1. Chapter 25 Organic Chemistry I: Compounds

2. 2 Chapter Goals Saturated Hydrocarbons 1.Alkanes and Cycloalkanes 2.Naming Saturated Hydrocarbons Unsaturated Hydrocarbons 3.Alkenes 4.Alkynes Aromatic Hydrocarbons 5.Benzene 6.Other Aromatic Hydrocarbons 7.Hydrocarbons: A Summary

3. 3 Chapter Goals Functional Groups 8.Organic Halides 9.Alcohols and Phenols 10.Ethers 11.Aldehydes and Ketones 12.Amines 13.Carboxylic Acids 14.Some Derivatives of Carboxylic Acids 15.Summary of Functional Groups

4. 4 Chapter Goals Fundamental Classes of Organic Reactions 16.Substitution Reactions 17.Addition Reactions 18.Elimination Reactions 19.Polymerization Reactions

5. 5 Saturated Hydrocarbons  Hydrocarbons are chemical compounds that contain only C and H atoms.  Saturated hydrocarbons contain only single or sigma () bonds. There are no double or triple bonds in these compounds.  The primary source of hydrocarbons is petroleum and natural gas.

6. 6 Alkanes and Cycloalkanes  The simplest saturated hydrocarbons are called alkanes.  Methane, CH 4, is the simplest alkane.  The alkanes form a homologous series. Each member of the series differs by a specific number and kind of atoms.

7. 7 Alkanes and Cycloalkanes  The alkanes differ from each other by a CH 2 or methylene group.  All alkanes have this general formula. C n H 2n+2  For example ethane, C 2 H 6, and propane, C 3 H 8, are the next two family members.

8. 8 Alkanes and Cycloalkanes  Isomers are chemical compounds that have the same molecular formulas but different structures.  Two alkanes have the molecular formula C 4 H 10. They are a specific type of isomer called structural isomers.

9. 9 Alkanes and Cycloalkanes  Three alkanes have the formula C 5 H 12. There are three structural isomers of pentane.

10. 10 Alkanes and Cycloalkanes  Three alkanes have the formula C 5 H 12. There are three structural isomers of pentane.

11. 11 Alkanes and Cycloalkanes  Three alkanes have the formula C 5 H 12. There are three structural isomers of pentane.

12. 12 Alkanes and Cycloalkanes  There are five isomeric hexanes, C 6 H 14. You draw them!

13. 13 Alkanes and Cycloalkanes  There are five isomeric hexanes, C 6 H 14.

14. 14 Alkanes and Cycloalkanes  There are five isomeric hexanes, C 6 H 14.

15. 15 Alkanes and Cycloalkanes  There are five isomeric hexanes, C 6 H 14.

16. 16 Alkanes and Cycloalkanes  There are five isomeric hexanes, C 6 H 14.

17. 17 Alkanes and Cycloalkanes  The number of structural isomers increases rapidly with increasing numbers of carbon atoms.  The boiling points of the alkanes increase with molecular weight.

18. 18 Alkanes and Cycloalkanes  Cyclic saturated hydrocarbons are called cycloalkanes. They have the general formula C n H 2n.  Some examples are:

19. 19 Alkanes and Cycloalkanes  Cyclic saturated hydrocarbons are called cycloalkanes. They have the general formula C n H 2n.  Some examples are:

20. 20 Alkanes and Cycloalkanes  Cyclic saturated hydrocarbons are called cycloalkanes. They have the general formula C n H 2n.  Some examples are:

21. 21 Naming Saturated Hydrocarbons  The International Union of Pure and Applied Chemistry (IUPAC) names for the first 12 "straight-chain" or "normal" alkanes are given in this table. Number of carbon atoms in chain Name 1Methane 2Ethane 3Propane 4Butane 5Pentane 6Hexane

22. 22 Number of carbon atoms in chain Name 7Heptane 8Octane 9Nonane 10Decane 11Unidecane 12Dodecane Naming Saturated Hydrocarbons

23. 23 Naming Saturated Hydrocarbons  Other organic compounds are named as derivatives of the alkanes.  Branched-chain alkanes are named by the following rules. 1.Choose the longest continuous chain of carbon atoms which gives the basic name or stem.

24. 24 Naming Saturated Hydrocarbons 2Number each carbon atom in the basic chain, starting at the end that gives the lowest number to the first group attached to the main chain (substituent). 3For each substituent on the chain, we indicate the position in the chain (by an Arabic numeric prefix) and the kind of substituent (by its name).  The position of a substituent on the chain is indicated by the lowest number possible.  The number precedes the name of the substituent.

