Problem-Set Solutions Chapter 14 477

Alcohols, Phenols, and Ethers Chapter 14

Problem-Set Solutions

14.1 a. Oxygen has 6 valence electrons and so forms 2 covalent bonds. b. Hydrogen has 1 valence electron and forms 1 covalent bond to complete its “octet” of 2. c. Carbon has 4 valence electrons and so forms 4 covalent bonds. d. A halogen atom has 7 valence electrons and so forms 1 covalent bond.

14.2 a. incorrect b. correct c. correct d. incorrect

14.3 The generalized formula for an alcohol is R–OH, where R is an alkyl group with a saturated carbon attached to the OH group.

14.4 hydroxyl group

14.5 Alcohols may be viewed as being alkyl derivatives of water in which a hydrogen atom has been replaced by an alkyl group.

14.6 R–OH versus R–H

14.7 To name an alcohol by the IUPAC rules, find the longest carbon chain to which the hydroxyl group is attached, number the chain starting at the end nearest the hydroxyl group, and name and locate any other substituents present. Use the suffix –ol. a. 2-pentanol b. ethanol c. 3-methyl-2-butanol d. 2-ethyl-1-pentanol e. 2-butanol f. 3,3-dimethyl-1-butanol

14.8 a. 3-pentanol b. 2-methyl-3-pentanol c. 4-ethyl-1-heptanol d. 2,3-dimethyl-1-butanol e. 2-methyl-2-butanol f. 4,4,5-trimethyl-3-heptanol

14.9 To name an alcohol by the IUPAC rules, find the longest carbon chain to which the hydroxyl group is attached, number the chain starting at the end nearest the hydroxyl group, and name and locate any other substituents present. Use the suffix –ol. a. 1-hexanol b. 3-hexanol c. 5,6-dimethyl-2-heptanol d. 2-methyl-3-pentanol

14.10 a. 2-heptanol b. 1-butanol c. 3-ethyl-1-hexanol d. 3-methyl-4-heptanol

14.11 In an alcohol name, the number before the parent chain designates the position of the –OH group. The positions of the substituents are numbered relative to the –OH group.

C H 2 C H 3 a . C H 3 C H 2 C H C H 2 C H 3 b . C H 3 C H 2 C C H 2 C H 2 C H 3 O H O H

c . C H 2 C H C H 3 d . C H 3 C H C H 2 C H C H 3

O H C H 3 O H C H 3 O H O H f . H 3 C C C H 3

e . C H 3

14.12 a . C H 3 C H C H 2 C H 2 C H 2 C H 2 C H 3 b . C H 2 C C H 2 C H 2 C H 2 C H 3

O H O H C H 3

d . C H 3 C H C H C H 2 C H 3 c . C H 3 C C H 2 C H 2 C H 2 C H 2 C H 3 O H C H 2 C H 3 C H 3

O H e . C H 2 C H 2 C H C H 3 f . O H

C H C H 3 3

14.13 Common names exist for alcohols with simple alkyl groups. The word alcohol, as a separate word, is placed after the name of the alkyl group.

a . C H 3 C H 2 C H 2 C H 2 C H 2 O H b . C H 3 C H 2 C H 2 O H 1 - p e n t a n o l 1 - p r o p a n o l

c . C H 3 C H C H 2 O H d . C H 3 C H 2 C H O H

C H 3 C H 3 2 - m e t h y l - 1 - p r o p a n o l 2 - b u t a n o l

14.14 a . C H 3 C H 2 C H 2 C H 2 O H b. CH3 CH2 CH2 CH2 CH2 CH2 OH 1 - b u t a n o l 1-hexanol

c . C H 3 C H O H d . C H 3 C O H

C H 3 C H 3 2 - p r o p a n o l 2 - m e t h y l - 2 - p r o p a n o l

14.15 Polyhydroxy alcohols (more than one hydroxyl group) can be named with a slight modification: a compound with two hydroxyl groups is named a diol, one with three hydroxyl groups is a triol. a. 1,2-propanediol b. 1,4-pentanediol c. 1,3-pentanediol d. 3-methyl-1,2,4-butanetriol

14.16 a. 2-methyl-1,3-propanediol b. 1,2-butanediol c. 2,3-pentanediol d. 1,2,3-butanetriol

14.17 In naming cyclic alcohols the carbon to which the –OH group is attached is assigned the number 1. The substituents on the ring are numbered relative to the –OH group. However, the number 1 (designating the –OH group) is not included in the name. a. cyclohexanol b. trans-3-chlorocyclohexanol c. cis-2-methylcyclohexanol d. 1-methylcyclobutanol

14.18 a. trans-2-methylcyclohexanol b. cyclopentanol c. cis-3-bromocyclohexanol d. cis-2-methylcyclopropanol

14.19 In the naming of alcohols with unsaturated carbon chains, the longest chain must contain both the carbon atom to which the hydroxyl group is attached and also the carbon atoms which are unsaturated. The chain is numbered from the end that gives the lowest number to the carbon to which the hydroxyl group is attached. Two endings are needed: one for the double or triple bond and one for the –OH group. Unsaturated alcohols are named as alkenols or alkynols.

a. CH3 CH CH2 CH CH2 b . H C C C H C H 2 C H 3 OH O H

c . C H 3 C H C C H 2 H O C H 2 C H 3 d . C C O H C H 3 H H

14.20 a . H 2 C C H C H C H 2 C H 3 b . C H 2 C H 2 C C H O H O H

H O C H 2 C H 2 H

c . C H 2 C H C H C H 2 d . C C H C H 3 O H C H 3 .

14.21 a . C H 2 C H C H 3 For the incorrect name, the wrong parent chain was chosen. The correct name is 2-methyl-1-butanol. O H C H 2

b . C H 3 C H C H 2 C H 2 For the incorrect name, the parent chain was numbered from the wrong end. The correct name is 1,3-butanediol. O H O H

c . C H 3 C H C H C H 3 For the incorrect name, the parent chain was numbered from the wrong end. The correct name is C H O H 3 3-methyl-2-butanol. When there are two possible ways to number the d. HO OH substituents on a ring, choose the way that gives the lowest possible total number. The correct name is 1,3-cyclopentanediol.

14.22 a . C H 3 C H C H C H 3 b . C H 3 C H 2 C H C H C H 3

O H C H 2 O H O H

C H 3 3 - m e t h y l - 2 - p e n t a n o l 2 , 3 - p e n t a n e d i o l

C H 3 C H 3

c . C H 3 C H 2 C C H 3 d . C H 3 C C H 2 C H 2 C H 3 O H O H 2 - m e t h y l - 2 - b u t a n o l 2 - m e t h y l - 2 - p e n t a n o l

14.23 a. No, this is not a constitutional isomer of 1-hexanol; it has a different molecular formula. (This is 1-pentanol.) b. Yes, this is a constitutional isomer of 1-hexanol; the position of the functional group (OH) has changed. (This is 3-hexanol.) c. Yes, this is a constitutional isomer of 1-hexanol; the carbon-chain arrangement has changed. (This is 4-methyl-2-pentanol.) d. Yes, this is a constitutional isomer of 1-hexanol; the position of the functional group (OH) has changed. (This is the same compound as the one in part b., 3-hexanol.) 14.24 a. no b. yes c. yes d. no

14.25 Since the carbon chain is unbranched, there are four possible positions for the –OH group. 1-heptanol, 2-heptanol, 3-heptanol, and 4-heptanol. 14.26 1-octanol, 2-octanol, 3-octanol, 4-octanol

14.27 For the alcohol 2-methyl-x-pentanol, the possible values of x that will give a correct IUPAC name are x = 1, 2, or 3. If x had a higher value, the alcohol would be numbered from the wrong end of the chain (2-methyl-4-pentanol is an incorrect name for 4-methyl-2-pentanol, and 2-methyl-5-pentanol is an incorrect name for 4-methyl-1-pentanol). 14.28 x = 1, 2, or 3 14.29 a. Absolute alcohol is 100% ethyl alcohol, with all traces of water removed. b. Grain alcohol is ethyl alcohol; ethyl alcohol can be synthesized from grains such as corn, rice, and barley. c. Rubbing alcohol is 70% isopropyl alcohol; because of its high evaporation rate, it is used for alcohol rubs combating high body temperatures. d. Drinking alcohol is ethyl alcohol; it is the alcohol produced by yeast fermentation of sugars, and it is present in all alcoholic beverages. 14.30 a. methanol b. ethanol with toxic agents added to make it undrinkable c. 35% solution of ethanol d. drinking alcohol (ethanol)

