Chapter 12 Saturated Hydrocarbons PDF

Chapter 12 Saturated Hydrocarbons  Chapter 12 Chapter Outline 12.1 Organic and inorganic compounds 12.2 Bonding characteristics of the carbon atom 12.3 Hydrocarbons and hydrocarbon derivatives 12.4 Alkanes: Acyclic saturat...

Chapter 12 Saturated Hydrocarbons  Chapter 12 Chapter Outline 12.1 Organic and inorganic compounds 12.2 Bonding characteristics of the carbon atom 12.3 Hydrocarbons and hydrocarbon derivatives 12.4 Alkanes: Acyclic saturated hydrocarbons 12.5 Structural formulas 12.6 Alkane isomerism 12.7 Conformations of alkanes 12.8 IUPAC nomenclature of alkanes 12.9 Line-angle structural formulas for alkanes 12.10 Classification of carbon atoms 12.11 Branched-chain alkyl groups 12.12 Cycloalkanes 12.13 IUPAC nomenclature for cycloalkanes 12.14 Isomerism in cycloalkanes 12.15 Sources of alkanes and cycloalkanes 12.16 Physical properties of alkanes and cycloalkanes 12.17 Chemical properties of alkanes and cycloalkanes 12.18 Halogenated alkanes and cycloalkanes Copyright ©2016 Cengage Learning. All Rights Reserved. 2  Section 12.1 Organic and Inorganic Compounds Main Branches of Chemistry Organic chemistry: Study of hydrocarbons and their various derivatives Inorganic chemistry: Study of all substances other than hydrocarbons and their derivatives Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 3  Section 12.1 Organic and Inorganic Compounds Organic chemistry is the study of? a.All the compounds formed by all the elements. b.All hydrocarbons and their derivatives. c.Compounds made up of carbon and hydrogen and derivatives of these compounds. d.Both (b) and (c). Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 4  Section 12.1 Organic and Inorganic Compounds Organic chemistry is the study of? a.All the compounds formed by all the elements. b.All hydrocarbons and their derivatives. c.Compounds made up of carbon and hydrogen and derivatives of these compounds. d.Both (b) and (c). Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 5  Section 12.2 Bonding Characteristics of the Carbon Atom Carbon (C) atom makes total 4 bonds The sharing of four valance electrons requires the formation of four covalent bonds which are represented by four lines C C Four single bonds Two single bonds and one double bond C C Two double bonds One triple bond and one single bond Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 6  Section 12.2 Bonding Characteristics of the Carbon Atom The bonding characteristics of the carbon atom is (are)? a.Carbon bonds to four other atoms by single bonds. b.Carbon bonds to three other atoms by two single bonds and a double bond. c.Carbon bonds to two other atoms by either two double bonds or a single bond and a triple bond. d.All of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 7  Section 12.2 Bonding Characteristics of the Carbon Atom The bonding characteristics of the carbon atom is (are)? a.Carbon bonds to four other atoms by single bonds. b.Carbon bonds to three other atoms by two single bonds and a double bond. c.Carbon bonds to two other atoms by either two double bonds or a single bond and a triple bond. d.All of these. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 8  Section 12.3 Hydrocarbons and Hydrocarbon Derivatives Hydrocarbon: Compound that contains only carbon and hydrogen atoms Hydrocarbon derivative: Compound that contains carbon and hydrogen and one or more additional elements Saturated hydrocarbon: Hydrocarbon in which all carbon–carbon bonds are single bonds Unsaturated hydrocarbon: Hydrocarbon with one or more carbon–carbon multiple bonds – Double bonds, triple bonds, or both Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 9  Section 12.3 Hydrocarbons and Hydrocarbon Derivatives Figure 12.2 - Summary of Classification Terms for Organic Compounds Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 10  Section 12.3 Hydrocarbons and Hydrocarbon Derivatives Hydrocarbons consist of what two classes of hydrocarbons? a.Saturated and unsaturated hydrocarbons. b.Organic compounds and hydrocarbon derivatives. c.Acyclic and cyclic hydrocarbons. d.Alkenes and alkynes. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 11  Section 12.3 Hydrocarbons and Hydrocarbon Derivatives Hydrocarbons consist of what two classes of hydrocarbons? a.Saturated and unsaturated hydrocarbons. b.Organic compounds and hydrocarbon derivatives. c.Acyclic and cyclic hydrocarbons. d.Alkenes and alkynes. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 12  Section 12.4 Alkanes: Acyclic Saturated Hydrocarbons Alkane: Saturated hydrocarbon in which the carbon atom arrangement is acyclic All bonds are carbon–carbon single bonds General formula - CnH2n+2 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 13  Section 12.4 Alkanes: Acyclic Saturated Hydrocarbons The molecular formula for all alkanes is: a. CnH2n b. CnH2n+2 c. CnH2n-2 d. CnH2n+4 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 14  Section 12.4 Alkanes: Acyclic Saturated Hydrocarbons The molecular formula for all alkanes is: a. CnH2n b. CnH2n+2 c. CnH2n-2 d. CnH2n+4 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 15  Section 12.5 Structural Formulas Expanded structural formula: A two-dimensional structural representation that depicts the bonding of all atoms in a molecule Condensed structural formula: Structural arrangements of different groupings in a molecule Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 16  Section 12.5 Structural Formulas Skeletal structural formula: Structural arrangement of all bonded carbon atoms without showing the attached hydrogen atoms Consider the following formula – It can be abbreviated as: Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 17  Section 12.5 Structural Formulas The formula CH3–CH2–CH3 is an example of what type of formula? a. Structural formula b. Expanded structural formula c. Condensed structural formula d. Skeletal structural formula Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 18  Section 12.5 Structural Formulas The formula CH3–CH2–CH3 is an example of what type of formula? a. Structural formula b. Expanded structural formula c. Condensed structural formula d. Skeletal structural formula Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 19  Section 12.6 Alkane Isomerism Structural Isomerism Isomers: Compounds having same molecular formula but different structural arrangements – The phenomenon is known as isomerism Continuous-chain alkane: Carbon atoms are connected in a continuous non-branching chain Branched-chain alkane: One or more branches of carbon atoms are attached to a continuous chain Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 20  Section 12.6 Alkane Isomerism Structural (Constitutional) Isomerism Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 21  Section 12.6 Alkane Isomerism Structural (Constitutional) Isomerism Constitutional isomers: Isomers that differ in connectivity of atoms Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 22  Section 12.6 Alkane Isomerism Table 12.1 - Number of Isomers Possible for Alkanes of Various Carbon Chain Lengths Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 23  Section 12.6 Alkane Isomerism What are isomers? a. Compounds that have different molecular formulas but the same structural formula. b. Compounds that have the same molecular formula but different structural formulas. c. Compounds that have the same molecular formula and same structural formula. d. Compounds that have different molecular and structural formulas. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 24  Section 12.6 Alkane Isomerism What are isomers? a. Compounds that have different molecular formulas but the same structural formula. b. Compounds that have the same molecular formula but different structural formulas. c. Compounds that have the same molecular formula and same structural formula. d. Compounds that have different molecular and structural formulas. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 25  Section 12.7 Conformations of Alkanes Conformation: The specific three-dimensional spatial arrangement of atoms in an organic molecule at a given instant that results from rotations about C–C single bonds Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 26  Section 12.7 Conformations of Alkanes Which of the following best describes conformation in organic chemistry? a. Conformation represents the method used to draw an organic compound on paper. b. Conformation represents the two-dimensional arrangement of atoms. c. Conformation represents the three-dimensional arrangement of atoms at any given time as a result of rotation around the carbon-carbon single bond. d. Conformation represents the three-dimensional arrangement of atoms at any given time as a result of the rigid nature of the carbon-carbon single bond. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 27  Section 12.7 Conformations of Alkanes Which of the following best describes conformation in organic chemistry? a. Conformation represents the method used to draw an organic compound on paper. b. Conformation represents the two-dimensional arrangement of atoms. c. Conformation represents the three-dimensional arrangement of atoms at any given time as a result of rotation around the carbon-carbon single bond. d. Conformation represents the three-dimensional arrangement of atoms at any given time as a result of the rigid nature of the carbon-carbon single bond. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 28  Section 12.8 IUPAC Nomenclature for Alkanes A systematic approach for naming alkanes introduced by the International Union of Pure and Applied Chemistry (IUPAC) Rules apply to both types of alkanes – Continuous chain alkanes – Branched chain alkanes Substituent: An atom or group of atoms attached to a chain (or ring) of carbon atoms Alkyl group: The group of atoms that would be obtained by removing a hydrogen atom from an alkane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 29  Section 12.8 IUPAC Nomenclature for Alkanes A _____ is an atom or group of atoms attached to a chain of carbon atoms and an ______ is the group of atoms formed by the removal of a hydrogen atom from an alkane. a. resonant; alkane group b. substituent; alkyl group c. constituent; allyl group d. constant; acidic group Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 30  Section 12.8 IUPAC Nomenclature for Alkanes A _____ is an atom or group of atoms attached to a chain of carbon atoms and an ______ is the group of atoms formed by the removal of a hydrogen atom from an alkane. a. resonant; alkane group b. substituent; alkyl group c. constituent; allyl group d. constant; acidic group Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 31  Section 12.8 IUPAC Nomenclature for Alkanes Rules for Naming Branched-Chain Alkanes Rule 1 – Identify the longest continuous carbon chain and name it Rule 2 – Number the carbon atoms in the parent chain from the end of the chain nearest a substituent Rule 3 – If only one substituent is present, name and locate it by number, and prefix the number and name to that of the parent carbon chain Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 32  Section 12.8 IUPAC Nomenclature for Alkanes Rules for Naming Branched-Chain Alkanes Rule 4 – If two or more of the same kind of alkyl group are present in a molecule, indicate the number with a Greek numerical prefix (di-, tri-, tetra-, penta-, and so forth). In addition, a number specifying the location of each identical group must be included. These position numbers, separated by commas, precede the numerical prefix. Numbers are separated from words by hyphens Rule 5 – When two kinds of alkyl groups are present on the same carbon chain, number each group separately, and list the names of the alkyl groups in alphabetical order Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 33  Section 12.8 IUPAC Nomenclature for Alkanes Rules for Naming Branched-Chain Alkanes Rule 6 – Follow IUPAC punctuation rules Separate numbers from each other by commas Separate numbers from letters by hyphens Do not add a hyphen or a space between the last-named substituent and the name of the parent alkane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 34  Section 12.8 IUPAC Nomenclature for Alkanes Practice Exercise Give the IUPAC name for each of the following alkanes. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 35  Section 12.8 IUPAC Nomenclature for Alkanes Practice Exercise Give the IUPAC name for each of the following alkanes. Answer: a. 3,6-Dimethyloctane b. 3,4,4,5-Tetramethyloctane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 36  Section 12.8 IUPAC Nomenclature for Alkanes Which of the following is the first rule of the IUPAC method of naming branched chain alkanes? a. Identify the longest straight chain of carbons in a straight line and name the chain. b. Identify the longest continuous carbon chain which may or may not be in a straight line and name the chain. c. Number the longest carbon chain from the end furthest from the branch. d. Number the longest carbon chain from the end nearest the branch. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 37  Section 12.8 IUPAC Nomenclature for Alkanes Which of the following is the first rule of the IUPAC method of naming branched chain alkanes? a. Identify the longest straight chain of carbons in a straight line and name the chain. b. Identify the longest continuous carbon chain which may or may not be in a straight line and name the chain. c. Number the longest carbon chain from the end furthest from the branch. d. Number the longest carbon chain from the end nearest the branch. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 38  Section 12.9 Line-Angle Structural Formulas for Alkanes Line-Angle Structural Formula A structural representation in which a line represents a carbon–carbon bond A carbon atom is understood to be present: – At every point where two lines meet – At the ends of lines – Example Pentane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 39  Section 12.9 Line-Angle Structural Formulas for Alkanes Line-Angle Structural Formulas Used to designate the structures of branched-chain alkanes – Example - The five constitutional isomers of C6H14 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 40  Section 12.9 Line-Angle Structural Formulas for Alkanes The following structure represents: a.The expanded structure of an alkane. b.The expanded structure of a branched chain alkane. c.The line-angle structural formula of a branched chain alkane. d.The line-angle structural formula of an alkane. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 41  Section 12.9 Line-Angle Structural Formulas for Alkanes The following structure represents: a.The expanded structure of an alkane. b.The expanded structure of a branched chain alkane. c.The line-angle structural formula of a branched chain alkane. d.The line-angle structural formula of an alkane. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 42  Section 12.10 Classification of Carbon Atoms Primary carbon atom: A carbon atom directly bonded to one other carbon atom Secondary carbon atom: A carbon atom directly bonded to two other carbon atoms Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 43  Section 12.10 Classification of Carbon Atoms Tertiary carbon atom: A carbon atom directly bonded to three other carbon atoms Quaternary carbon atom: A carbon atom directly bonded to four other carbon atoms Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 44  Section 12.10 Classification of Carbon Atoms Carbon atoms are classified as primary, secondary, tertiary, and quaternary and contain __, __, __, and __ hydrogen atoms, respectively. a. 0, 1, 2, 4 b. 3, 2, 1, 0 c. 4, 3, 2, 1 d. 1, 2, 3, 4 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 45  Section 12.10 Classification of Carbon Atoms Carbon atoms are classified as primary, secondary, tertiary, and quaternary and contain __, __, __, and __ hydrogen atoms, respectively. a. 0, 1, 2, 4 b. 3, 2, 1, 0 c. 4, 3, 2, 1 d. 1, 2, 3, 4 Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 46  Section 12.11 Branched-Chain Alkyl Groups Continuous-chain alkyl groups: The simplest type of alkyl groups with a continuous chain of carbon atoms Branched-chain alkyl groups: Alkyl groups are added to the continuous parent chain of carbon atoms (alkenes with branched-chain alkyl groups) Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 47  Section 12.11 Branched-Chain Alkyl Groups IUPAC Naming A hyphen always follows the designations, secondary and tertiary, but no hyphen is used with the prefix iso Examples – Secondary-butyl – Tertiary-butyl – Isobutyl Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 26  Section 12.11 Branched-Chain Alkyl Groups IUPAC Naming Rules Rule 1 – The longest continuous carbon chain that begins at the point of attachment of the alkyl group becomes the base name Rule 2 – The base chain is numbered at the point of attachment Rule 3 – Substituents on the base chain are listed in alphabetical order, using numerical prefixes when necessary, and substituent locations are designated using numbers Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 49  Section 12.11 Branched-Chain Alkyl Groups IUPAC Naming Rules The group –CH2-CH2-CH3 is known as the _____ alkyl group, while the group CH3 CH CH3 is known as the _____ alkyl group. a. butyl; isopropyl b. propyl; primary propyl c. propyl; isopropyl d. butyl; primary butyl Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 50  Section 12.11 Branched-Chain Alkyl Groups IUPAC Naming Rules The group –CH2-CH2-CH3 is known as the _____ alkyl group, while the group CH3 CH CH3 is known as the _____ alkyl group. a. butyl; isopropyl b. propyl; primary propyl c. propyl; isopropyl d. butyl; primary butyl Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 51  Section 12.12 Cycloalkanes Cycloalkane: A saturated hydrocarbon in which carbon atoms connected to one another in a cyclic (ring) arrangement are present The general formula is CnH2n Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 52  Section 12.12 Cycloalkanes The structure is known as a : a. cyclicpentane b. cyclopentane c. cyclic hexane d. cyclohexane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 53  Section 12.12 Cycloalkanes The structure is known as a : a. cyclicpentane b. cyclopentane c. cyclic hexane d. cyclohexane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 54  Section 12.13 IUPAC Nomenclature for Cycloalkanes Procedures are similar to those for alkanes Ring portion of the cycloalkane molecule serves as a name base – The prefix cyclo- indicates the presence of the ring Numbering conventions are used in locating substituents on the ring ‒ If there is just one ring substituent, it is not necessary to locate it by number Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 55  Section 12.13 IUPAC Nomenclature for Cycloalkanes ‒ When two ring substituents are present, the carbon atoms in the ring are numbered beginning with the substituent of higher alphabetical priority and proceeding in the direction (clockwise or counterclockwise) that gives the other substituent the lower number ‒ When three or more ring substituents are present, ring numbering begins at the substituent that leads to the lowest set of location numbers. When two or more equivalent numbering sets exist, alphabetical priority among substituents determines the set used Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 56  Section 12.13 IUPAC Nomenclature for Cycloalkanes Practice Exercise Assign IUPAC names to each of the following cycloalkanes a. b. c. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 57  Section 12.13 IUPAC Nomenclature for Cycloalkanes Practice Exercise Assign IUPAC names to each of the following cycloalkanes a. b. c. Answers: a. Methylcyclopropane b. 1-Ethyl-4-methylcyclohexane c. 4-Ethyl-1,2 dimethylcyclopentane Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 58  Section 12.13 IUPAC Nomenclature for Cycloalkanes When naming cycloalkanes, the prefix cis- means _____ and trans- means _____. a.On the same side; across from b.Across from; on the same side c.A carbon contains one hydrogen atoms; a carbon contains two hydrogen atoms d.Cis- and trans- prefixes are not used in naming cycloalkanes. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 59  Section 12.13 IUPAC Nomenclature for Cycloalkanes When naming cycloalkanes, the prefix cis- means _____ and trans- means _____. a.On the same side; across from b.Across from; on the same side c.A carbon contains one hydrogen atoms; a carbon contains two hydrogen atoms d.Cis- and trans- prefixes are not used in naming cycloalkanes. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 60  Section 12.14 Isomerism in Cycloalkanes Some substituted cycloalkanes exhibit stereoisomerism – Stereoisomers have the same molecular and structural formulas but different orientations of atoms in space Several forms of stereoisomerism exist – Cis-trans isomers have the same molecular and structural formulas but different spatial orientations of atoms due to the restricted rotation about bonds Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 61  Section 12.14 Isomerism in Cycloalkanes Cis- is a prefix that means “on the same side” – In cis-1,2-dimethylcyclopentane, the two methyl groups are on the same side of the ring Trans- is a prefix that means “across from” – In trans-1,2-dimethylcyclopentane, the two methyl groups are on opposite sides of the ring Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 62  Section 12.15 Sources of Alkanes and Cycloalkanes Natural Gas and Petroleum Unprocessed natural gas contains: – 50 – 90% methane – 1 – 10% ethane – Up to 8% higher alkanes (primarily propane and butanes) Crude petroleum is a complex mixture of acyclic and cyclic hydrocarbons Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 63  Section 12.15 Sources of Alkanes and Cycloalkanes Refining Petroleum Refining is the process of separating crude petroleum into useful fractions by fractional distillation – Fractional distillation separates the various components of petroleum using their boiling points Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 64  Section 12.15 Sources of Alkanes and Cycloalkanes The reason gasoline is so expensive is because: a. It is prepared by complex synthetic procedures developed in the laboratory. b. Drilling for natural gasoline reserves is dangerous and expensive. c. It is obtained from crude oil. d. Large gasoline suppliers want to make huge profits. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 65  Section 12.15 Sources of Alkanes and Cycloalkanes The reason gasoline is so expensive is because: a. It is prepared by complex synthetic procedures developed in the laboratory. b. Drilling for natural gasoline reserves is dangerous and expensive. c. It is obtained from crude oil. d. Large gasoline suppliers want to make huge profits. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 66  Section 12.16 Physical Properties of Alkanes and Cycloalkanes Alkanes and cycloalkanes are insoluble in water – Water is polar Alkanes and cycloalkanes have densities lower than that of water – Densities fall between 0.6 g/mL and 0.8 g/mL The boiling points of continuous-chain alkanes and cycloalkanes increase with an increase in carbon–chain length or ring size Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 67  Section 12.16 Physical Properties of Alkanes and Cycloalkanes Figure 12.11 - Comparison of Boiling Points Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 68  Section 12.16 Physical Properties of Alkanes and Cycloalkanes Alkanes and cycloalkanes are: a. Soluble in water b. Miscible in water c. Partially soluble in water d. Insoluble in water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 69  Section 12.16 Physical Properties of Alkanes and Cycloalkanes Alkanes and cycloalkanes are: a. Soluble in