25. 25 Naming Saturated Hydrocarbons 4When there are two or more substituents of a given kind, use prefixes to indicate the number of substituents.  di = 2, tri = 3, tetra = 4, penta = 5, hexa = 6, hepta = 7, octa = 8, and so on. 5The combined substituent numbers and names serve as a prefix for the basic hydrocarbon name. 6Separate numbers from numbers by commas and numbers from words by hyphens.  Words are "run together".

26. 26 Naming Saturated Hydrocarbons  Alkyl groups (represented by the symbol R) are common substituents. Alkyl groups are fragments of alkanes in which one H atom has been removed for the connection to the main chain. Alkyl groups have the general formula C n H 2n+1.  In alkyl groups the -ane suffix in the name of the parent alkane is replaced by -yl. A one carbon group is named methyl. A two carbon group is named ethyl. A three carbon group is named propyl.

27. 27 Unsaturated Hydrocarbons  The three classes of unsaturated hydrocarbons are: 1.alkenes and cycloalkenes, C n H 2n 2.alkynes and cycloalkynes, C n H 2n-2 3.aromatic hydrocarbons

28. 28 Alkenes  The simplest alkenes contain one C=C bond per molecule. The general formula for simple alkenes is C n H 2n.  The first two alkenes are: ethene, C 2 H 4

29. 29 Alkenes  The simplest alkenes contain one C=C bond per molecule. The general formula for simple alkenes is C n H 2n.  The first two alkenes are: and propene, C 3 H 6

30. 30 Alkenes  Each doubly bonded C atom is sp 2 hybridized.  The sp 2 hybrid consists of: two  bonds (single bonds) and one  and one  bond (double bond)

31. 31 Alkenes  The systematic naming system for alkenes uses the same stems as alkanes.  In the IUPAC system, the -ane suffix for alkanes is changed to -ene. Common names for the alkenes have the same stem but use the suffix -ylene is used.  In chains of four or more C atoms, a numerical prefix shows the position of the lowest-numbered doubly bonded C atom. Always choose the longest chain that contains the C=C bond.

32. 32 Alkenes  Polyenes contain two or more double bonds per molecule.  Indicate the number of double bonds with suffixes: -adiene for two double bonds. -atriene for three double bonds, etc.  The positions of the substituents are indicated as for alkanes.  The position of the C=C bond(s) is/are given the lowest number(s) possible.

33. 33 Alkenes

34. 34 Alkenes

35. 35 Alkenes

36. 36 Cycloalkenes  Cycloalkenes have the general formula C n H 2n-2.  Examples are:  cyclopentene

37. 37 Cycloalkenes  cyclohexene

38. 38 Cycloalkenes  cycloheptene

39. 39 Alkynes  Alkynes contain C  C bonds.  The simplest alkyne is C 2 H 2, ethyne, or acetylene. Alkynes with only one C  C bond have the formula C n H 2n-2.  Each carbon atom in a C  C bond is sp hybridized. Each sp hybrid contains two  bonds and two  bonds. The carbon atom will have one single bond and one triple bond.

40. 40 Alkynes  Alkynes are named like the alkenes except that the suffix -yne is used with the characteristic stem The alkyne stem is derived from the name of the alkane with the same number of carbon atoms.

41. 41 Alkynes  Acetylene is an important industrial chemical. It is prepared by the reaction of calcium carbide with water.

42. 42 Alkynes  Acetylene burns in a highly exothermic reaction The combustion produces temperatures of about 3000°C. Acetylene is used in cutting torches for welding.  Alkynes are very reactive The two  bonds are sights of special reactivity.  Addition reactions, such as hydrogenation, are common.

43. 43 Hydrocarbons: A Summary Carbon Atom HybridizationC usesC formsExample sp 3 tetrahedral 4 sp 3 hybrids 4  bonds CH 4 sp 2 trigonal planar 3 sp 2 hybrids & 1p orbital 3  bonds 1  bond C2H4C2H4 sp linear 2 sp hybrids & 2 p orbitals 2  bonds 2  bonds C2H2C2H2

44. 44 Aromatic Hydrocarbons  Historically, aromatic was used to describe pleasant smelling substances.  Now it refers to benzene, C 6 H 6, and derivatives of benzene. Other compounds that have similar chemical properties to benzene are also called aromatic.

45. 45 Benzene  The structure of benzene, C 6 H 6, is:

46. 46 Other Aromatic Hydrocarbons  Coal tar is the common source of benzene and many other aromatic compounds.  Some aromatic hydrocarbons that contain fused rings are:  napthalene

47. 47 Other Aromatic Hydrocarbons  phenanthrene

48. 48 Other Aromatic Hydrocarbons  Many aromatic hydrocarbons contain alkyl groups attached to benzene rings (as well as to other aromatic rings).  The positions of the substituents on benzene rings are indicated by the prefixes: ortho-(o-) for substituents on adjacent C atoms meta-(m-) for substituents on C atoms 1 and 3 para-(p-) for substituents on C atoms 1 and 4

49. 49 Other Aromatic Hydrocarbons

50. 50 Functional Groups  Functional groups are groups of atoms that represent potential reaction sites.  Compounds that contain a given functional group usually undergo similar reactions.  Functional groups influence physical properties as well.

51. 51 Organic Halides  A halogen atom may replace almost any hydrogen atom in a hydrocarbon.  The functional group is the halide (-X) group.  Examples include: chloroform, CHCl 3

52. 52 Organic Halides  1,2-dichloroethane, ClCH 2 CH 2 Cl

53. 53 Organic Halides  para-dichlorobenzene

54. 54 Alcohols and Phenols  The functional group in alcohols and phenols is the hydroxyl (-OH) group.  Alcohols and phenols can be considered derivatives of hydrocarbons in which one or more H atoms have been replaced by -OH groups.  Phenols are derivatives of benzene in which one H has been replaced by replaced by -OH group.

55. 55 Alcohols and Phenols  Ethyl alcohol (ethanol), C 2 H 5 OH, is the most familiar alcohol.

56. 56 Alcohols and Phenols  Phenol, C 6 H 5 OH, is the most familiar phenol.

57. 57 Alcohols and Phenols  Alcohols are considered neutral compounds because they are only very slightly acidic. Alcohols can behave as acids but only in the presence of very strong bases.  Phenols are weakly acidic. K a  1.0 x 10 -10 for phenol Although phenols are very weakly acidic, they are also very corrosive.

58. 58 Alcohols and Phenols  Alcohols can be classified into three classes: 1.Primary (1°) alcohols like ethanol have the -OH group attached to a C atom that has one bond to another C atom.

59. 59 Alcohols and Phenols 2.Secondary(2°) alcohols have the –OH group attached to a C atom that has bonds to 2 other C atoms.  For example,2-propanol:

60. 60 Alcohols and Phenols 3.Tertiary (3°) alcohols have the –OH group attached to a C atom that is bonded to 3 other C atoms.  For example, 2-methyl-2-propanol

61. 61 Alcohols and Phenols  The stem for the parent hydrocarbon plus an -ol suffix is the systematic name for an alcohol.  A numeric prefix indicates the position of the -OH group in alcohols with three or more C atoms.  Common names are the name of the appropriate alkyl group plus alcohol.

62. 62 Alcohols and Phenols  Alcohols are named using the stem for the parent hydrocarbon plus an -ol suffix in the systematic nomenclature.  A numeric prefix indicates the position of the -OH group in alcohols with three or more C atoms. Common alcohol names are the name of the appropriate alkyl group plus the word alcohol.

63. 63 Alcohols and Phenols  There are several isomeric monohydric acyclic (contains no rings) alcohols that contain more than three C atoms.  There are four isomeric four-carbon alcohols.

64. 64 Alcohols and Phenols

65. 65 Alcohols and Phenols  There are eight isomeric five-carbon alcohols. You do it!

66. 66 Alcohols and Phenols  Polyhydric alcohols contain more than one -OH group per molecule.

67. 67 Alcohols and Phenols  Phenols are usually called by their common (trivial) names.

68. 68 Alcohols and Phenols  Phenols are usually called by their common (trivial) names.

69. 69 Alcohols and Phenols  Phenols are usually called by their common (trivial) names.

70. 70 Alcohols and Phenols  Phenols are usually called by their common (trivial) names.

71. 71 Alcohols and Phenols  Because the -OH group is quite polar, the properties of alcohols depend upon the number of -OH groups per molecule and the size of the organic group.  The boiling points of monohydric alcohols increase with increasing molecular weight.  The solubility of monohydric alcohols in water decrease with increasing molecular weight.  Polyhydric alcohols are more soluble in water because of the two or more polar groups (-OH).

72. 72 Ethers  Ethers may be thought of as derivatives of water in which both H atoms have been replaced by alkyl or aryl groups.

73. 73 Ethers  Ethers may be thought of as derivatives of water in which both H atoms have been replaced by alkyl or aryl groups.

74. 74 Ethers  Ethers may be thought of as derivatives of water in which both H atoms have been replaced by alkyl or aryl groups.

75. 75 Ethers  Ethers are not very polar and not very reactive.  They are excellent solvents.  Common names are used for most ethers.

76. 76 Aldehydes and Ketones  The functional group in aldehydes and ketones is the carbonyl group.

77. 77 Aldehydes and Ketones  Except for formaldehyde, aldehydes have one H atom and one organic group bonded to a carbonyl group.

78. 78 Aldehydes and Ketones  Ketones have two organic groups bonded to a carbonyl group.

79. 79 Aldehydes and Ketones  Common names for aldehydes are derived from the name of the acid with the same number of C atoms.  IUPAC names are derived from the parent hydrocarbon name by replacing -e with -al.

80. 80 Aldehydes and Ketones  Common names for aldehydes are derived from the name of the acid with the same number of C atoms.  IUPAC names are derived from the parent hydrocarbon name by replacing -e with -al.

81. 81 Aldehydes and Ketones  Common names for aldehydes are derived from the name of the acid with the same number of C atoms.  IUPAC names are derived from the parent hydrocarbon name by replacing -e with -al.

82. 82 Aldehydes and Ketones  The IUPAC name for a ketone is the characteristic stem for the parent hydrocarbon plus the suffix -one.  A numeric prefix indicates the position of the carbonyl group in a chain or on a ring.

83. 83 Aldehydes and Ketones  The IUPAC name for a ketone is the characteristic stem for the parent hydrocarbon plus the suffix -one.  A numeric prefix indicates the position of the carbonyl group in a chain or on a ring.

84. 84 Aldehydes and Ketones  The IUPAC name for a ketone is the characteristic stem for the parent hydrocarbon plus the suffix -one.  A numeric prefix indicates the position of the carbonyl group in a chain or on a ring.

85. 85 Aldehydes and Ketones  Many aldehydes and ketones occur in nature.

86. 86 Amines  Amines are derivatives of ammonia in which one or more H atoms have been replaced by organic groups (aliphatic or aromatic or a mixture of both).  There are three classes of amines.

87. 87 Amines  Amines are derivatives of ammonia in which one or more H atoms have been replaced by organic groups (aliphatic or aromatic or a mixture of both).  There are three classes of amines.

88. 88 Amines  Amines are derivatives of ammonia in which one or more H atoms have been replaced by organic groups (aliphatic or aromatic or a mixture of both).  There are three classes of amines.

89. 89 Amines  Amines are derivatives of ammonia in which one or more H atoms have been replaced by organic groups (aliphatic or aromatic or a mixture of both).  There are three classes of amines.

90. 90 Amines  Aniline is the simplest aromatic amine. It is much less basic than NH 3.  Aniline is a very important industrial chemical.

91. 91 Amines  Heterocylic amines have one or more N atoms in a ring structure.  Many are important in living systems.

92. 92 Amines  Heterocylic amines have one or more N atoms in a ring structure.  Many are important in living systems.

93. 93 Amines  Heterocylic amines have one or more N atoms in a ring structure.  Many are important in living systems.

94. 94 Carboxylic Acids  Carboxylic acids contain the carboxyl functional group.  The general formula for carboxylic acids is: R represents an alkyl or an aryl group

95. 95 Carboxylic Acids  IUPAC names for a carboxylic acid are derived from the name of the parent hydrocarbon. The final -e is dropped from the name of the parent hydrocarbon The suffix -oic is added followed by the word acid.  Many organic acids are called by their common (trivial) names which are derived from Greek or Latin.

96. 96 Carboxylic Acids

97. 97 Carboxylic Acids  Positions of substituents on carboxylic acid chains are indicated by numeric prefixes as in other compounds Begin the counting scheme from the carboxyl group carbon atom.  They are also often indicated by lower case Greek letters.  = 1 st C atom  = 2 nd C atom  = 3 rd C atom, etc.

98. 98 Carboxylic Acids

99. 99 Carboxylic Acids

100. 100 Carboxylic Acids

101. 101 Carboxylic Acids  Dicarboxylic acids contain two carboxyl groups per molecule.

