PCHE 101 Chapter 16 Organic Chemistry PDF

Chapter 16 Organic Chemistry © 2019 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  Questions for Co...

Chapter 16 Organic Chemistry © 2019 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  Questions for Consideration 1. How can we represent organic molecules to illustrate their similarities and differences? 2. What are hydrocarbons, and where do they come from? 3. What are acyclic hydrocarbons, and how do they react? 4. What are cyclic hydrocarbons, and how do they react? 5. How do alcohols and ether differ from the alkanes? 6. How are aldehydes and ketones alike and different? 7. How do carboxylic acids and esters differ from other organic compounds? 8. What is unique about amines? 9. How do we use the IUPAC system to name organic compounds? © 2019 McGraw-Hill Education  Chapter 16 Topics: 1. Representations of Organic Molecules 2. Hydrocarbons 3. Acyclic Hydrocarbons 4. Cyclic Hydrocarbons 5. Alcohols and Ethers 6. Aldehydes and Ketones 7. Carboxylic Acids and Esters 8. Amines 9. Organic Nomenclature © 2019 McGraw-Hill Education  Organic Chemistry Organic chemistry is the study of organic compounds. Organic compounds contain carbon, hydrogen, and sometimes other elements. The term organic relates to the importance of carbon compounds in Aspirin, C9H8O4 living systems. Figure from p. 653 © 2019 McGraw-Hill Education  16.1 Representations of Organic Molecules Carbon can make 4 bonds. Carbon has the ability to bond to other carbon atoms to form long chains or rings of carbon atoms with hydrogen atoms (or other atoms) attached. Carbon can bond to other carbon atoms in single, double, or triple bonds. © 2019 McGraw-Hill Education  Formulas and Structures Using octane as an example: Ball-and-stick model: Molecular formula: C8H18 Structural formula: Figure from p. 656 CH3CH2CH2CH2CH2CH2CH2CH3 Condensed structural formula: CH3(CH2)6CH3 Line structure: Figure from p. 656 Perspective drawing: Figure from p. 659 © 2019 McGraw-Hill Education  Activity: Drawing a Structural Formula/Line Structure 1 Draw a structural formula for this molecule. A structural formula shows the bonds as lines and labels the atoms. The structural formula for aspirin is: Figures from p. 658, Example 16.1 Jump to long description © 2019 McGraw-Hill Education  Activity: Drawing a Structural Formula/Line Structure 2 Omar studied the aspirin molecule with the ball-and- Figure from p. 659, stick model to the right. Practice Draw a line structure for Problem 16.1 this molecule. The line drawing shows only the bonds between carbon atoms and between carbon atoms and functional groups. Only the functional groups are labeled: Jump to long description © 2019 McGraw-Hill Education  Functional Groups Functional group A reactive part of a molecule that undergoes characteristic reactions Often the functional group is an attachment to the carbon-hydrogen chain. For example, the –OH group in ethanol, CH3CH2OH, is the reactive part of an ethanol molecule. Organic compounds are classified by their functional groups. © 2019 McGraw-Hill Education  Functional Groups in Organic Molecules 1 © 2019 McGraw-Hill Education  Functional Groups in Organic Molecules 2 © 2019 McGraw-Hill Education  Activity: Functional Groups Identify the functional group in each of the following molecules: 1. CH3OH alcohol 2. (CH3)2CO ketone 3. CH3CH2CO2H carboxylic acid 4. CH3CH2NH2 amine 5. CH3CH2CHO aldehyde 6. CH3CO2CH2CH3 ester © 2019 McGraw-Hill Education  16.2 Hydrocarbons A carbon compound that contains only carbon and hydrogen Hydrocarbons can form isomers. Two compounds that have the same composition and formula, but with different arrangements of atoms in their molecular structures are called isomers. © 2019 McGraw-Hill Education  Acyclic Hydrocarbons A hydrocarbon molecule that forms an open chain Bonding electrons are localized (confined to two adjacent atoms). Aliphatic hydrocarbons A hydrocarbon with localized bonds 2 kinds of aliphatic hydrocarbons: Saturated Unsaturated © 2019 McGraw-Hill Education  Saturated and Unsaturated Hydrocarbons Saturated hydrocarbon Contains only single bonds between carbon atoms All carbons are bonded to 4 other atoms. Also called alkanes Unsaturated hydrocarbon Contains one or more double or triple bonds between carbon atoms Hydrocarbons with double bonds are called alkenes. Hydrocarbons with triple bonds are called alkynes. © 2019 McGraw-Hill Education  Which is Saturated? Jump to long description © 2019 McGraw-Hill Education  Classification of Hydrocarbons Jump to long description Figure 16.2 © 2019 McGraw-Hill Education  Cyclic Hydrocarbons Form a closed chain or ring of carbon atoms Aromatic compounds A cyclic molecule containing a ring of carbon atoms attached to each other in alternating single and double bonds Electrons represented by the double bonds are delocalized (spread out over the entire ring structure). © 2019 McGraw-Hill Education  Petroleum A primary source of hydrocarbons Major use: energy production Usually found in one of two forms: Natural gas Used mainly for cooking and heating Crude oil Must be refined before it can be used © 2019 McGraw-Hill Education  Refining Crude Oil Involves a few basic steps: Fractional distillation Separation of petroleum into fractions having different ranges of boiling points Results of fractional distillation in Table 16.2 Differences in boiling points due to intermolecular forces between hydrocarbon molecules Catalytic cracking Uses heat and a catalyst to break down the higher-boiling “gas oil” fraction Used to make gasoline © 2019 McGraw-Hill Education  Petroleum Fractions TABLE 16.2 Petroleum Fractions Fraction Boiling Range (°C) Composition Range Uses natural gas < 20 CH4 to C4H10 fuel, petrochemicals petroleum ether 20-60 C5H12, C6H14 solvent ligroin, or naphtha 60-100 C6H14, C7H16 solvent, raw material gasoline 40-220 C4H10 to C13H28, mostly motor fuel C6H14 to C8H18 kerosene 175-325 C8H16 to C14H30 heating fuel and jet fuel gas oil > 275 C12H26 to C18H38 diesel fuel and heating fuel lubricating oils and high: viscous > C18H38 lubrication greases liquids paraffin high: melting point C23H48 to C29H60 wax products 50-60 asphalt or petroleum high: solid residue roofing, paving, fuel, coke reducing agent © 2019 McGraw-Hill Education  16.3 Acyclic Hydrocarbons Three classes: alkanes alkenes alkynes May be straight-chained or branched Alkanes are saturated, alkenes and alkynes are unsaturated © 2019 McGraw-Hill Education  Alkanes Saturated hydrocarbons with the general formula CnH2n+2 Value of n = 1-4, the alkanes are gases under normal conditions Value of n = 5-18, the alkanes are liquids Value of n = 18+, the alkanes are solids Melting points and boiling points increase as the number of carbon atoms increases. Straight-chain alkanes have higher boiling points than branched alkanes. © 2019 McGraw-Hill Education  Boiling Point Trends Jump to long description Figure 16.3 © 2019 McGraw-Hill Education  Boiling Points of Straight-chain Alkanes versus Branched-chain Alkanes Straight-chain alkanes have more surface contact between molecules than branched-chain alkanes, resulting in higher boiling points. Jump to long description Figure 16.4 © 2019 McGraw-Hill Education  Patterns in Alkane Names Table 16.3 has the names of some common alkanes. Can you see the pattern for naming alkanes? TABLE 16.3 Names of Simple Alkanes Alkane Name Formula (CnH2n+2) methane CH4 ethane C2H6 propane C3H8 butane C4H10 pentane C5H12 hexane C6H14 heptane C7H16 octane C8H18 nonane C9H20 decane C10H22 © 2019 McGraw-Hill Education  How to Name Alkanes Alkanes are named with a prefix denoting the number of atoms in the longest