14.31 a. Glycerol is a thick liquid that has the consistency of honey. b. Ethanol is often produced by a fermentation process. c. Methanol is used as a race car fuel.

d. Methanol can be industrially produced from CO and H2. 14.32 a. isopropyl alcohol b. ethylene glycol c. ethanol d. glycerol

14.33 Alcohols can form hydrogen bonds with one another (see Figure 14.10). Alkane molecules do not form hydrogen bonds. 14.34 Alcohols can hydrogen-bond to water; alkanes cannot. 14.35 a. 1-Heptanol has a higher boiling point than 1-butanol because boiling point increases as the length of the carbon chain increases. b. 1-Propanol has a higher boiling point than butane; 1-propanol forms hydrogen bonds between molecules. c. 1,2-Ethanediol has a higher boiling point than ethanol; because of increased hydrogen bonding, alcohols with multiple –OH groups have higher boiling points than their monohydroxy counterparts. 14.36 a. 1-octanol b. 1-butanol c. 1,3-propanediol

14.37 a. 1-Butanol is more soluble than butane because alcohol molecules can form hydrogen bonds with water molecules. b. 1-Pentanol is more water-soluble than 1-octanol; as the carbon-chain (nonpolar) increases in length, solubility in water (polar) decreases. c. 1,2-Butanediol is more water-soluble than 1-butanol; increased hydrogen bonding makes an alcohol with two –OH groups more soluble than its counterpart with one –OH group.

14.38 a. 1-butanol b. 1-propanol c. 1,2,3-propanetriol

14.39 a. Three hydrogen bonds can form between ethanol molecules (see Figure 14.10). b. Three hydrogen bonds can form between ethanol molecules and water molecules (see Figure 14.11). c. Three hydrogen bonds can form between methanol molecules (see Figure 14.10). d. Three hydrogen bonds can form between 1-propanol molecules (see Figure 14.10).

14.40 a. 3 b. 3 c. 3 d. 3

14.41 Two general methods of preparing alcohols are: 1) the hydration of alkenes, in which a molecule of water is added to a double bond in the presence of a catalyst (sulfuric acid), and

2) the addition of H2 to a carbon-oxygen double bond (a carbonyl group) in the presence of a catalyst.

a. CH3 CH2 b . C H 3 C H 2 C H 2 OH O H O H O H

c . C H 3 C H 2 C C H 3 d . C H 3 C H 2 C H C H 2 C H 3

14.42 a . C H 3 C H C H 2 C H 3 b . C H 3 C H 2 C H C H 3 c . C H 3 C H 2 O H O H O H

d . C H 3 C H C H C H 2 C H 3 a n d C H 3 C H C H 2 C H C H 3

C H 3 O H C H 3 O H

14.43 Alcohols are classified by the number of carbons bonded to the hydroxyl-bearing carbon atom: in a primary alcohol, the hydroxyl-bearing carbon atom is bonded to one other carbon atom; in a secondary alcohol, it is bonded to two other carbon atoms; and in a tertiary alcohol, it is bonded to three other carbon atoms. a. 2-Pentanol is secondary alcohol. b. Ethanol is a primary alcohol. c. 3-Methyl-2-butanol is a secondary alcohol. d. 2-Ethyl-1-pentanol is a primary alcohol. e. 2-Butanol is a secondary alcohol. f. 3,3-Dimethyl-1-butanol is a primary alcohol.

14.44 a. secondary b. secondary c. primary d. primary e. tertiary f. secondary

14.45 In the dehydration of an alcohol, the components of a water molecule (H and OH) are removed from a single molecule or from two molecules. Sulfuric acid is the catalyst. Notice that in parts a. and c. the starting material is the same, but the temperature differs. The same product is formed at both 140oC as at 180oC.

