1. Chapter 23 Functional Groups 23.3 Carbonyl Compounds
23.1 Introduction to Functional Groups
23.2 Alcohols, Ethers, and Amines
23.3 Carbonyl Compounds
23.4 Polymers
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

2. What gives a banana its characteristic smell?
CHEMISTRY & YOU
What gives a banana its characteristic smell?
Many organic molecules have pleasant aromas.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

3. What structural characteristic do an aldehyde and a ketone share?
Aldehydes and Ketones
Aldehydes and Ketones
What structural characteristic do an aldehyde and a ketone share?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

4. Aldehydes and Ketones
An oxygen atom can also be bonded to a single carbon atom by a double covalent bond.
A carbonyl group is a functional group with the general structure C O.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

5. The C O functional group is present in aldehydes and ketones.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

6. Aldehydes and Ketones
An aldehyde is an organic compound in which the carbon of the carbonyl group is joined to at least one hydrogen.
The general formula of an aldehyde is RCHO.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

7. Aldehydes and Ketones
A ketone is an organic compound in which the carbon of the carbonyl group is joined to two other carbons.
The general formula of a ketone is RCOR.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

8. The IUPAC system may be used for naming aldehydes and ketones.
First identify the longest carbon chain that contains the carbonyl group.
Replace the -e ending of the parent structure with -al to designate an aldehyde.
In the IUPAC system, the continuous chain aldehydes are named methanal, ethanal, propanal, butanal, and so forth.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

9. The IUPAC system may be used for naming aldehydes and ketones.
Ketones are named by changing the ending of the longest continuous carbon that contains the carbonyl group from -e to -one.
If the carbonyl group of a ketone could occur at more than one place on the chain, then its position is designated by the lowest possible number.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

10. IUPAC name (common name)
Interpret Data
Some Common Aldehydes
IUPAC name (common name)
Structural formula
Ball-and-stick model
Methanal (formaldehyde)
Ethanal (acetaldehyde)
Benzaldehyde (benzaldehyde)
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

11. IUPAC name (common name)
Interpret Data
Some Common Ketones
IUPAC name (common name)
Structural formula
Ball-and-stick model
Propanone (acetone)
Diphenylmethanone (benzophenone)
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

12. Uses of Aldehydes and Ketones
The simplest aldehyde is methanal (HCHO), also called formaldehyde.
Its greatest use is in the manufacture of synthetic resins.
A 40% aqueous solution of methanal, known as formalin, can be used to preserve biological specimens.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

13. Uses of Aldehydes and Ketones
The most common industrial ketone is propanone, also called acetone.
Propanone is used in industry as a solvent for resins, plastics, and varnishes.
Many nail-polish removers contain propanone as well.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

14. Uses of Aldehydes and Ketones
A wide variety of aldehydes and ketones have been isolated from plants and animals. Many have fragrant odors.
Benzaldehyde is also known as oil of bitter almond because it is largely responsible for the taste and aroma of almonds.
Many flavoring agents, including vanilla bean extract and cinnamon sticks, contain aromatic aldehydes.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

15. Properties of Aldehydes and Ketones
Aldehydes and ketones cannot form intermolecular hydrogen bonds because they lack —OH and —NH groups.
They have boiling points that are lower than those of corresponding alcohols.
Aldehydes and ketones can attract each other, however, through polar-polar interactions of their carbonyl groups.
Their boiling points are higher than those of the corresponding alkanes.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

16. Some Organic Compounds with Three Carbons
Interpret Data
Some Organic Compounds with Three Carbons
Compound
Formula
Boiling Point (°C)
Primary intermolecular interactions
Propane
CH3CH2CH3
–42
Dispersion forces
Propanal
CH3CH2CHO 49
Polar-polar interactions
Propanone
CH3COCH3 56
1-Propanol
CH3CH2CH2OH 97
Hydrogen bonding
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

17. Properties of Aldehydes and Ketones
Aldehydes and ketones can form weak hydrogen bonds between the carbonyl oxygen and the hydrogen atoms of water.
The lower members of the series—up to three carbons—are soluble in water in all proportions.
As the length of the hydrocarbon chain increases above four, however, water solubility decreases.
As might be expected, all aldehydes and ketones are soluble in nonpolar solvents.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

18. Why do aldehydes and ketones have similar properties?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

19. Why do aldehydes and ketones have similar properties?
Aldehydes and ketones have similar properties because each contains a C O functional group.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

20. What is the general formula of a carboxylic acid?
Carboxylic Acids
Carboxylic Acids
What is the general formula of a carboxylic acid?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

21. It can be written as —COOH or —CO2H.
Carboxylic Acids
A carboxyl group is a functional group that consists of a carbonyl group attached to a hydroxy group.
It can be written as —COOH or —CO2H.
A carboxylic acid is an organic compound with a carboxyl group.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

22. The general formula of a carboxylic acid is RCOOH.
Carboxylic Acids
The general formula of a carboxylic acid is RCOOH.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

23. Carboxylic Acids
Carboxylic acids are considered weak acids because they ionize weakly in solution.
In water, they can lose a hydrogen ion and form a carboxylate ion, as shown in the following reaction.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

24. Carboxylic Acids
In the IUPAC system, carboxylic acids are named by replacing the -e ending of the parent structure with the ending -oic acid.
Remember, the parent hydrocarbon of a carboxylic acid is the longest continuous carbon chain containing the carboxyl group.
The carboxylic acid CH3COOH
is named ethanoic acid.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

25. Some Saturated Aliphatic Carboxylic Acids
Interpret Data
Some Saturated Aliphatic Carboxylic Acids
Molecular formula
Carbon atoms
IUPAC name
Common name
Melting point (°C)
HCOOH 1
Methanoic acid
Formic acid 8
CH3COOH 2
Ethanoic acid
Acetic acid 17
CH3CH2COOH 3
Propanoic acid
Propionic acid
–22
CH3(CH2)2COOH 4
Butanoic acid
Butyric acid –6
CH3(CH2)4COOH 6
Hexanoic acid
Caproic acid –3
CH3(CH2)6COOH
Octanoic acid
Caprylic acid 16
CH3(CH2)8COOH 10
Decanoic acid
Capric acid 31
CH3(CH2)10COOH 12
Dodecanoic acid
Lauric acid 44
CH3(CH2)12COOH 14
Tetradecanoic acid
Myristic acid 58
CH3(CH2)14COOH
Hexadecanoic acid
Palmitic acid 63
CH3(CH2)16COOH 18
Octadecanoic acid
Stearic acid 70
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

26. Carboxylic Acids
Lemons and limes contain citric acid, a carboxylic acid that gives citrus fruits their sour flavor.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

27. Carboxylic Acids
Many carboxylic acids were first isolated from fats and are called fatty acids.
Propionic acid, the three-carbon acid, literally means first fatty acid.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

28. Like alcohols, carboxylic acids form intermolecular hydrogen bonds.
Thus, carboxylic acids have higher boiling and melting points than other compounds of similar molar mass.
The low-molar-mass members of the aliphatic carboxylic acid series are colorless, volatile liquids.
The higher members of the series are nonvolatile, waxy solids with low melting points.
All aromatic carboxylic acids are solids at room temperature.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

29. Carboxylic Acids
The carboxyl group in carboxylic acids is polar and readily forms hydrogen bonds with water molecules.
Methanoic, ethanoic, propanoic, and butanoic acids are completely soluble in water.
After four carbons, however, the solubility drops sharply.
Most carboxylic acids are also soluble in organic solvents such as ethanol or propanone.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

30. What is a fatty acid?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

31. A fatty acid is a carboxylic acid that was first isolated from fats.
What is a fatty acid?
A fatty acid is a carboxylic acid that was first isolated from fats.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

32. Oxidation-Reduction Reactions
Why is dehydrogenation classified as an oxidation reaction?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