chain followed by the ending –ane. Straight-chain (or normal) alkanes have no branches. Branched-chain alkanes are isomers of straight- chain alkane. We must name their branches separately. © 2019 McGraw-Hill Education  Formulas and Names of Some Alkanes Can you see a pattern in how these alkanes are named? Why do two have the same name? Jump to long description © 2019 McGraw-Hill Education  Activity: Names of Alkanes With a Single Branch Give the IUPAC name for isobutane. © 2019 McGraw-Hill Education  Activity Solution: Names of Alkanes With a Single Branch 1 Step 1: The longest continuous carbon chain has 3 carbons, so the name is based on propane. Step 2: No matter how the longest chain is numbered, the branch occurs at carbon 2. Jump to long description © 2019 McGraw-Hill Education  Activity Solution: Names of Alkanes With a Single Branch 2 Step 3: The branch occurring at position 2 is −CH3, or methyl, named for the alkane it is derived from, methane. Step 4: The name is 2-methylpropane. © 2019 McGraw-Hill Education  Alkyl Groups An alkyl group is a group derived from an alkane by removal of 1 hydrogen atom, with a general formula CnH2n+1. The names of alkyl groups are similar to those of the alkanes, except the –ane ending is replaced by –yl. If you have more than one of the same branch, use the prefixes di- or tri- to designate 2 or 3 of the same alkyl group. If you have more than one branch and they are different alkyl groups, then number them and list them in alphabetical order. © 2019 McGraw-Hill Education  Activity: Names of Alkanes with Multiple Branches Name the isomer of C10H22 that has this structure: © 2019 McGraw-Hill Education  Activity Solution: Names of Alkanes with Multiple Branches The longest continuous carbon chain is 7 carbons long. There are 3 methyl groups, 2 at position 2 and 1 at position 5. Hence the name of this compound is: 2,2,5-trimethylheptane © 2019 McGraw-Hill Education  Activity: Structural Formulas from Names of Alkanes The name of another isomer of C8H18 is: 2,2,3-trimethylpentane. Draw its structural formula. © 2019 McGraw-Hill Education  Activity Solution: Structural Formulas from Names of Alkanes 1 The name of another isomer of C8H18 is: 2,2,3-trimethylpentane. Draw its structural formula. Start by drawing the pentane chain, which contains 5 atoms. © 2019 McGraw-Hill Education  Activity Solution: Structural Formulas from Names of Alkanes 2 The name of another isomer of C8H18 is: 2,2,3-trimethylpentane. Draw its structural formula. Of the 3 methyl groups, 2 are attached to the carbon at position 2 and 1 is attached to the carbon at position 3. Therefore the molecule has the following structure: © 2019 McGraw-Hill Education  Reactions of Alkanes Alkanes don’t undergo chemical reactions readily, but supplying heat or light provides the energy needed to get alkanes to react. Alkanes undergo: Catalytic cracking Breaking apart longer hydrocarbon chains to form shorter hydrocarbon molecules Oxidation in exothermic combustion reactions C3H8 + 5O2 → 3CO2 + 4H2O Reaction with halogens light C6H14 + Br2 C6H13Br + HBr © 2019 McGraw-Hill Education  Reaction of hexane with bromine Reaction of hexane with bromine: light C6H14 + Br2 C6H13Br + HBr When exposed to light, brown colored Br2 reacts in solution, it converts to colorless products. Figure 16.5 © 2019 McGraw-Hill Education (both): ©Tom Pantages  Alkenes Alkenes are generally obtained from petroleum by the cracking alkanes, using heat and a catalyst They can react to form polymers, molecules made of many repeating units. © 2019 McGraw-Hill Education  Alkene Structure and Nomenclature Alkenes contain at least one C=C double bond. With just one double bond, the general formula is CnH2n. Alkenes are named with a prefix denoting the number of atoms in the longest chain followed by the ending –ene. Multiple