water b. Miscible in water c. Partially soluble in water d. Insoluble in water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 70  Section 12.17 Chemical Properties of Alkanes and Cycloalkanes Combustion Vigorous reaction with oxygen (usually from air) Accompanied by the evolution of heat and light Always an exothermic process Total combustion of alkanes produces carbon dioxide and water – Incomplete/partial combustion results in a mixture of carbon dioxide and carbon monoxide Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 71  Section 12.17 Chemical Properties of Alkanes and Cycloalkanes Halogenation A chemical reaction between a substance and a halogen with halogens – One or more halogen atoms are incorporated into molecules of the substance H H H H Heat or H C C H + Br2 H C C Br + HBr Light H H H H Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 72  Section 12.17 Chemical Properties of Alkanes and Cycloalkanes Halogenation When alkanes and cycloalkanes undergo combustion when sufficient oxygen is available, what two products are produced? a. Carbon and water b. Carbon monoxide and water c. Carbon dioxide and simpler alkanes d. Carbon dioxide and water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 73  Section 12.17 Chemical Properties of Alkanes and Cycloalkanes Halogenation When alkanes and cycloalkanes undergo combustion when sufficient oxygen is available, what two products are produced? a. Carbon and water b. Carbon monoxide and water c. Carbon dioxide and simpler alkanes d. Carbon dioxide and water Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 74  Section 12.18 Nomenclature and Properties of Halogenated Alkanes Halogenated alkanes: Derivatives alkanes in which one or more halogen atoms are present Halogenated cycloalkanes: Cycloalkane derivatives in which one or more hydrogen atoms are present Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 75  Section 12.18 Nomenclature and Properties of Halogenated Alkanes IUPAC Rules for Naming Halogenated Alkanes Halogen atoms are called fluoro-, chloro-, bromo-, and iodo- In a carbon chain containing a halogen and an alkyl substituent: – The two substituents are considered of equal rank in determining the numbering system – The chain is numbered from the end closer to a substituent Alphabetical priority determines the order in which all substituents present are listed Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 76  Section 12.18 Nomenclature and Properties of Halogenated Alkanes Physical Properties Boiling points of halogenated alkanes are higher than those of the corresponding alkane – Carbon-halogen bonds are a primary contributing factor Two general trends related to boiling and melting points – Boiling points and melting points increase as the size of the alkyl group present increases – Boiling points and melting points increase as the size of the halogen atom increases from fluorine to iodine Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 77  Section 12.18 Nomenclature and Properties of Halogenated Alkanes What are chlorofluorocarbons and why are they dangerous? a. They are gasoline additives and produce chlorine and fluorine gas during combustion. b. They are refrigerants and destroy the ozone layer if they escape into the atmosphere. c. They are refrigerants and produce chlorine gas if they escape into the atmosphere. d. They are used to prepare chlorine gas used in chemical warfare. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 78  Section 12.18 Nomenclature and Properties of Halogenated Alkanes What are chlorofluorocarbons and why are they dangerous? a. They are gasoline additives and produce chlorine and fluorine gas during combustion. b. They are refrigerants and destroy the ozone layer if they escape into the atmosphere. c. They are refrigerants and produce chlorine gas if they escape into the atmosphere. d. They are used to prepare chlorine gas used in chemical warfare. Return to TOC Copyright ©2016 Cengage Learning. All Rights Reserved. 79  Chapter 12 What is the name of the following branched alkane? a. 5-methyl-4,6-ethyloctane b. 4,6-ethyl-5-methyloctane c. 4,6-diethyl-5-methyloctane d. 3,5-diethyl-4-methyloctane Copyright ©2016 Cengage Learning. All Rights Reserved. 80  Chapter 12 What is the name of the following branched alkane? a. 5-methyl-4,6-ethyloctane b. 4,6-ethyl-5-methyloctane c. 4,6-diethyl-5-methyloctane d. 3,5-diethyl-4-methyloctane Copyright ©2016 Cengage Learning. All Rights Reserved. 81  Chapter 12 Convert the line-angle structure below to a condensed structural formula. a. b. c. d. Copyright ©2016 Cengage Learning. All Rights Reserved. 82  Chapter 12 Convert the line-angle structure below to a condensed structural formula. a. b. c. d. Copyright ©2016 Cengage Learning. All Rights Reserved. 83