102. 102 Nomenclature of Carboxylic Acids  Dicarboxylic acids contain two carboxyl groups per molecule.

103. 103 Nomenclature of Carboxylic Acids  Dicarboxylic acids contain two carboxyl groups per molecule.

104. 104 Carboxylic Acids  Aromatic acids are usually called by their common names.  Sometimes, they are named as derivatives of benzoic acid which is considered to be the "parent" aromatic acid.

105. 105 Carboxylic Acids

106. 106 Carboxylic Acids

107. 107 Carboxylic Acids  Acid strengths of simple carboxylic acids vary little with chain length.  However, substituents on a carbon atom in the chain can cause large variations in acid strengths.

108. 108 Carboxylic Acids

109. 109 Carboxylic Acids

110. 110 Carboxylic Acids  The -OH group in the carboxyl group of carboxylic acids, is displaced in many of their reactions.  The non -OH portion of a carboxylic acid is called an acyl group.

111. 111 Some Derivatives of Carboxylic Acids  Four important classes of compounds contain acyl groups They are all considered to be derivatives of carboxylic acids.  In these structures R's may represent either alkyl or aryl groups.

112. 112 Some Derivatives of Carboxylic Acids

113. 113 Some Derivatives of Carboxylic Acids

114. 114 Some Derivatives of Carboxylic Acids  Acid anhydrides are related to their parent acids as follows: The word anhydride means without water.

115. 115 Some Derivatives of Carboxylic Acids  Acyl halides are much more reactive, and more volatile, than their parent acids.  They react with water to form their parent acids and a hydrohalic acid.

116. 116 Some Derivatives of Carboxylic Acids  Acyl halides are prepared by reacting their parent acids with PCl 3, PCl 5, or SOCl 2.  The more volatile acid halide is then distilled out of the reaction mixture.

117. 117 Some Derivatives of Carboxylic Acids  Esters are prepared by heating a carboxylic acid with an alcohol in the presence of a small amount of an inorganic acid. The reaction mixture will contain some ester and water, as well as unreacted acid and alcohol.

118. 118 Some Derivatives of Carboxylic Acids  Esters are usually called by their common names.  Many simple esters occur naturally and have pleasant odors. Esters are frequently used in fragrances and as artificial flavors.

119. 119 Some Derivatives of Carboxylic Acids  Fats are solid esters of glycerol and (mostly) saturated acids at room temperature.  Oils are liquid esters of glycerol and primarily unsaturated acids at room temperature.  The "acid" parts of fats and oils usually contain even numbers of C atoms in naturally occurring fats and oils. 16 and 18 carbon chains are the most commonly found chain sizes in nature.

120. 120 Some Derivatives of Carboxylic Acids  Some acids that are found (as their esters) in fats and oils include:

121. 121 Some Derivatives of Carboxylic Acids  Stearic acid is often found in beef fat.

122. 122 Some Derivatives of Carboxylic Acids  Triglycerides are the triesters of glycerol.  The common name for triglycerides is tri (acid stem) plus an -in suffix. For example, tripalmitin.

123. 123 Some Derivatives of Carboxylic Acids  Waxes are esters of long chain fatty acids and alcohols other than glycerol. Commonly, waxes are derived from monohydric alcohols.  Beeswax and carnauba wax are esters of myricyl alcohol, C 30 H 61 OH.

124. 124 Some Derivatives of Carboxylic Acids  Carnauba wax is often used in car waxes.

125. 125 Some Derivatives of Carboxylic Acids  Dihydric alcohols (2 –OH’s per molecule) can react with dicarboxylic acids (2 –COOH’s per molecule) to form polyesters.  Ester linkages are formed at both ends of both molecules to give polymeric esters with very high molecular weights.

126. 126 Some Derivatives of Carboxylic Acids

127. 127 Some Derivatives of Carboxylic Acids  Amides are derivatives of organic acids and primary or secondary amines.  The functional groups of amides are:

128. 128 Some Derivatives of Carboxylic Acids  Amides are also named as derivatives of carboxylic acids.  The suffix -amide is substituted for -ic acid or -oic acid.

129. 129 Some Derivatives of Carboxylic Acids  When an aryl or alkyl substituent is present on the N atom, the letter N and the name of the substituent are prefixed to the name of the unsubstituted amide.