33. Oxidation-Reduction Reactions
The classes of organic compounds you have just studied—aldehydes, ketones, and carboxylic acids—are related by oxidation and reduction reactions.
Oxidation is the gain of oxygen, loss of hydrogen, or loss of electrons.
Reduction is the loss of oxygen, gain of hydrogen, or gain of electrons.
One does not occur without the other.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

34. Oxidation-Reduction Reactions
In organic chemistry, the number of oxygen atoms and hydrogen atoms attached to carbon indicates the degree of oxidation of a compound.
The fewer hydrogens on a carbon-carbon bond, the more oxidized the bond.
Thus, a triple bond is more oxidized than a double bond, which is more oxidized than a single bond.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

35. Oxidation-Reduction Reactions
The loss of a molecule of hydrogen from an organic molecule is called a dehydrogenation reaction.
It is the opposite of a hydrogenation reaction.
Strong heating and a catalyst are usually needed to make dehydrogenation reactions occur.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

36. Oxidation-Reduction Reactions
Dehydrogenation is an oxidation reaction because the loss of each molecule of hydrogen involves the loss of two electrons from the organic molecule.
The remaining carbon electrons pair to make a second or third bond.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

37. Oxidation-Reduction Reactions
Oxidation in organic chemistry also involves the number and degree of oxidation of oxygen atoms attached to the carbon atom.
Methane, a saturated hydrocarbon, can be oxidized in steps to carbon dioxide.
Methane is oxidized to methanol, then to methanal, then to methanoic acid, and finally to carbon dioxide.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

38. Oxidation-Reduction Reactions
The more reduced a carbon compound is, the more energy it can release upon its complete oxidation to carbon dioxide.
The oxidation of organic compounds is exothermic.
The energy-releasing properties of oxidation reactions are extremely important for the production of energy in living systems.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

39. Oxidation-Reduction Reactions
Primary alcohols can be oxidized to aldehydes.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

40. Oxidation-Reduction Reactions
Secondary alcohols can be oxidized to ketones by warming them with acidified potassium dichromate (K2Cr2O7).
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

41. Oxidation-Reduction Reactions
Tertiary alcohols, however, cannot be oxidized because there is no hydrogen atom present on the carbon atom attached to the hydroxy group.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

42. Oxidation-Reduction Reactions
Aldehydes are so easily oxidized that it is difficult to prevent further oxidation to carboxylic acids.
Further oxidation is avoided by removing aldehydes from the reaction mixture as they are formed.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

43. Oxidation-Reduction Reactions
Tests for aldehydes make use of the ease with which these compounds are oxidized.
Benedict’s and Fehling’s reagents are deep-blue alkaline solutions of copper(II) sulfate.
When an aldehyde is oxidized with Benedict’s or Fehling’s reagent, a red precipitate of copper(I) oxide is formed.
The aldehyde is oxidized to its acid, and copper (II) ions are reduced to copper(I) ions.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

44. What hydrocarbon can be oxidized to form aldehydes
What hydrocarbon can be oxidized to form aldehydes? What hydrocarbon can be oxidized to ketones?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

45. What hydrocarbon can be oxidized to form aldehydes
What hydrocarbon can be oxidized to form aldehydes? What hydrocarbon can be oxidized to ketones?
A primary alcohol can be oxidized to an aldehyde. A secondary alcohol can be oxidized to a ketone.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

46. What is the general formula of an ester?
Esters
Esters
What is the general formula of an ester?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

47. Esters
Esters are probably the most pleasant and delicious organic compounds one can study.
Many esters have pleasant, fruity odors.
Esters give blueberries, pineapples, apples, pears, bananas, and many other
fruits their characteristic aromas.
They also give many perfumes
their fragrances.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

48. Esters
An ester is an organic compound in which the —OH of the carboxyl group has been replaced by an —OR from an alcohol.
Esters contain a carbonyl group and an ether link to the carbonyl carbon.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

49. The general formula of an ester is RCOOR.
Esters
The general formula of an ester is RCOOR.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

