1. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 11 Unsaturated Hydrocarbons 11.1 Alkenes and Alkynes 1

2. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Saturated Hydrocarbons Saturated hydrocarbons have the maximum number of hydrogen atoms attached to each carbon atom are alkanes and cycloalkanes with single C–C bonds CH 3 –CH 2 –CH 3 2

3. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Unsaturated Hydrocarbons Unsaturated hydrocarbons have fewer hydrogen atoms attached to the carbon chain than alkanes are alkenes with double bonds are alkynes with triple bonds 3 Ball-and-stick models of ethene and ethyne show functional groups of double or triple bonds and bond angles.

4. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Bond Angles in Alkenes and Alkynes According to VSEPR theory: the three groups bonded to carbon atoms in a double bond are at 120  angles alkenes are flat because the atoms in a double bond all lie in the same plane the two groups bonded to each carbon in a triple bond are at 180  angles 4

5. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Ethene (Ethylene ) Ethene, or ethylene, is the simplest alkene, with the formula C 2 H 4 has two carbon atoms connected by a double bond has two H atoms bonded to each C atom is flat, with all the C and H atoms in the same plane is a plant hormone used to accelerate the ripening of fruits 5

6. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Fragrant Alkenes The odors associated with the smell of lemons, oranges, roses, and lavender are due to volatile compounds that are synthesized by the plants. 6

7. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Ethyne (Acetylene) The simplest alkyne is ethyne, which has the common name of acetylene. 7 Acetylene is a fuel used in welding.

8. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Alkenes and Alkynes When the carbon chain of an alkene or alkyne has four or more C atoms, number the chain to give the lowest number to the first carbon in the double or triple bond. CH 2 =CH  CH 2  CH 3 1-butene 1 2 3 4 CH 3  CH=CH  CH 3 2-butene 1 2 3 4 CH 3  CH 2  C≡C  CH 3 2-pentyne 5 4 3 2 1 8

9. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Guide to Naming Alkenes and Alkynes 9

10. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Alkenes Using the IUPAC system, name the following compounds: CH 3 CH 3 CH 3 A. CH 3  CH  H 2 C=CH 2 B. H 2 C=CH  CH  CH  CH 3 Step 1 Name the longest carbon chain that contains the double bond. Use the ending ene for alkenes. CH 3 CH 3 CH 3 A. CH 3  CH  H 2 C=CH 2 B. H 2 C=CH  CH  CH  CH 3 butene pentene 10

11. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Alkenes Step 2 Number the longest carbon chain starting from the end nearer the double bond. CH 3 CH 3 CH 3 A. CH 3  CH  H 2 C=CH 2 B. H 2 C=CH  CH  CH  CH 3 1-butene 1-pentene Step 3 Give the location and name of each substituent (in alphabetical order) as a prefix to the alkene name. CH 3 CH 3 CH 3 A. CH 3  CH  H 2 C=CH 2 B. H 2 C=CH  CH  CH  CH 3 3-methyl-1-butene 3,4-dimethyl-1-pentene 11

12. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Alkynes Using the IUPAC system, name the following compound: CH 3 CH 3 HC C  CH  CH  CH 3 Step 1 Name the longest carbon chain that contains the triple bond. Use the ending yne for alkynes. CH 3 CH 3 HC C  CH  CH  CH 3 pentyne 12

13. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Alkynes Step 2 Number the longest carbon chain starting from the end nearer the triple bond. CH 3 CH 3 HC C  CH  CH  CH 3 1-pentyne Step 3 Give the location and name of each substituent (in alphabetical order) as a prefix to the alkyne name. CH 3 CH 3 HC C  CH  CH  CH 3 3,4-dimethyl-1-pentyne 13

14. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Write the IUPAC name for each of the following: A. CH 2 =CH  CH 2  CH 3 B. CH 3  CH=CH  CH 3 CH 3 C. CH 3  CH=C  CH 3 D. CH 3  C C  CH 3 14

15. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the IUPAC name for each of the following: A. CH 2 =CH  CH 2  CH 3 1-butene B. CH 3  CH=CH  CH 3 2-butene CH 3 C. CH 3  CH=C  CH 3 2-methyl-2-butene D. CH 3  C C  CH 3 2-butyne 15

16. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Write the IUPAC name for each of the following: A. CH 3  CH 2  CH 2  C C  CH 3 CH 3 B. CH 3  CH 2  C=CH  CH 3 16

17. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the IUPAC name for each of the following: A. CH 3  CH 2  CH 2  C C  CH 3 2-hexyne CH 3 B. CH 3  CH 2  C=CH  CH 3 3-methyl-2-pentene 17