130. 130 Some Derivatives of Carboxylic Acids  Acetaminophen – “Tylenol” - is an amide.

131. 131 Summary of the Functional Groups  A summary of the functional groups is:

132. 132

133. 133 Substitution Reactions  In a substitution reaction an atom or group of atoms attached to a carbon atom is replaced (substituted for) by another atom or group of atoms. There is no change in the degree of saturation at the reactive carbon atom.  Halogenation reactions are an important class of substitution reactions. Chlorine reacts with alkanes in free radical chain reactions (also substitution reactions).

134. 134 Substitution Reactions  Free radical chain reactions The halogenation of methane is one example.

135. 135 Substitution Reactions

136. 136 Substitution Reactions

137. 137 Substitution Reactions  Free radical chain reactions Many substitution reactions of alkanes produce more than one product.

138. 138 Substitution Reactions

139. 139 Substitution Reactions

140. 140 Substitution Reactions  Nitration reaction of an aromatic hydrocarbon replaces an H atom attached to an aromatic ring with a nitro, -NO 2, group.

141. 141 Addition Reactions  An addition reaction involves an increase in the number of groups attached to carbon. The degree of saturation of the molecule is increased.

142. 142 Addition Reactions  Hydrogenation is a very important kind of addition reaction. Hydrogenation is used to convert unsaturated fats and oils to saturated fats or oils.

143. 143 Elimination Reactions  An elimination reaction involves the removal of groups attached to carbon. The degree of unsaturation increases.

144. 144 Elimination Reactions  Dehydration is an important kind of elimination reaction.

145. 145 Polymerization Reactions  A polymer is a large molecule that consists of a high-molecular weight chain of small molecules. The small molecules that have been joined to form the polymer are called monomers.  Synthetic polymers are a relatively new class of molecules. The first one, bakelite, was discovered in 1909. Nylon, which is still extensively used, was discovered in 1930’s.

146. 146 Polymerization Reactions  Addition polymerization is a large commercial process in the United States.  Polyethylene is the addition polymer made in the largest quantities in the United States. Polyethylene is used to make Coke bottles, plastic bags, etc.

147. 147 Polymerization Reactions  Addition polymerization Polyethylene formation

148. 148 Polymerization Reactions  Addition polymerization Teflon is the material used in nonstick frying pans and other kitchen utensils.

149. 149 Polymerization Reactions  Formation of rubber Natural rubber is a polymer made of isoprene (2-methyl- 1,3-butadiene) units that form a unique stereoisomeric structure.

150. 150 Polymerization Reactions  Vulcanization of rubber Natural rubber is a sticky, soft compound when heated which limited its commercial potential.  Charles Goodyear discovered in 1839 that heating rubber with sulfur removed the stickiness and made the substance elastic. This is the basis of modern tire production.  Vulcanization provides disulfide cross-linking bonds between the isoprene units.

151. 151 Polymerization Reactions  Copolymers If two different monomers are mixed and the polymerized, copolymers are formed.  Styrene butadiene rubber - SBR - is an important copolymer used in tire production.

152. 152 Polymerization Reactions  Copolymers

153. 153 Polymerization Reactions

154. 154 Polymerization Reactions  Condensation Polymers Condensation polymers occur when two molecules react and eliminate a small molecule. Molecules eliminated commonly are water and HCl.  Important condensation polymers include nylon, dacron, and kevlar. Dacron is used in clothing to make it wrinkle free. Blood does not clot in contact with dacron thus it is used in artificial arteries.

155. 155 Polymerization Reactions  Condensation Polymers Dacron formation

156. 156 Polymerization Reactions

157. 157 Polymerization Reactions  Condensation Polymers  Nylon was first made by Wallace Carothers in the 1930’s. Nylon is widely used in a variety of commercial products including stockings, rope, guitar strings, fire-proof clothing.

158. 158 Polymerization Reactions  Condensation Polymers Nylon 66 formation

159. 159 Polymerization Reactions

160. 160 Synthesis Question  TNT, the explosive ingredient in dynamite, has the correct name of 2,4,6-trinitrotoluene. Draw the structure of TNT.

161. 161 Synthesis Question

162. 162 Group Question  Aerobic respiration produces carbon dioxide and water as its end products. Anaerobic respiration has different end products. What are the end products of anaerobic respiration? How could you easily detect that someone has switched from aerobic to anaerobic respiration?

163. 163 End of Chapter 27  There are more organic compounds than any other type of chemical species.