50. CHEMISTRY & YOU
The smell of strawberries is largely due to benzyl acetate. The smell of almonds is largely due to benzaldehyde. How are the general formulas of these compounds similar? How are they different?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

51. CHEMISTRY & YOU
The smell of strawberries is largely due to benzyl acetate. The smell of almonds is largely due to benzaldehyde. How are the general formulas of these compounds similar? How are they different?
Benzyl acetate and benzaldehyde each contain a benzene ring. Benzyl acetate contains an ester group, while benzaldehyde contains an aldehyde group.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

52. Esters
Although ester molecules are polar, they cannot form hydrogen bonds with one another.
They do not contain hydrogen attached to oxygen or another electronegative atom.
As a result, only weak attractions hold ester molecules to one another.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

53. Esters
Although ester molecules are polar, they cannot form hydrogen bonds with one another.
They do not contain hydrogen attached to oxygen or another electronegative atom.
As a result, only weak attractions hold ester molecules to one another.
Esters have much lower boiling points than carboxylic acids.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

54. Esters
Although ester molecules are polar, they cannot form hydrogen bonds with one another.
The low-molar-mass esters are somewhat soluble in water, but esters containing more than four or five carbons have very limited solubility.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

55. Esters may be prepared from a carboxylic acid and an alcohol.
The process is called esterification.
The reactants, usually a carboxylic acid and a primary or secondary alcohol, are heated with an acid as a catalyst.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

56. Esters
If an ester is heated with water for several hours, usually very little happens.
In strong acid or base solutions, however, the ester breaks down.
An ester is hydrolyzed by the addition of water to produce a carboxylic acid and an alcohol.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

57. Hydroxide ions also promote this reaction.
Esters
Hydroxide ions also promote this reaction.
Because many esters do not dissolve in water, a solvent such as ethanol is added to make the solution homogeneous.
The reaction mixture is usually heated.
All of the ester is converted to products.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

58. If the reaction mixture is acidified, the carboxylic acid forms.
Esters
If the reaction mixture is acidified, the carboxylic acid forms.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

59. What are reactants in an esterification reaction? What are the products?
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

60. What are reactants in an esterification reaction? What are the products?
The reactants in an esterification reaction are a carboxylic acid and an alcohol. The products are an ester and water.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

61. The C O functional group is present in aldehydes and ketones.
Key Concepts
The C O functional group is present in aldehydes and ketones.
The general formula of a carboxylic acid is RCOOH.
Dehydrogenation is an oxidation reaction because the loss of each molecule of hydrogen involves the loss of two electrons from the organic molecule.
The general formula of an ester is RCOOR.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

62. Glossary Terms
carbonyl group: a functional group having a carbon atom and an oxygen atom joined by a double bond; it is found in aldehydes, ketones, esters, and amides
aldehyde: an organic compound in which the carbon of the carbonyl group is joined to at least one hydrogen; the general formula is RCHO
ketone: an organic compound in which the carbon of the carbonyl group is joined to two other carbons; the general formula is RCOR
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

63. Glossary Terms
carboxyl group: a functional group consisting of a carbonyl group attached to a hydroxyl group; it is found in carboxylic acids
carboxylic acid: an organic acid containing a carboxyl group; the general formula is RCOOH
fatty acid: the name given to continuous-chain carboxylic acids that were first isolated from fats
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

64. dehydrogenation reaction: a reaction in which hydrogen is lost
Glossary Terms
dehydrogenation reaction: a reaction in which hydrogen is lost
ester: a derivative of a carboxylic acid in which the —OH of the carboxyl group has been replaced by the —OR from an alcohol; the general formula is RCOOR
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

65. Carbon Chemistry and Reactions
BIG IDEA
Carbon Chemistry and Reactions
Chemical reactions can be used to change the structure of organic molecules, often by introducing a new functional group.
Oxidation-reduction reactions are commonly used in organic chemistry.
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

66. END OF 23.3
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.