General, Organic & Biological Chemistry, 5e (Timberlake) Chapter 14 Aldehydes, Ketones, and Chiral Molecules 14.1 Multiple-Choice Questions 1) Which one of the following compounds is an aldehyde? A) OH | CH3 - CH - CH3 B) O CH3 - CH2 - CH C) CH3 - CH = CH - CH2 - CH3 D) CH3 - CH2 - O - CH2 - CH3 E) CH3 - SH Answer: B Objective: 14.1 Global Outcomes: GO2 2) What are the bond angles in a typical carbonyl group? A) 45° B) 90° C) 109.5° D) 120° E) 135° Answer: D Objective: 14.1 Global Outcomes: GO2 3) How many carbonyl-containing isomers does the formula C3H6O have? A) two B) three C) five D) seven E) eight Answer: A Objective: 14.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 4) The compound 2-propanone is also known as A) acetone B) 2-propanone C) dimethyl ketone D) β-propanone E) propylone Answer: A Objective: 14.1 Global Outcomes: GO2 5) The common name for 2-butanone, a readily available solvent, is A) methyl acetone B) methyl ethyl ketone C) β-butanone D) butyl ketone E) butyl ether Answer: B Objective: 14.1 Global Outcomes: GO2 6) Formaldehyde is used industrially to make A) polymers B) insulating materials C) carpeting D) All of the above E) None of the above Answer: D Objective: 14.1 Global Outcomes: GO7 7) Acetone can be produced by the body when a person is A) exercising B) dieting with high protein diets C) ill with a flu D) recovering from surgery E) sleeping Answer: B Objective: 14.1 Global Outcomes: GO7 Copyright © 2016 Pearson Education, Inc 8) Which of the following compounds contains a ketone functional group? A) CH3 | CH3 - C - OH | CH3 B) O CH3 - CH C) CH3 - CH2 - O - CH2 -CH3 D) O CH3 - CH2 - C - CH3 E) CH3 - O - CH | CH3 Answer: D Objective: 14.1 Global Outcomes: GO2 9) What is the IUPAC name for this compound? O CH3 - CH A) methyl aldehyde B) 1-ethanaldehyde C) 1-ethanone D) ethanal E) methanal Answer: D Objective: 14.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 10) What is the IUPAC name for this compound? A) methylcyclohexanone B) 2,5-dimethylcyclohexanone C) 1,4-dimethyl-2-cyclohexanone D) cyclohexyl methyl ketone E) 1,4-dimethyl-3-cyclohexanone Answer: B Objective: 14.1 Global Outcomes: GO2 11) What is the name of this compound? O CH3 - C - CH - CH3 | CH3 A) 2-pentanone B) methyl propyl ketone C) 3-methyl-2-butanone D) 2-methyl-3-butanone E) 2-methyl-3-ketone butane Answer: C Objective: 14.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 12) Three functional groups found in this compound are A) alcohol, aromatic, and ether B) alcohol, aldehyde, and ether C) alcohol, ether, and ketone D) aldehyde, ether, and carboxylic acid E) cycloalkene, alcohol, and carboxylic acid Answer: C Objective: 14.1 Global Outcomes: GO2 13) Which of the following pairs of compounds are isomers? A) CH3CH2CH2OH and CH3OCH3 B) O O CH3CH2 C CH3 and C) CH3 C CH2CH3 OH | CH3CH2 OCH2CH3 and CH3 C CH3 | CH3 D) OH | CH3CH2CHOH and CH3 C HCH2CH3 | CH3 E) O CH3CH2OH Answer: C and H C CH3 Objective: 14.