. b . C H C C H a . C H 2 C H C H 3 3 2 C H 3

. . c . C H 2 C H C H 3 d . C H 3 C H 2 C H 2 O C H 2 C H 2 C H 3 .

. b . C H C C H 14.46 a . C H 3 C H C H 2 O C H 2 C H C H 3 3 2 . C H 3 C H 3 C H 3

. . c . C H 3 C H C H C H 3 d . C H 3 C H C H C H 3

14.47 In the dehydration of an alcohol, the components of a water molecule (H and OH) are removed from a single molecule or from two molecules. Apply Zaitsev’s rule in parts a. and b.: the major product in an intramolecular alcohol dehydration reaction is the alkene that has the greatest number of alkyl groups attached to the carbon atoms of the double bond.

a . C H 3 C H C H C H 3 b . C H 3 C H 2 C H 2 o r C H 3 C H O H

O H C H 3 O H C H 3 . C H C H C H O H c . C H 3 C H 2 O H d . 3 2 .

14.48 a . C H 2 C H C H 2 C H 3 b. CH3 CH2 CH2 CH2

O H C H 3 OH

c . C H 3 O H d . C H 3 C H 2 O H

14.49 Primary and secondary alcohols may be oxidized in the presence of a mild oxidizing agent. A primary alcohol produces an aldehyde that is often further oxidized to a carboxylic acid. A secondary alcohol produces a ketone.

O H O O O O R C H R C H R C O H H 1 o A l c o h o l A l d e h y d e C a r b o x l i c a c i d

O H O O R C R R C R H 2 o A l c o h o l K e t o n e

. . a . C H 3 C H 2 C H C H 3 b . C H 3 C H 2 C H 2 O H . O H

. c . C H 3 C H 2 C H 2 O H . d . C H 2 O H

14.50 a. CH3 CH CH2 OH b . C H 3 C H C H C H 3

CH3 C H 3 O H

c . C H 3 C H C H 2 C H 2 O H d .

C H 3 C H 2 O H

14.51 Alcohols undergo several types of reaction. Parts a., d., and f. of this problem are halogenation reactions in which a halogen atom is substituted for the hydroxyl group. Part c. is the mild oxidation of a secondary alcohol. In part b., a water molecule is removed (dehydration reaction) within the molecule (180oC). Remember to use Zaitsev’s rule. In part e., also a dehydration reaction but at a lower temperature, a water molecule is removed from two alcohol molecules to produce an ether (140oC).

. a . C H C H C H C l 3 2 . 2 b . C H 3

c . C H 3 C C H 2 C H 3 d. CH3 CH2 CH CH2 CH3 Cl

. . e . C H 3 C H 2 O C H 2 C H 3 f . C H 2 C H 2 . C l C l .

. 14.52 a . C H 3 C H 2 C H 2 B r b . C H 3 .

. c . C H 3 C H 2 C H 2 C H 2 O C H 2 C H 2 C H 2 C H 3 .

. d . C H C H C C H C H e . C H C H C H 3 2 2 3 3 2 f . C H 2 C H 2 C l C l

14.53 Polymeric alcohols have structures similar to those of substituted polyethylenes.

C H C H

O H O H n

14.54 C H 2 C H O H n

14.55 In a phenol, the –OH group is attached to a carbon atom that is part of an aromatic ring, as in the first structure. In the second structure, the –OH group is attached to an alkyl group, so it is not a phenol.

14.56 The ring to which the –OH group is attached must be a benzene ring.

14.57 In naming phenols, the parent name is phenol; substituents are numbered beginning with the –OH group and proceeds in the direction that gives the lower number to the next carbon atom bearing a substituent. The –OH group is not specified in the name because it is 1 by definition. a. 3-ethylphenol b. 2-chlorophenol c. o-cresol d. hydroquinone e. 2-bromophenol f. 2-bromo-3-ethylphenol

14.58 a. 4-propylphenol b. catechol c. p-cresol d. 2-bromophenol e. 3-chlorophenol f. 4-chloro-2-isopropylphenol

14.59 The positions of the substituents are relative to the –OH group (carbon 1). Methylphenols are called cresols. Each of the three hydroxyphenols has a different name: resorcinol is the meta-hydroxyphenol. O H O H

C H 2 C H 3 a . b .