double bonds can occur: H2C=CH-CH=CH2 is named 1,3-butadiene © 2019 McGraw-Hill Education  Formulas and Names of Some Alkenes Can you see a pattern in how these alkenes are named? Jump to long description © 2019 McGraw-Hill Education  Activity: Naming Alkenes Name this compound: © 2019 McGraw-Hill Education  Activity Solution: Naming Alkenes The longest carbon chain that contains the double bond is 4 carbons long, so this molecule is a butene. The chain is numbered starting at the end closest to the functional group (the double bond). The branch is a methyl (derived from methane) and it is attached to position 2. The name of this molecule is: 2-methyl-1-butene © 2019 McGraw-Hill Education  Geometric Isomers Unlike alkanes, in which there is free rotation around a single bond, groups attached to a carbon that has a double bond are fixed in position. To have isomers, two different groups must be attached to each of the carbon atoms in the double bond. When the groups on the double bond are arranged differently in space, the two molecules are cis and trans isomers. © 2019 McGraw-Hill Education  Cis and Trans Isomers The attached groups may be on the same side of the molecule (cis isomer) or on opposite sides (trans isomer). Figure from p. 670 These have different properties. For example, the boiling point of the cis isomer is 4oC, while the boiling point of the trans isomer is 1oC. Jump to long description © 2019 McGraw-Hill Education  Cis and Trans Line Structures We can also differentiate between cis and trans isomers with line structures: Figure from p. 670 Jump to long description © 2019 McGraw-Hill Education  Activity: Cis and Trans Isomers Which of these molecules can have cis and trans isomers? Draw structures for any possible isomers. 1. CH3CH2CH=CH2 2. CH3CH2CH=CHCH2CH3 © 2019 McGraw-Hill Education  Activity Solution: Cis and Trans Isomers 1 Which of these molecules can have cis and trans isomers? Draw structures for any possible isomers. 1. CH3CH2CH=CH2 No. This molecule cannot have cis and trans isomers because two different groups are not attached to each carbon in the double bond. 2. CH3CH2CH=CHCH2CH3 Yes. This molecule can have cis and trans isomers because two different groups are attached to each carbon in the double bond. © 2019 McGraw-Hill Education  Activity Solution: Cis and Trans Isomers 2 b) CH3CH2CH=CHCH2CH3 The two molecules that result from the geometric isomerism are: cis-3-hexene trans-3-hexene © 2019 McGraw-Hill Education  Alkyne Structure and Nomenclature Alkynes contain a C≡C triple bond and have the general formula CnH2n-2. Alkynes are named with a prefix denoting the number of atoms in the longest chain followed by the ending –yne. Alkynes do not have geometric isomers. © 2019 McGraw-Hill Education  Reactions of Alkenes and Alkynes Addition reaction One in which extra atoms or groups are added to a simpler hydrocarbon Alkenes and alkynes typically undergo addition reactions across the double or triple bond. Many of these reactions require a catalyst to occur at an appreciable rate. H2C=CH2 + HBr → CH3CH2Br Polymerization A reaction in which small molecules containing double bonds combine together to form large molecules The smaller, repeating units are called monomers. H2C=CH2 + H2C=CH2 + H2C=CH2 + … → -H2C-CH2-CH2-CH2-CH2-CH2-… © 2019 McGraw-Hill Education  Some products made from polymers Figure 16.8 Figure 16.7 © 2019 McGraw-Hill Education (Figure 16.7): ©Tom Pantages; (Figure 16.8): ©Tony Freeman/PhotoEdit, Inc  Alkenes and alkynes also undergo combustion reactions. 2H-C≡C-H + 3O2 → 4CO2 + 2H2O The reaction of the combustion of acetylene was used to give light to cave explorers before electric lamps became available. Figure 16.6 © 2019 McGraw-Hill Education ©Charles D. Winters/Science Source  Activity: Reactions of Alkenes and Alkynes Write an equation to describe the reaction that would occur between 2-butene and HBr. This is an example of an addition reaction: CH3CH=CHCH3 + HBr → CH3CH2CH(Br)CH3 © 2019 McGraw-Hill Education  16.4 Cyclic Hydrocarbons A cycloalkane contains a carbon ring and is a saturated hydrocarbon with general formula CnH2n. Figure from p. 673 A cycloalkene contains carbon ring and is unsaturated with at Figure from p. 674 least 1 double bond. Jump to long description © 2019 McGraw-Hill Education  Aromatic Hydrocarbons In aromatic hydrocarbons, electrons in the double bonds are spread out (or delocalized) over the entire ring structure. Delocalization of electrons creates extra stability and a less reactive nature known as aromatic character. Aromatic compounds are common in biological systems and in drugs. Figure from p. 674 © 2019 McGraw-Hill Education  Aromatic Hydrocarbons: Benzene Two Lewis structures can be written for benzene, giving rise to resonance: Figure from p. 661 This structure is simplified by using a circle to represent the delocalized double bonds: Figure from p. 661 © 2019 McGraw-Hill Education  Some Formulas and Names of Aromatic Hydrocarbons Can you see a pattern in how these aromatic hydrocarbons are named? © 2019 McGraw-Hill Education  Activity: Naming Aromatic Hydrocarbons Name this aromatic compound. © 2019 McGraw-Hill Education  Activity Solution: Naming Aromatic Hydrocarbons The base ring is benzene, so the molecule is a benzene derivative. Numbering begins at the highest priority side chain. Since all the side chains in this molecule are the same (methyl groups), we can begin at any one of them. Methyl groups (–CH3) exist at positions 1, 3, and 5. Thus, the name is: 1,3,5-trimethylbenzene © 2019 McGraw-Hill Education  Activity: Name Another Aromatic Hydrocarbon Name this aromatic compound. © 2019 McGraw-Hill Education  Activity Solution: Name Another Aromatic Hydrocarbon A benzene ring with an –OH group has the special name phenol. Numbering begins at the –OH, so the Br is at carbon 4. The name is 4-bromophenol Alternatively we would name the compound as a derivative of benzene. We number in alphabetical order, so the carbon attached to the bromo group is carbon 1. The alternative name is 1-bromo-4-hydroxybenzene © 2019 McGraw-Hill Education  Reactions of Aromatic Hydrocarbons Benzene and other aromatic compounds lack the reactivity of the double bond in alkenes. However, with the right catalyst, benzene undergoes substitution reactions. Some functional group replaces one or more hydrogens on the benzene ring. Figure from p. 676 © 2019 McGraw-Hill Education  16.5 Alcohols and Ethers Alcohols Alcohols are characterized by the functional group –OH. The –OH group makes alcohols polar and can participate in hydrogen bonding interactions. Properties of Alcohols Short-chain alcohols are water soluble, but solubility decreases as chain length increases. Alcohols have significantly higher boiling points than alkanes of comparable mass. Figure from p. 676 © 2019 McGraw-Hill Education  Alcohols Can you see a pattern in how these alcohols are named? © 2019 McGraw-Hill Education  Activity: Names of Alcohols Name this alcohol: © 2019 McGraw-Hill Education  Activity Solution: Names of Alcohols The longest chain is 5 carbons long and the carbons are singly bonded to one another, thus this molecule is a pentane. There is a methyl group at position 2 and at position 4. With the alcohol group at position 3, the name pentane changes to pentanol (drop the –e and add –ol). The name of this compound is: 2,4-dimethyl-3-pentanol © 2019 McGraw-Hill Education  Ethers An organic molecule that contains an -O- atom bonded to two carbon atoms. General structure: R─O─R’ The –R notation is used to represent the hydrocarbon portion of the molecule. Ethers are polar molecules, and therefore have higher boiling points than alkanes of comparable mass. Ethers tend to be more volatile than alcohols, with lower boiling points than alcohols of comparable mass. © 2019 McGraw-Hill Education  Naming Ethers Names of ethers include the names of the attached alkyl groups, listed alphabetically, then followed by the word ether. For example: CH3CH2-O-CH2CH3 is named diethyl ether. © 2019 McGraw-Hill Education  16.6 Aldehydes and Ketones Aldehydes contain a C=O (carbonyl) group in which at least one hydrogen atom is attached to the carbon atom General formula: R–CHO Is the oxidation product of an alcohol Two common aldehydes are: Formaldehyde (R = H) Acetaldehyde (R = CH3) Jump to long description © 2019 McGraw-Hill Education  Formaldehyde The aldehyde that is called formaldehyde can be combined with phenol to form polymer resins used as an adhesive in plywood and particle board, as well as in insulating foams. Figure 16.9 © 2019 McGraw-Hill Education ©Jim Birk  Aldehydes are easily oxidized. The Tollens test for identifying aldehydes, silver(I) is reduced to silver metal and the aldehyde is oxidized. Note the silver mirror that has lined this inside of the flask. Figure 16.10 © 2019 McGraw-Hill Education ©Martyn F. Chillmaid/SPL/Science Source  Ketones Ketones resemble aldehydes in that they both have carbonyl groups (C=O). Aldehydes have the C=O at the end of the molecule. Ketones have the C=O somewhere in the middle. Acetone (propanone) is the simplest and most important ketone. Jump to long description © 2019 McGraw-Hill Education  16.7 Carboxylic Acids and Esters The characteristic functional group of a carboxylic acid is a carbon atom double-bonded to an oxygen atom and also bonded to an –OH group. The most common carboxylic acid is acetic acid, also called ethanoic acid, which is found in vinegar. Typically weak acids; reactions involve loss of H+ Jump to long description © 2019 McGraw-Hill Education  Carboxylic Acids and Esters Aspirin contains carboxylic acid and ester functional groups. Jump to long description Figure from p. 681 © 2019 McGraw-Hill Education  Esters Contain a carbon double-bonded to an oxygen and singly bonded to another oxygen which is bonded to another carbon group A compound with the general formula RCO2R’ Most esters are volatile liquids with pleasant odors and flavors. Can be formed by a condensation reaction of a carboxylic acid with an alcohol (requires an acid catalyst): Jump to long description Figure from p. 682 © 2019 McGraw-Hill Education © 2019 McGraw-Hill Education  Names of Esters Jump to long description © 2019 McGraw-Hill Education  Triglycerides The common animal and vegetable oils and fats are esters, mostly based on glycerol (an alcohol). Glycerol reacts with carboxylic acids to form an ester called a triglyceride. Jump to long description Figure from p. 682 © 2019 McGraw-Hill Education  Triglycerides are Esters Triglycerides are esters that form from the reaction of glycerol with high-molar-mass acids are liquid oils or solid fats. Depends on the number of double bonds in the alkyl group of the acid (called a fatty acid) If the fatty acid is saturated (no double bonds), then the triglyceride is solid, or fat. If the fatty acid is highly unsaturated (many double bonds), then the triglyceride is a liquid, or oil. The greater the unsaturation, the more liquid-like the triglyceride. © 2019 McGraw-Hill Education  Saturated and Unsaturated Fatty Acids Jump to long description Figure from p. 683 © 2019 McGraw-Hill Education  Reactions of Triglycerides Hydrogenation to convert oils to fats: C3H5(C17H31CO2)3 + 6H2 → C3H5(C17H35CO2)3 Saponification (to make soaps): Jump to long description Figure from p. 684 © 2019 McGraw-Hill Education  16.8 Amines Derivatives of ammonia, NH3, with one or more hydrogen atoms replaced with organic groups Figure from p. 684 Act as