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 14) In all aldehydes except formaldehyde, how many hydrogen atoms is the carbonyl group bonded to? A) one B) two C) three D) four Answer: A Objective: 14.1 Global Outcomes: GO4 15) How many hydrogen atoms is the carbonyl group in a ketone bonded to? A) none B) one C) two D) three E) four Answer: A Objective: 14.1 Global Outcomes: GO4 16) The carbonyl group consists of A) a carbon-oxygen-hydrogen structure B) a carbon-oxygen single bond C) a carbon-oxygen double bond D) a carbon-oxygen triple bond E) a carbon-oxygen-carbon structure Answer: C Objective: 14.1 Global Outcomes: GO2 17) The oxygen atom in a carbonyl group is the carbon atom A) more electronegative than B) less electronegative than C) identical in electronegativity to D) more electropositive than E) more soluble than Answer: A Objective: 14.1 Global Outcomes: GO2 18) How many lone pairs of electrons does the oxygen in a carbonyl group have? A) None, they're all bonded B) one C) two D) three E) four Answer: C Objective: 14.1 Global Outcomes: GO4 Copyright © 2016 Pearson Education, Inc 19) In the IUPAC naming system, a ketone is named by replacing the -e in the corresponding alkane name with A) yne B) ene C) al D) one E) ol Answer: D Objective: 14.1 Global Outcomes: GO2 20) In the IUPAC naming system, an aldehyde is named by replacing the -e of the name of the corresponding alkane with A) yne B) ene C) al D) one E) ol Answer: C Objective: 14.1 Global Outcomes: GO2 21) What is the name of this compound? A) 2-methylbutanone B) 3-methyl-2-butanone C) 2-methyl-3-butanone D) 3-methylbutanone E) pentanone Answer: B Objective: 14.1 Global Outcomes: GO2 22) Formalin is A) another name for formaldehyde B) a plastic C) an aqueous solution of formaldehyde D) an excellent solvent E) a polymer Answer: C Objective: 14.1 Global Outcomes: GO7 Copyright © 2016 Pearson Education, Inc 23) Acetone is a ketone commonly used as a A) preservative B) flavoring agent C) fuel D) solvent E) drain cleaner Answer: D Objective: 14.1 Global Outcomes: GO7 24) The flavoring agent found in vanilla is A) an aldehyde B) a ketone C) a hydrocarbon D) an ester E) a thiol Answer: A Objective: 14.1 Global Outcomes: GO7 25) Aldehydes have higher boiling points than alkanes of similar mass because of A) hydrogen bonding B) dipole-dipole interactions C) ionic bonding D) covalent bonding E) oxygen bonding Answer: B Objective: 14.2 Global Outcomes: GO2 26) The increased boiling point of ketones compared to alkanes and ethers of similar mass is due to A) hydrogen bonding B) dipole-dipole interactions C) a bent chain structure D) resonance E) ionic interactions Answer: B Objective: 14.2 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 27) Low-molecular-weight ketones are soluble in water What is the shortest length of the carbon chain where insolubility becomes important? A) one B) two C) four D) five E) eight Answer: D Objective: 14.2 Global Outcomes: GO2 28) Which of the following would not be water soluble? A) acetone B) propanal C) 3-heptanone D) formaldehyde E) 2-butanone Answer: C Objective: 14.2 Global Outcomes: GO2 29) Which of the following ketones is the most soluble in water? A) O CH3 C CH3 B) O CH3 - CH - C - CH3 | CH3 C) O CH3 - CH2 - C - CH2 - CH2 - CH3 D) O CH3 - C - CH2 - CH2 - CH3 E) O CH3 - CH2 - C - CH2 - CH3 Answer: A Objective: 14.3 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 30) The reduction of 3-pentanone with hydrogen in the presence of a nickel catalyst will yield A) pentane B) 2-pentene C) diethyl alcohol D) 3-pentanol E) pentanaldehyde Answer: D Objective: 14.3 Global Outcomes: GO2 31) The addition of hydrogen to an organic compound or the loss of oxygen is called A) reduction B) oxidation C) dehydration D) halogenation E) hydration Answer: A Objective: 14.3 Global Outcomes: GO2 32) The hydrogenation of 2-methylpropanal gives the product A) 1-butanol B) 2-methylpropanoic acid C) 2-methyl-3-propanol D) 2-methyl-1-propanol E) 2-methyl-2-propanol Answer: D Objective: 14.3 Global Outcomes: GO2 33) The Tollens' test may be used to distinguish A) acids from amines B) esters from acids C) ketones from alcohols D) aldehydes from ketones E) alcohols from alkenes Answer: D Objective: 14.3 Global Outcomes: GO2 34) Benedict's test requires an aldehyde and an adjacent A) saturated carbon B) ketone C) alcohol D) phenyl ring E) acid Answer: C Objective: 14.3 Global Outcomes: GO2 35) Aldehydes and ketones may be reduced to A) acids B) alkanes C) ethers D) alcohols E) esters 10 Copyright © 2016 Pearson Education, Inc Answer: D Objective: 14.3 Global Outcomes: GO2 36) Which of the compounds would give a positive Tollens' test? A) B) C) D) E) Answer: B Objective: 14.3 Global Outcomes: GO2 37) An acetal is formed from two molecules of an alcohol and a(n) A) aldehyde B) ether C) carboxylic acid D) alkyl ether E) ester Answer: A Objective: 14.4 Global Outcomes: GO2 38) How many moles of an alcohol are needed to react with mole of an aldehyde to form a hemiacetal? A) B) 1.5 C) D) E) 3.5 Answer: A Objective: 14.4 Global Outcomes: GO4 11 Copyright © 2016 Pearson Education, Inc 39) How sugars form cyclic hemiacetals? A) Two molecules of a sugar react with one another B) A molecule of sugar reacts with an added alcohol C) A molecule of sugar reacts with itself D) A molecule of sugar reacts with an added aldehyde E) A sugar molecule decomposes Answer: C Objective: 14.4 Global Outcomes: GO2 40) The product of adding two molecules of an alcohol to an aldehyde in the presence of acid is a(n) A) acetal B) ether C) hemiacetal D) hemiether E) hydroxyl group Answer: A Objective: 14.4 Global Outcomes: GO2 12 Copyright © 2016 Pearson Education, Inc 41) Which of these compounds is the hemiacetal that forms when ethanol reacts with propanal? A) OH | CH3 - CH2 C - O - CH2 - CH3 | H B) OH | CH3 - C - O - CH2 - CH3 | H C) O - CH2 – CH2 | CH3 - CH2 - C - O - CH2 - CH3 | H D) O - CH2 - CH3 | CH3 - C - O - CH3 | H E) O - CH2 - CH2 - CH3 | CH3 - C - O - CH2 - CH2 - CH3 | CH2 - CH2 - CH3 Answer: A Objective: 14.4 Global Outcomes: GO2 13 Copyright © 2016 Pearson Education, Inc 42) What is the acetal formed when propanone reacts with two molecules of methanol? A) OH | CH3 - C - CH3 | CH3 B) O - CH3 | CH3 - C - CH3 | O - CH3 C) O - CH3 | CH3 - CO - CH3 | O - CH3 D) CH3 | CH3 - C - O | H CH3 | - C - CH3 | H E) OH | CH3 - C - CH3 | O - CH3 Answer: B Objective: 14.4 Global Outcomes: GO2 43) An enantiomer is A) a stereoisomer that is not a mirror image of another molecule B) a stereoisomer that is a mirror image of another molecule C) a diastereoisomer D) a structural isomer E) a cis-trans isomer Answer: B Objective: 14.5 Global Outcomes: GO2 14 Copyright © 2016 Pearson Education, Inc 44) Chirality occurs when stereoisomers have mirror images that are A) superimposable B) the same C) not superimposable D) not visible to one another E) identical Answer: C Objective: 14.5 Global Outcomes: GO2 45) How many different substituents are required on a carbon atom for it to be chiral? A) one B) two C) three D) four E) Any number from to 4; chiralty does not depend on substitution Answer: D Objective: 14.5 Global Outcomes: GO4 46) Which molecule below has stereoisomers with different biological effects? A) carvone B) nicotine C) LSD D) epinephrine E) All of the above Answer: E Objective: 14.5 Global Outcomes: GO2 47) Chiral