C l OH O H Br c. d .

C H 3 Br

. O H O H

H 3 C H 2 C C H 2 C H 3 e . f .

O H O H

14.60 a . b .

B r C H 2 C H 3

O H O H

C H 3 c . d .

O H O H O H O H C l C l e . f .

14.61 An antiseptic kills microorganisms on living tissue; a disinfectant kills microorganisms on inanimate objects.

14.62 An antioxidant is a substance that is more readily oxidized than some other substances; the antioxidant is oxidized first, keeping the other substances from becoming oxidized.

14.63 Phenols are weak acids in water solution, and like other weak acids, they ionize in water to form the hydronium ion and a negative ion (the phenoxide ion).

_ O H O + + H 2 O + H 3 O

14.64 Phenols are less acidic than most inorganic weak acids.

14.65 In an ether, an oxygen atom is bonded to two carbon atoms by single bonds. a. Yes, this is an ether. b. No, this is not an ether; it is an alcohol. c. Yes, this is an ether. d. Yes, this is an ether.

14.66 a. ether and alcohol b. two ethers, one with an alkyl and an aromatic group and the other with two aromatic groups c. phenol and ether d. two ethers, one with two alkyl groups and the other with two aromatic groups

14.67 In the IUPAC system, ethers are named as substituted hydrocarbons. The longest carbon chain is the base name. Change the –yl ending of the other alkyl group to –oxy, and place the alkoxy name, with a locator number, in front of the base chain name. a. 1-methoxypropane b. 1-ethoxypropane c. 2-methoxypropane d. methoxybenzene e. cyclohexoxycyclohexane f. ethoxycyclobutane

14.68 a. ethoxyethane b. 2-methoxypropane c. 2-ethoxybutane d. phenoxybenzene e. propoxycyclohexane f. ethoxybenzene

14.69 The common names for ethers use the form: alkyl alkyl ether or dialkyl ether. Two different alkyl groups are written in alphabetical order. a. methyl propyl ether b. ethyl propyl ether c. isopropyl methyl ether d. methyl phenyl ether e. dicyclohexyl ether f. cyclobutyl ethyl ether

14.70 a. diethyl ether b. isopropyl methyl ether c. ethyl sec-butyl ethers d. diphenyl ether e. cyclohexyl propyl ether f. ethyl phenyl ether

14.71 In the IUPAC system, ethers are named as substituted hydrocarbons. The longest carbon chain is the base name. Change the –yl ending of the other alkyl group to –oxy, and place the alkoxy name, with a locator number, in front of the base chain name. a. 1-methoxypentane b. 1-ethoxy-2-methylpropane c. 2-ethoxybutane d. 2-methoxybutane

14.72 a. 1-ethoxypropane b. 1-methoxy-2-methylpropane c. 1-propoxybutane d. 1-methoxy-1,1-dimethylethane

14.73 The common names for ethers use the form: alkyl alkyl ether or dialkyl ether.

a . C H 3 C H O C H 2 C H 2 C H 3 b . C H 3 C H 2 O C H 3

O C H 3 d . C H 3 C H C H 2 C H 2 C H 3

O C H 2 C H 3 c .

O C H 2 C H 3 C H 3

e . f . C H 3 O C H 2 C C H 3

O C H 3

. 14.74 a . C H 3 C H 2 C H 2 C H 2 O C H 3 b . .

c . O C H 2 C H 2 C H 3 d. CH3 CH2 CH CH2 CH2 CH2 CH3

O CH2 CH2 CH3

O C H 3

e . f . C H 3 C H C H C H 2 C H 2 C H 3 C H O O C H 3 3 C H 3

14.75 Constitutional isomers have the same molecular formulas, but different bonding arrangements

between atoms. Ethyl propyl ether has a molecular formula of C5H12O. a. No, this is not a constitutional isomer of ethyl propyl ether; the molecular formula is

C6H14O. b. No, this is not a constitutional isomer of ethyl propyl ether; the molecular formula is

C6H14O. c. Yes, this is a constitutional isomer of ethyl propyl ether; the molecular formula is

C5H12O, and the name is sec-butyl methyl ether. d. No, this is not a constitutional isomer of ethyl propyl ether; the molecular formula is

C6H14O.