bases in chemical reactions Have a disagreeable fishy smell Jump to long description © 2019 McGraw-Hill Education  Amines Two common amines that interfere with cell functioning are: caffeine nicotine Jump to long description Figure from p. 684 © 2019 McGraw-Hill Education  16.9 Organic Nomenclature A few rules for naming alkanes: 1. Determine the longest continuous carbon chain in the hydrocarbon. The name of this alkane constitutes the parent name. 2. Number the carbon atoms in the parent hydrocarbon from the end nearer a branch, so that the branch will have the lowest possible position number. 3. Branches attached to the parent chain are named as alkyl groups. © 2019 McGraw-Hill Education  Organic Nomenclature A few rules for naming alkanes: 4. The name consists of the position number, a hyphen, the branch name, and the straight-chain name. If there is more than one branch, name them in alphabetical order. If the branches are the same alkyl group, precede the name with a prefix (di-, tri-, etc.) indicating the total number of that alkyl group in the molecule, and separate the position numbers with commas. For cycloalkanes, name the same way as straight- chain alkanes and add the prefix cyclo-. © 2019 McGraw-Hill Education  Naming Alkenes and Alkynes Naming Alkenes Use the alkane root, with the ending -ene replacing –ane. Use numbers to designate the position of the double bond. Number the atoms in the parent chain closest to the double bond (even with branches). Name branches the same way as alkanes. Naming Alkynes Do the same as above, except add the ending –yne to the alkane root. © 2019 McGraw-Hill Education  Naming Aromatic Hydrocarbons Aromatic hydrocarbons Benzene derivatives often have special names, such as toluene, phenol, and aniline, that are retained by the IUPAC nomenclature system. If an aromatic group (such as -C6H5) is a substituent, such as C6H5C≡C-H, then it is named as a phenyl group. © 2019 McGraw-Hill Education  Organic Nomenclature Summary TABLE 16.8 Rules for Naming Organic Compounds with Functional Groups Class of Rules for Naming Compound alcohols The common names of the alcohols consist of the alkyl group name followed by the word alcohol. The IUPAC names use the alkane root and replace the –e ending with –ol. Thus, CH3OH is methyl alcohol or methanol, C2H5OH is ethyl alcohol or ethanol, and C3H7OH is propyl alcohol or propanol. ethers The common names of the ethers consist of the names of the substituted alkyl groups, listed alphabetically, and followed by the word ether, as in diethyl ether, C2H5OC2H5, or ethylmethyl ether, C2H5OCH3. aldehydes Common names use the ending –aldehyde, such as in formaldehyde, HCHO, or acetaldehyde, CH3CHO. IUPAC names use the alkane name with the ending –al, such as in methanal, HCHO, or ethanal, CH3CHO. ketones Common names use the names of the two alkyl groups attached to the C=O group, followed by the word ketone. IUPAC names use the alkane name with the ending –one. The solvent commonly called acetone, (CH3)2C=O, is dimethyl ketone or propanone. carboxylic acids Carboxylic acids often have common names, such as formic acid, HCO2H, and acetic acid, CH3CO2H. The IUPAC names use the alkane name with the ending –oic acid. The two examples are methanoic acid and ethanoic acid, respectively. esters Esters have an alkyl group replacing the acidic hydrogen in a carboxylic acid. They are named in the same way as the carboxylic acids from which they are derived, using an –oate ending. Thus, HCO2CH2CH3 is ethyl methanoate) or ethyl formate), and CH3CO2CH3 is methyl ethanoate (or methyl acetate). amines Amines are commonly named by listing the alkyl groups attached to the nitrogen, followed by the word amine. For example NH2CH2CH3 is ethylamine and NH(CH3)2 is dimethylamine. © 2019 McGraw-Hill Education © 2019 McGraw-Hill Education