Carbonyl Compounds. Copyright Pearson Prentice Hall. What is the structure of a carbonyl group found in aldehydes and ketones?

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1 Carbonyl Compounds Have you heard of benzaldehyde or vanillin? It is likely that you have eaten these organic molecules, called aldehydes, in ice cream or cookies. You will read about the properties that are associated with carbonyl compounds, such as aldehydes. 1 of 42 Carbonyl Compounds > Aldehydes and Ketones Aldehydes and Ketones What is the structure of a carbonyl group found in aldehydes and ketones? 2 of 42 1

2 Carbonyl Compounds > Aldehydes and Ketones A carbonyl group is a functional group with the general structure C O. The C O functional group is present in aldehydes and ketones. 3 of 42 Carbonyl Compounds > Aldehydes and Ketones An aldehyde is an organic compound in which the carbon of the carbonyl group is always joined to at least one hydrogen. 4 of 42 2

3 Carbonyl Compounds > Aldehydes and Ketones A ketone is an organic compound in which the carbon of the carbonyl group is joined to two other carbons. 5 of 42 Carbonyl Compounds > Aldehydes and Ketones 6 of 42 3

4 Carbonyl Compounds > Aldehydes and Ketones 7 of 42 Carbonyl Compounds > Aldehydes and Ketones Properties of Aldehydes and Ketones 8 of 42 4

5 Carbonyl Compounds > Aldehydes and Ketones Uses of Aldehydes and Ketones Many aldehydes and ketones have distinctive odors. Aromatic aldehydes are often used as flavoring agents. Benzaldehyde is known as oil of bitter almond. Cinnamaldehyde is the source of the odor of oil of cinnamon. 9 of 42 Carbonyl Compounds > Aldehydes and Ketones Vanillin, an aldehyde, comes from vanilla beans. 10 of 42 5

6 Carbonyl Compounds > Aldehydes and Ketones A solvent used to remove nail polish is acetone, a ketone. 11 of 42 Carbonyl Compounds > Carboxylic Acids Carboxylic Acids What is the general formula for a carboxylic acid? 12 of 42 6

7 Carbonyl Compounds > Carboxylic Acids A carboxyl group consists of a carbonyl group attached to a hydroxyl group. A carboxylic acid is a compound with a carboxyl group. 13 of 42 Carbonyl Compounds > Carboxylic Acids The general formula for a carboxylic acid is RCOOH. Carboxylic acids are weak because they ionize slightly in solution to give a carboxylate ion and a hydrogen ion. 14 of 42 7

8 Carbonyl Compounds > Carboxylic Acids Carboxylic acids give a variety of foods spoiled as well as fresh a distinctive sour taste. 15 of 42 Carbonyl Compounds > Carboxylic Acids Low-molar-mass carboxylic acids are volatile liquids with sharp, unpleasant odors. The higher-mass carboxylic acids are nonvolatile, waxy, odorless solids with low melting points. 16 of 42 8

9 Carbonyl Compounds > Carboxylic Acids Many continuous-chain carboxylic acids were first isolated from fats and are called fatty acids. Stearic acid, an 18-carbon acid obtained from beef fat, is used to make inexpensive wax candles. 17 of 42 Carbonyl Compounds > Carboxylic Acids 18 of 42 9

10 Carbonyl Compounds > Esters Esters What is the general structure of an ester? 19 of 42 Carbonyl Compounds > Esters Esters contain a carbonyl group and an ether link to the carbonyl carbon. The general formula for an ester is RCOOR. 20 of 42 10

11 Carbonyl Compounds > Esters Esters are derivatives of carboxylic acids in which the OH of the carboxyl group has been replaced by an OR from an alcohol. 21 of 42 Carbonyl Compounds > Esters Esters may be prepared from a carboxylic acid and an alcohol. 22 of 42 11

12 Carbonyl Compounds > Esters 23 of 42 Carbonyl Compounds > Esters 24 of 42 12

13 Carbonyl Compounds > Esters Ethyl ethanoate is a low-molar-mass ester. 25 of 42 Carbonyl Compounds > Esters Esters impart the characteristic aromas and flavors of many flowers and fruits. Marigolds, raspberries, and bananas all contain esters. 26 of 42 13

14 Carbonyl Compounds > Oxidation-Reduction Reactions Oxidation-Reduction Reactions Why is dehydrogenation an oxidation reaction? 27 of 42 Carbonyl Compounds > Oxidation-Reduction Reactions The loss of hydrogen is a dehydrogenation reaction. Dehydrogenation is an oxidation reaction because the loss of each molecule of hydrogen involves the loss of two electrons from the organic molecule. 28 of 42 14

15 Carbonyl Compounds > Oxidation-Reduction Reactions 29 of 42 Carbonyl Compounds > Oxidation-Reduction Reactions 30 of 42 15

16 Carbonyl Compounds > Oxidation-Reduction Reactions 31 of 42 Carbonyl Compounds > Oxidation-Reduction Reactions Energy produced by oxidation reactions is used in both living and nonliving systems. 32 of 42 16

17 Carbonyl Compounds > Oxidation-Reduction Reactions 33 of 42 Carbonyl Compounds > Oxidation-Reduction Reactions 34 of 42 17

18 Carbonyl Compounds > Oxidation-Reduction Reactions 35 of 42 Carbonyl Compounds > Oxidation-Reduction Reactions An aldehyde is mixed with Fehling s reagent (left test tube) and heated. The blue copper(ii) ions in Fehling s reagent are reduced to form Cu 2 O, a red precipitate (right test tube). 36 of 42 18