14.76 a. no b. yes c. no d. no

14.77 The easiest way to find the common names for the five ethers that are constitutional isomers of ethyl propyl ether is to draw the isomers and then name them.

O O O butyl methyl ether sec-butyl methyl ether isobutyl methyl ether

O O tert-butyl methyl ether ethyl isopropyl ether

14.78 ethyl propyl ether, ethyl isopropyl ether, sec-butyl methyl ether, tert-butyl methyl ether, isobutyl methyl ether

14.79 Functional group isomers are constitutional isomers that contain different functional groups.

a. CH3 O CH2 CH2 CH3 C H 3 O C H C H 3

C H 3 C H 2 O C H 2 C H 3

b. C H 3 C H 2 C H 2 C H 2 O H C H 3 C H 2 C H O H

C H 3 C H C O H C H 3 C H C H 2 O H 3 C H C H 3 3

14.80 a. C H 3 O C H 2 C H 2 C H 3 C H 3 O C H C H 3

C H 3 CH3 CH2 O CH2 CH3

b. C H 3 C H 2 C H 2 C H 2 O H C H 3 C H 2 C H O H

C H 3 C H C H 2 O H C H 3 C O H

C H 3 C H 3

14.81 The values of x for which x-methoxy-3-methylpentane is a correct IUPAC name are: x = 1, 2, or 3. The names that include x = 4 or 5 would be incorrect because the numbering would be from the wrong end of the carbon chain.

14.82 x = 1, 2, or 3

14.83 There is no hydrogen bonding between molecules of dimethyl ether (disruptive forces are greater than cohesive forces); there is hydrogen bonding between molecules of ethyl alcohol (cohesive forces are of about the same magnitude as disruptive forces).

14.84 Alcohols are more soluble because of hydrogen bonding.

14.85 The two chemical hazards associated with ether use are flammability and peroxide formation.

14.86 a. Ethers are much less reactive than alcohols. b. Ethers are slightly less reactive than alkanes.

14.87 Ether molecules cannot form hydrogen bonds with one another because there are no oxygen- hydrogen bonds in ethers.

14.88 two

14.89 In cyclic ethers, the ether functional group is part of a ring system. a. This is a noncyclic ether; the ether functional group is not included in the ring. b. This is a noncyclic ether; the ether functional group is not included in the ring. c. This is a cyclic ether; the functional group is part of the ring system. d. This is a cyclic ether; the functional group is part of the ring system. e. This is a noncyclic ether; the ether functional group is not included in the ring. f. This is a nonether; it is an alcohol.

14.90 a. noncyclic ether b. noncyclic ether c. cyclic ether d. nonether e. noncyclic ether f. cyclic ether

14.91 A thioalcohol has the general formula R–S–H where R is an alkyl group; an alcohol has the general formula R–O–H.

14.92 R–S–R versus R–O–R

14.93 In the IUPAC system, the names of thiols are similar to those of alcohols except that –ol has been replaced by –thiol.

. a. CH SH b . C H 3 C H C H 3 3 . S H

c . C H 2 C H 2 C H 2 C H 3 d . C H 2 C H 2 C H C H 2 C H 3

S H S H C H 3

f . C H 2 C H 2 e . S H S H S H

14.94 a. CH2 CH2 CH3 b. CH3 CH2 SH SH C H 3

c . C H 2 C H 2 C H C H 2 C H 3 d . C H 3 C H 2 C C H 2 C H 3 S H S H S H

S H C H 3 f . C H C C H C H C H C H e . C H 3 2 2 2 2 3

S H C H 3

14.95 In writing common names for thiols, the name of the alkyl group (as a separate word) precedes the word mercaptan. The structures of thiols are similar to those of alcohols, except the oxygen atom is replaced by a sulfur atom. a. methyl mercaptan b. propyl mercaptan c. sec-butyl mercaptan d. isobutyl mercaptan

14.96 a. ethyl mercaptan b. isopropyl mercaptan c. butyl mercaptan d. tert-butyl mercaptan

14.97 The oxidation of an alcohol produces aldehydes (which may be further oxidized to carboxylic acids) and ketones; the oxidation of a thiol produces disulfides.