18. Sample Problem 11.1 Naming Alkenes and Alkynes Solution Write the IUPAC name for each of the following: a. b. a. Step 1 Name the longest carbon chain that contains the double bond. There are five carbon atoms in the longest carbon chain containing the double bond. Replace the ane in the corresponding alkane name with ene to give pentene. Step 2 Number the carbon chain starting from the end nearer the double bond. Place the number of the first carbon in the double bond in front of the alkene name. Alkenes or alkynes with two or three carbons do not need numbers. For example, the double bond in ethene or propene must be between carbon 1 and carbon 2. Step 3 Give the location and name of each substituent (alphabetical order) as a prefix to the alkene name. The methyl group is located on carbon 4.

19. Sample Problem 11.1 Naming Alkenes and Alkynes Continued b. Step 1 Name the longest carbon chain that contains the triple bond. There are six carbon atoms in the longest chain containing the triple bond. Replace the ane in the corresponding alkane name with yne to give hexyne. Step 2 Number the carbon chain starting from the end nearer the triple bond. Place the number of the first carbon in the triple bond in front of the alkyne name. Step 3 Give the location and name of each substituent (alphabetical order) as a prefix to the alkyne name. There are no substituents in this formula. For cycloalkenes, the double bond is always between carbons 1 and 2. If there is a substituent, the ring is numbered from carbon 2 in the direction to give the lower number to the substituent. Study Check 11.1 Draw the condensed structural formula for each of the following: a. 2  pentyne b. 2  chloro  1  hexene

20. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 11 Unsaturated Hydrocarbons 11.2 Cis–Trans Isomers

21. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Cis and Trans Isomers In an alkene, the double bond is rigid holds attached groups in fixed positions makes cis–trans isomers possible 21

22. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Cis–Trans Isomers In cis–trans isomers, there is no rotation around the double bond in alkenes groups attached to the double bond are fixed relative to each other You can make a “double bond” with your fingers with both thumbs on the same side or opposite from each other. 22

23. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Cis–Trans Isomers Two isomers are possible when the groups attached to each side of the double bond are different. In a cis isomer, the alkyl groups are attached on one side of the double bond and H atoms are on the other side. In the trans isomer, the groups and H atoms are attached on opposite sides. 23 Ball-and-stick models of the cis and trans isomers of 2-butene.

24. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Cis–Trans Isomerism Alkenes cannot have cis–trans isomers if a carbon atom in the double bond is attached to identical groups. Identical 2-Bromopropene 1,1-Dibromoethene (not cis or trans) (not cis or trans) 24 H H H Br

25. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Cis–Trans Isomers in Nature Insects emit tiny quantities of pheromones, which are chemicals that send messages. The silkworm moth attracts other moths by emitting bombykol, which has one cis and one trans double bond. 25 Pheromones allow insects to attract mates from a great distance.

26. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Cis–Trans Isomers The prefix of cis or trans is placed in front of the alkene name when the compound is a cis or trans isomer. cis trans cis-1,2-dibromoethene trans-1,2-dibromoethene 26

27. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Name each, using cis or trans prefixes when needed. 27

28. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution cis-1,2-dibromoethene trans-2-butene 1,1-dichloropropene 28 Name each, using cis or trans prefixes when needed.

29. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Sample Problem 11.2 Identifying Cis–Trans Isomers a. This is a cis isomer because the two H atoms in the double bond are on the same side. The two-carbon alkene with a bromo group on carbon 1 and a chloro group on carbon 2 is named cis  1  bromo  2  chloroethene. b. This is a trans isomer because the two H atoms in the double bond are on the opposite sides of the double bond. The five-carbon alkene is named trans  2  pentene. Study Check 11.2 Is the following compound cis  3  hexene or trans  3  hexene? Solution Identify each of the following as the cis or trans isomer and give its name: a.b.

30. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 11 Unsaturated Hydrocarbons 11.3 Addition Reactions 30

31. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Addition Reactions In alkene and alkynes, the double or triple bond is easily broken, providing electrons to form new bonds double and triple bonds are very reactive in addition reactions, reactants are added to the carbon atoms in the double or triple bond 31

32. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Hydrogenation In hydrogenation, hydrogen atoms add to the carbon atoms of a double bond or triple bond a catalyst such as Pt or Ni is used to speed up the reaction 32

33. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Hydrogenation of Oils Adding H 2 to double bonds in vegetable oils produces compounds with higher melting points solids at room temperature, such as margarine, soft margarine, and shortening 33

34. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Write an equation for the hydrogenation of 1-butene using a platinum catalyst. 34

35. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write an equation for the hydrogenation of 1-butene using a platinum catalyst. Pt CH 2 =CH  CH 2  CH 3 + H 2 CH 3  CH 2  CH 2  CH 3 35

36. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Trans Fats The process of hydrogenation is used commercially to convert the double bonds in the unsaturated fats in vegetable oils to saturated fats such as margarine, which are more solid. Adjusting the amount of added hydrogen produces partially hydrogenated fats such as soft margarine, solid margarine in sticks, and shortenings, which are used in cooking. 36

37. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Write the product of each the following: Pt CH 3  CH=CH  CH 3 + H 2 Pt + H 2 37

38. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the product of each the following: Pt CH 3  CH=CH  CH 3 + H 2 CH 3  CH 2  CH 2  CH 3 Pt + H 2 38

39. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Sample Problem 11.3 Writing Equations for Hydrogenation In an addition reaction, hydrogen adds to the double or triple bond to give an alkane. a. b. c. Study Check 11.3 Draw the condensed structural formula of the product of the hydrogenation of 2  methyl  1  butene, using a platinum catalyst. Solution Draw the condensed structural formula for the product of each of the following hydrogenation reactions: a. b. c.

40. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Halogenation Reactions In halogenation reactions, halogen atoms such as chlorine or bromine add across a double bond the reaction occurs without a catalyst a dihaloalkane product results In the general equation for halogenation, X 2 is used for either Cl 2 or Br 2. 40

41. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Halogenation Reactions The addition reaction of Br 2 across a double bond is used to test for the presence of double bonds. A positive result turns a clear solution red. 41

42. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Sample Problem 11.4 Halogenation The addition of bromine to an alkene places a bromine atom on each of the carbon atoms of the double bond. Study Check 11.4 What is the name of the product formed when chlorine is added to 1  butene? Solution Draw the condensed structural formula of the product of the following reaction:

43. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Hydration In the addition reaction called hydration, an acid H + catalyst is required water (H−OH) adds to a double bond an H atom bonds to one C in the double bond an OH bonds to the other C an alkene is converted to an alcohol H OH H + CH 3  CH=CH  CH 3 + H  OH CH 3  CH  CH  CH 3 43

44. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Hydration When hydration occurs with a double bond that has an unequal number of H atoms, the H atom bonds to the C in the double bond with the more H the OH bonds to the C in the double bond with the fewer H atoms 44

45. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Write the product for the hydration of each of the following. H + 1. CH 3  CH 2  CH=CH  CH 2  CH 3 + HOH CH 3 H + 2. CH 3  C=CH  CH 2  CH 3 + HOH H + 3. + HOH 45

46. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the product for the hydration of each of the following. H + 1. CH 3  CH 2  CH=CH  CH 2  CH 3 + HOH H OH CH 3  CH 2  CH  CH  CH 2  CH 3 46

47. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the product for the hydration of each of the following. CH 3 H + 2. CH 3  C=CH  CH 2  CH 3 + HOH CH 3 CH 3  C  CH  CH 2  CH 3 OH H 47

48. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the product for the hydration of each of the following. H + 3. + HOH 48

49. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Sample Problem 11.5 Hydration The H– and –OH from water (HOH) add to the carbon atoms in the double bond. The H– adds to the carbon with more hydrogens, and the –OH bonds to the carbon with fewer hydrogen atoms. Study Check 11.5 Draw the condensed structural formula of the alcohol obtained by the hydration of 2  methyl  2  butene. Solution Draw the condensed structural formula of the product that forms in the following hydration reaction:

50. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 11 Unsaturated Hydrocarbons 11.4 Polymers of Alkenes 50

51. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Polymers Polymers are large, long-chain molecules found in nature, including cellulose in plants, starches in food, proteins, and DNA in the body also synthetic, such as polyethylene and polystyrene, Teflon, and nylon composed of small repeating units called monomers made from reaction of small alkenes 51

52. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Addition Reactions: Polymerization In polymerization, small repeating units called monomers join to form a long-chain polymer in an addition reaction. 52 monomer unit repeats n

53. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers 53 Synthetic polymers provide a wide variety of items that we use every day.

54. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers: Polyethylene Polyethylene is made using an addition reaction with the monomer unit ethylene. Common uses for polyethylene include plastic bottles, film, and insulation materials. 54

55. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers: Polytetrafluoroethylene Polytetrafluoroethylene, primarily used in nonstick coatings, is made using an addition reaction with the monomer unit of tetrafluoroethene. tetrafluoroethene polytetrafluoroethylene 55

56. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers: Polypropylene Polypropylene is used for ski and hiking clothing, carpets, and artificial joints. 56

57. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers: Polystyrene 57 Polystyrene is used for plastic coffee cups, cartons, and insulation.

58. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers: Polyvinylchloride Polyvinylchloride, also known as PVC, is used for plastic pipes and tubing, garden hoses, and garbage bags. 58

59. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Common Synthetic Polymers: Polydichloroethylene 59 Polydichloroethylene is used in plastic film and wraps.

60. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Name the starting monomer and give its structure for each of the following polymers: A. polyethylene B. polyvinylchloride C. polystyrene 60

61. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Name the starting monomer and give its structure for each of the following polymers: A. polyethylene ethene B. polyvinylchloride chloroethene C. polystyrene phenylethene, styrene 61

62. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Name the monomer used to make polypropylene, and write a portion of a polypropylene polymer using three monomers. 62

63. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Name the monomer used to make polypropylene, and write a portion of a polypropylene polymer using three monomers. 63

64. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Recycling Plastics Recycling is simplified by using codes on plastic items. 1 PETE Polyethylene terephtalate 2 HDPE High-density polyethylene 3 PV Polyvinyl chloride 4 LDPE Low-density polyethylene 5 PP Polypropylene 6 PS Polystyrene 7 OTHER Other plastic: fiberglass, polycarbonate, etc. 64

65. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check What types of plastic are indicated by the following codes? A. B. C. 65 3 PV 5 PP 6 PS

66. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution What types of plastic are indicated by the following codes? A. polyvinylchloride B.polypropylene C.polystyrene 66 3 PV 5 PP 6 PS

67. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Sample Problem 11.6 Polymers a. propene (propylene),b. 1,1-dichloroethene, Study Check 11.6 What is the condensed structural formula of the monomer used in the manufacturing of PVC? Solution Give the name and draw the condensed structural formula of the starting monomers for the following polymers: a. polypropyleneb.

68. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 11 Unsaturated Hydrocarbons 11.5 Aromatic Compounds 68

69. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Aromatic Compounds Benzene is an aromatic compound a ring of six C atoms and six H atoms a flat ring structure drawn with three double bonds represented by two structures because the electrons are shared among all the C atoms 69

70. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Benzene Structure Benzene has six electrons shared equally among the six C atoms is also represented as a hexagon with a circle drawn inside 70

71. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Aromatic Compounds in Nature and Health Vanillin Aspirin Ibuprofen Acetaminophen 71

72. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aromatic Compounds Aromatic compounds are named with benzene as the parent chain with one side group named in front of benzene methylbenzene chlorobenzene 72

73. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Some Common Names Some substituted benzene rings have common names that have been in use for many years with a single substituent use a common name or are named as a benzene derivative toluene aniline phenol (methylbenzene) (benzenamine) (hydroxybenzene) 73

74. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aromatic Compounds When two groups are attached to the benzene ring, the ring is numbered to give the lowest numbers to the side groups. 3-chlorotoluene 1,3-dichlorobenzene 2-chlorophenol 74

75. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Select the correct name for each compound. 1. A. chlorocyclohexane B. chlorobenzene C. 1-chlorobenzene 2. A. 1,2-dimethylbenzene B. 1,4-dimethylbenzene C. 1,3-dimethylbenzene 75

76. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Select the correct name for each compound. 1. B. chlorobenzene 2. C. 1,3-dimethylbenzene 76

77. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Write the structural formulas for each of the following: 1. 1,3-dichlorobenzene 2. 2-chlorotoluene 77

78. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Write the structural formulas for each of the following: 1. 1,3-dichlorobenzene 2. 2-chlorotoluene 78

79. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Identify the organic family for each: A. CH 3  CH 2  CH=CH 2 B. C. CH 3  C  CH D. 79

80. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Identify the organic family for each: A. CH 3  CH 2  CH=CH 2 alkene B. cycloalkane (alkane) C. CH 3  C  CH alkyne D. aromatic 80

81. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Concept Map – Unsaturated Hydrocarbons 81

82. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Sample Problem 11.7 Naming Aromatic Compounds A benzene ring with a methyl substituent is named toluene. The methyl group is attached to carbon 1 and the ring is numbered to give the lower numbers. Naming the substituents in alphabetical order, this aromatic compound is 4  bromo  3  chlorotoluene. Study Check 11.7 Name the following compound: Solution Give the IUPAC name for the following: