Synthesized from aromatic rings, primary alcohols and aldehydes. Carboxylic Acid

13. Chapter 16 | Slide 13 of 39 Oxidation of Aromatic Compounds Benzene does not react with KMnO 4. Alkyl groups on the ring (-R) are readily oxidized though. One product for all reactions.

14. Chapter 16 | Slide 14 of 39 Oxidation of Aromatic Compounds with KMnO 4

15. Chapter 16 | Slide 15 of 39 Oxidation of primary alcohols and aldehydes:

16. Chapter 16 | Slide 16 of 39 Oxidation of alcohols to carboxylic acids.

17. Chapter 16 | Slide 17 of 39 Carboxylic acids are weak acids –Stronger acids than alcohols CH 3 COOH + H 2 O CH 3 COO – + H 3 O + Neutralized by a base CH 3 COOH + NaOH CH 3 COO – Na + + H 2 O Properties

18. Chapter 16 | Slide 18 of 39 Carboxylic acids are obviously acidic. Stronger acids than alcohols, but weaker than mineral acids. Will react with NaOH to give metal carboxylates. There is a large range of acidities depending on the substituents on a carboxylic acid.

19. Chapter 16 | Slide 19 of 39 Carboxylate Ions The conjugate base of a carboxylic acid –Formed when a carboxylic acid loses a proton –Named by dropping the -ic acid ending and replacing it with –ate CH 3 CH 2 COO - Propionate CH 3 COO - Ethanoate (Acetate) CH 3 CH 2 CH 2 COO - Butanoate

20. Chapter 16 | Slide 20 of 39 Carboxylate Salts An ionic compound in which the negative ion is a carboxylate ion –Naming: the positive ion is named first, followed by a separate word giving the name of the negative ion –Converted back to a carboxylic acid by the addition of a strong acid CH 3 CH 2 COO - Na + Sodium Propionate CH 3 COO - K + Potassium Ethanoate CH 3 CH 2 CH 2 COO - Li + Lithium Butanoate

21. Chapter 16 | Slide 21 of 39 Table 16.3 Carboxylic Acids

22. Chapter 16 | Slide 22 of 39 ←Fig. 16.12 Methyl and ethyl esters of acetic acid. Esters

23. Chapter 16 | Slide 23 of 39 In an ester, the H in the carboxyl group is replaced with an alkyl group O  CH 3 — C—O —CH 3 = CH 3 —COO —CH 3 ester group Sulfur analogs of esters are called thioesters (sulfur replaces the hydroxyl oxygen) Ester

24. Chapter 16 | Slide 24 of 39 Name the alkyl from the alcohol –O- Name the acid with the C=O with –ate acidalcohol O  methyl CH 3 — C—O —CH 3 Ethanoate methyl ethanoate (IUPAC) (acetate)methyl acetate (common) Naming Esters

25. Chapter 16 | Slide 25 of 39

26. Chapter 16 | Slide 26 of 39 Esters

27. Chapter 16 | Slide 27 of 39 Reaction of a carboxylic acid and alcohol Acid catalyst O  H + CH 3 — C—OH + HO—CH 2 CH 3 O  CH 3 — C—O—CH 2 CH 3 + H 2 O Esterification: Preparation of Esters

28. Chapter 16 | Slide 28 of 39 Esters react with water and acid catalyst Split into carboxylic acid and alcohol O  H + H — C—O—CH 2 CH 3 + H 2 O O  H — C—OH + HO—CH 2 CH 3 Hydrolysis: Breaking Up Esters

29. Chapter 16 | Slide 29 of 39 Hydrolysis

30. Chapter 16 | Slide 30 of 39 Esters react with bases Produce the salt of the carboxylic acid and alcohol O  H 2 O CH 3 C—OCH 2 CH 3 + NaOH O  CH 3 C—O – Na + + HOCH 2 CH 3 salt of carboxylic acid Saponification reactions produce soaps Saponification

31. Chapter 16 | Slide 31 of 39 Soaps Carboxylate salts

32. Chapter 16 | Slide 32 of 39 The following figure represents soap. Which end of the anion is hydrophobic?

33. Chapter 16 | Slide 33 of 39 How does soap interact with grease?

34. Chapter 16 | Slide 34 of 39

35. Chapter 16 | Slide 35 of 39

36. Chapter 16 | Slide 36 of 39

37. Chapter 16 | Slide 37 of 39 Dicarboxylic Acids

38. Chapter 16 | Slide 38 of 39 The C 2 dicarboxylic acid, oxalic acid, contributes to the tart taste of rhubarb stalks.

39. Chapter 16 | Slide 39 of 39 Polyfunctional Carboxylic Acids Carboxylic acids that contain one or more additional functional groups –Unsaturated acids Contain a multiple bond –Hydroxy acids Contains an additional hydroxyl group –Keto acids Contains an additional carbonyl group Many monoacids and polyfunctional carboxylic acids are intermediates in metabolic reactions