drugs consist of only one enantiomer The benefits of using a pure enantiomer, rather than a mixture, include A) higher potency (lower total dose of drug) B) elimination of side effects C) reduced chances of drug interactions D) All of the above E) None of the above Answer: D Objective: 14.5 Global Outcomes: GO2 15 Copyright © 2016 Pearson Education, Inc 48) Achiral compounds are those which A) have no "handedness." B) have different mirror images C) are non-superimposable D) have the same formula but different structures E) are a racemic mixture Answer: A Objective: 14.5 Global Outcomes: GO2 49) Use the structures below to answer: A) A is chiral and B is achiral B) A is achiral and B is chiral C) both A and B are chiral D) both A and B are achiral Answer: D Objective: 14.5 Global Outcomes: GO2 50) Use the structures below to answer: A) A is chiral and B is achiral B) A is achiral and B is chiral C) both A and B are chiral D) both A and B are achiral Answer: A Objective: 14.5 Global Outcomes: GO2 16 Copyright © 2016 Pearson Education, Inc 14.2 True/False Questions 1) All aldehydes have a carbonyl carbon bonded to at least two hydrogens Answer: FALSE Objective: 14.1 Global Outcomes: GO2 2) Many odors from solvents, paint removers, and perfumes are derived from aldehydes or ketones Answer: TRUE Objective: 14.1 Global Outcomes: GO7 3) In a ketone, the carbonyl group is bonded to two other carbon atoms Answer: TRUE Objective: 14.1 Global Outcomes: GO2 4) The carbonyl group consists of a carbon-oxygen single bond, and a second bond to hydrogen Answer: FALSE Objective: 14.1 Global Outcomes: GO2 5) The carbonyl group does not have a dipole Answer: FALSE Objective: 14.1 Global Outcomes: GO2 6) The suffix -one indicates an aldehyde in the IUPAC system of naming Answer: FALSE Objective: 14.1 Global Outcomes: GO2 7) The suffix -al indicates an aldehyde in the IUPAC system of naming Answer: TRUE Objective: 14.1 Global Outcomes: GO2 8) Acetone is a three-carbon aldehyde Answer: FALSE Objective: 14.1 Global Outcomes: GO2 9) Acetone is sometimes produced in pathological conditions such as diabetes Answer: TRUE Objective: 14.1 Global Outcomes: GO7 10) Formaldehyde is used in solution as a germicide and preservative Answer: TRUE Objective: 14.1 Global Outcomes: GO7 11) Excessive exposure to formaldehyde can irritate the eyes and respiratory tract Answer: TRUE Objective: 14.1 Global Outcomes: GO7 17 Copyright © 2016 Pearson Education, Inc 12) A major flavor component of vanilla is an aldehyde Answer: TRUE Objective: 14.1 Global Outcomes: GO2 13) The name of this compound is 3-butanone Answer: FALSE Objective: 14.1 Global Outcomes: GO2 14) The carbonyl group gives aldehydes higher boiling points than alkanes of similar mass Answer: TRUE Objective: 14.2 Global Outcomes: GO2 15) The carbonyl group gives ketones lower boiling points than alkanes of similar mass Answer: FALSE Objective: 14.2 Global Outcomes: GO2 16) Carbonyl compounds having fewer than four carbon atoms are very water soluble Answer: TRUE Objective: 14.2 Global Outcomes: GO2 17) Hexanal would be soluble in water Answer: FALSE Objective: 14.2 Global Outcomes: GO2 18) Propanal is more soluble than pentanal Answer: TRUE Objective: 14.2 Global Outcomes: GO2 19) Acetone would give a positive Tollens' test Answer: FALSE Objective: 14.3 Global Outcomes: GO2 18 Copyright © 2016 Pearson Education, Inc 20) The Tollens' test is used to distinguish between aldehydes