14.98 a. CH3–CH2–S–S–CH2–CH3 b. CH3–CH2–SH

14.99 In the IUPAC system, the names of thiols are similar to those of alcohols except that –ol has been replaced by –thiol. In writing common names for thiols, the name of the alkyl group (as a separate word) precedes the word mercaptan. a. methylthioethane, ethyl methyl sulfide b. 2-methylthiopropane, isopropyl methyl sulfide c. methylthiocyclohexane, cyclohexyl methyl sulfide d. cyclohexylthiocyclohexane, dicyclohexyl sulfide e. 3-(methylthio)-1-propene, allyl methyl sulfide f. 2-methylthiobutane, sec-butyl methyl sulfide

14.100 a. ethylthioethane; diethyl sulfide b. 2-ethylthiopropane; ethyl isopropyl sulfide c. methylthiocyclopentane; cyclopentyl methyl sulfide d. cyclopentylthiocyclohexane; cyclohexyl cyclopentyl sulfide e. 1-(ethylthio)-2-propene; allyl ethyl sulfide f. 2-methylthiopropane; isopropyl methyl sulfide

14.101 To name an alcohol by the IUPAC rules, find the longest carbon chain to which the hydroxyl group is attached, number the chain starting at the end nearest the hydroxyl group, and name and locate any other substituents present. Use the suffix –ol. Ethers are named as substituted hydrocarbons. The longest carbon chain is the base name. Change the –yl ending of the other alkyl group to –oxy, and place the alkoxy name, with a locator number, in front of the base chain name. a. 2-hexanol b. 3-pentanol c. 3-phenoxy-1-propene d. 2-methyl-1-propanol e. 2-methyl-2-propanol f. ethoxyethane

14.102 C H 2 C H 2 C H 2 C H 2 C H 3 CH3 CH CH2 CH2 CH3 O H OH

CH3 CH2 CH CH2 CH3 C H 2 C H C H 2 C H 3

OH O H C H 3

C H 3 C H 2 C H 2 C H C H 3 C H 3 C C H 2 C H 3 O H C H 3 O H

C H 3 C H 3 C H C H C H 3 C H 2 C C H 3 O H C H 3 O H C H 3

C H 3 C H 2 C H 2 C H 2 O C H 3 C H 3 C H C H 2 O C H 3

C H 3 C H 2 C H O C H 3 C H 3

C H 3 C H 3 C O C H 3

C H 3 C H 2 C H 2 O C H 2 C H 3 C H 3 C H O C H 2 C H 3

14.103 The dehydration of 1-pentanol yields only 1-pentene. Dehydration of 2-pentanol would yield a mixture of alkenes, and the dehydration of 3-pentanol would yield 2-pentene.

14.104 CH3–O–CH3; CH3–CH2–CH2–O–CH2–CH2–CH3; and CH3–O–CH2–CH2–CH3

14.105 a. This is a disulfide; two sulfur atoms are bonded together, and each is bonded to a carbon atom (R–S–S–R). b. This is a thiol (thioalcohol); a sulfur atom is bonded to a carbon atom and to a hydrogen atom (R–SH). c. This is an alcohol; the general formula is R–OH. d. This a peroxide (R–O–O–R). e. This is both an alcohol and a thiol (thioalcohol). f. This is both an ether and a sulfide (thioether).

14.106 a. 1,2-ethanedithiol b. 3-methoxy-1-propanol c. 1-propanol d. 1,2-dimethoxyethane e. methylthioethane f. 1-ethylthio-2-methoxyethane

14.107 The correct IUPAC name is d. 3-methyl-2-butanol.

14.108 c

14.109 The correct answer is b. The organic product formed by the oxidation of a secondary alcohol is a ketone.

14.110 c

14.111 Answer b. is incorrect. Alcohol solubility in water increases (rather than decreases) as the number of –OH groups present increases.

14.112 a

14.113 The correct answer is a. Simple ethers may be viewed as derivatives of water in which both hydrogen atoms have been replaced with alkyl groups.

14.114 d

14.115 Answer a. is correct. A characteristic property of thiols is extremely strong odors.

14.116 d