chemistry Slide 1 of 42 23.3 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. Slide 2 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Aldehydes and Ketones Aldehydes and Ketones What is the structure of a carbonyl group found in aldehydes and ketones? Slide 3 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 4 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 5 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 6 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Aldehydes and Ketones Slide 7 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Aldehydes and Ketones Slide 8 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Aldehydes and Ketones Properties of Aldehydes and Ketones Slide 9 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 10 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Aldehydes and Ketones Vanillin, an aldehyde, comes from vanilla beans. Slide 11 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Aldehydes and Ketones A solvent used to remove nail polish is acetone, a ketone. Slide 12 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Carboxylic Acids Carboxylic Acids What is the general formula for a carboxylic acid? Slide 13 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 14 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 15 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Carboxylic Acids Carboxylic acids give a variety of foods— spoiled as well as fresh—a distinctive sour taste. Slide 16 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 17 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 18 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Carboxylic Acids Slide 19 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Esters What is the general structure of an ester? Slide 20 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Esters contain a carbonyl group and an ether link to the carbonyl carbon. The general formula for an ester is RCOOR. Slide 21 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 22 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Esters may be prepared from a carboxylic acid and an alcohol. Slide 23 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Slide 24 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Slide 25 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Ethyl ethanoate is a low-molar-mass ester. Slide 26 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Esters Esters impart the characteristic aromas and flavors of many flowers and fruits. Marigolds, raspberries, and bananas all contain esters. Slide 27 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Oxidation-Reduction Reactions Why is dehydrogenation an oxidation reaction? Slide 28 of 42 © Copyright Pearson Prentice Hall 23.3 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. Slide 29 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Slide 30 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Slide 31 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Slide 32 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Energy produced by oxidation reactions is used in both living and nonliving systems. Slide 33 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Slide 34 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Slide 35 of 42 © Copyright Pearson Prentice Hall 23.3 Carbonyl Compounds > Oxidation-Reduction Reactions Slide 36 of 42 © Copyright Pearson Prentice Hall 23.3 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 Cu2O, a red precipitate (right test tube). Slide 37 of 42 © Copyright Pearson Prentice Hall 23.3 Section Quiz. Assess students’ understanding of the concepts in Section 23.3. Continue to: -or- Launch: Section Quiz Slide 38 of 42 © Copyright Pearson Prentice Hall 23.3 Section Quiz 1. Which compound is a ketone? a. CH3COOH b. CH3CH2OH c. CH3CHO d. CH3COCH3 Slide 39 of 42 © Copyright Pearson Prentice Hall 23.3 Section Quiz. 2. The IUPAC name for the structure CH3CH2COOH is a. ethanoic acid. b. acetic acid. c. propanoic acid. d. propionic acid. Slide 40 of 42 © Copyright Pearson Prentice Hall 23.3 Section Quiz. 3. The product of the reaction between an alcohol and a carboxylic acid is called a. a ketone. b. an ether. c. an ester. d. an aldehyde. Slide 41 of 42 © Copyright Pearson Prentice Hall 23.3 Section Quiz. 4. Choose the correct words for the spaces. Dehydrogenation is __________ reaction because losing a molecule of hydrogen involves the _______________ electrons from the organic molecule. a. an oxidation, loss of two b. an oxidation, loss of four c. a reduction, gain of two d. a reduction, gain of four © Copyright Pearson Prentice Hall Slide 42 of 42 END OF SHOW