and ketones Answer: TRUE Objective: 14.3 Global Outcomes: GO2 21) Primary alcohols are oxidized to ketones Answer: FALSE Objective: 14.3 Global Outcomes: GO2 22) Ketones are reduced to secondary alcohols Answer: TRUE Objective: 14.3 Global Outcomes: GO2 23) Benedict's test can be used to determine whether an α-hydroxyaldehyde functional group is present Answer: TRUE Objective: 14.3 Global Outcomes: GO2 24) An acetal is formed from an aldehyde or ketone and one molecule of alcohol Answer: FALSE Objective: 14.4 Global Outcomes: GO2 25) A hemiacetal has alkoxy and hydroxyl functional groups bonded to the same carbon Answer: TRUE Objective: 14.4 Global Outcomes: GO2 26) Glucose forms a cyclic hemiacetal Answer: TRUE Objective: 14.4 Global Outcomes: GO2 27) This compound is an acetal Answer: TRUE Objective: 14.4 Global Outcomes: GO2 28) Enantiomers are mirror images of each other Answer: TRUE Objective: 14.5 Global Outcomes: GO2 29) A chiral carbon atom can have fewer than four different groups bonded to it Answer: FALSE Objective: 14.5 Global Outcomes: GO2 30) Enantiomers may have very different tastes or smells 19 Copyright © 2016 Pearson Education, Inc Answer: TRUE Objective: 14.5 Global Outcomes: GO2 31) 2-butanol is a chiral molecule Answer: TRUE Objective: 14.5 Global Outcomes: GO2 32) 1-butanol is a chiral molecule Answer: FALSE Objective: 14.5 Global Outcomes: GO2 33) Enantiomers have superimposable mirror images Answer: FALSE Objective: 14.5 Global Outcomes: GO2 34) The biological activity of one of a set of enantiomers may be very different from the biological activity of the other optical isomers Answer: TRUE Objective: 14.5 Global Outcomes: GO2 35) This compound is chiral Answer: TRUE Objective: 14.5 Global Outcomes: GO2 20 Copyright © 2016 Pearson Education, Inc 14.3 Matching Questions Select the correct name for the following A) 3-propanone B) 1-propanone C) diethyl ketone D) propanal 1) O CH3CH2 C CH2CH3 Objective: 14.1 Global Outcomes: GO2 2) O CH3CH2 C H Objective: 14.1 Global Outcomes: GO2 Answers: 1) C 2) D 21 Copyright © 2016 Pearson Education, Inc Match the structural formula with the correct functional group A) aldehyde B) ether C) ketone 3) O CH3CH Objective: 14.1 Global Outcomes: GO2 4) O CH3 C CH2CH3 Objective: 14.1 Global Outcomes: GO2 5) CH3CH2OCH3 Objective: 14.1 Global Outcomes: GO2 6) O CH3CH2 C H Objective: 14.1 Global Outcomes: GO2 Answers: 3) A 4) C 5) B 6) A 22 Copyright © 2016 Pearson Education, Inc Identify the product, if any, that would form in each of the following reactions A) CH3CH3 B) CH3CH2CH3 C) OH | CH3 C HCH3 D) O CH3 C OH E) CH3CH2OH 7) O CH3 C H Objective: 14.3 Global Outcomes: GO2 8) O CH3 C CH3 + H2 Objective: 14.3 Global Outcomes: GO2 9) O CH3 C H + H2 Objective: 14.3 Global Outcomes: GO2 Answers: 7) D 8) C 9) E 23 Copyright © 2016 Pearson Education, Inc ... CH3CH2CH2OH and CH3OCH3 B) O O CH3CH2 C CH3 and C) CH3 C CH2CH3 OH | CH3CH2 OCH2CH3 and CH3 C CH3 | CH3 D) OH | CH3CH2CHOH and CH3 C HCH2CH3 | CH3 E) O CH3CH2OH Answer: C and H C CH3 Objective: 14. 1... A Objective: 14. 5 Global Outcomes: GO2 49) Use the structures below to answer: A) A is chiral and B is achiral B) A is achiral and B is chiral C) both A and B are chiral D) both A and B are achiral... D Objective: 14. 5 Global Outcomes: GO2 50) Use the structures below to answer: A) A is chiral and B is achiral B) A is achiral and B is chiral C) both A and B are chiral D) both A and B are achiral