Test Bank For Organic Chemistry, 11th Edition

Organic Chemistry, 11e (Carey) Chapter 2 Alkanes and Cycloalkanes: Introduction to Hydrocarbons 1) Which of the following statements is not true concerning hydrocarbons? A) Hydrocarbons are compounds that carbon, hydrogen, and oxygen atoms. B) Alkanes, alkenes, and alkynes are examples of aliphatic hydrocarbons. C) Aromatic hydrocarbons are also referred to as arenes. D) Hydrocarbons may contain sigma bonds and/or pi bonds. 2) Alkanes are characterized by the general molecular formula: A) CnH2n−2 B) CnH2n C) CnH2n+2 D) CnH2n+4 3) The carbon-carbon sigma bond in ethane is formed by overlap of which two orbitals? A) 2p-2p B) sp-sp C) sp2-sp2 D) sp3-sp3 4) The sp3 orbitals of carbon in CH4 are formed from the A) three 2p orbitals. B) 2s and two of the 2p orbitals. C) 2s and one of the 2p orbitals. D) 2s and the three 2p orbitals. 5) The geometry of sp3 hybrid orbitals can be described as pointing toward the corners of a A) triangle. B) square. C) tetrahedron. D) square pyramid. 6) What is the Cl-C-Cl bond angle in CCl4? A) 60o B) 90o C) 109.5o D) 120o 1 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 7) What is the estimated C-C-C bond angle in the following model? A) 90o B) 109.5o C) 120o D) 180o 8) The hybridization of carbon atoms 1, 2, and 3 in the following are, respectively, A) sp, sp, and sp2. B) sp, sp, and sp3. C) sp2, sp2, and sp3. D) sp2, sp3, and sp3. 9) The C-C sigma bond in acetylene is formed by the overlap of which two orbitals? A) 2p-2p B) sp-sp C) sp2-sp2 D) sp3-sp3 2 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 10) What are the hybridizations of carbon atoms 2, 3, and 4 shown in the model below? A) sp, sp2, sp2 B) sp, sp2, sp3 C) sp, sp, sp2 D) sp, sp, sp3 11) The shortest and longest carbon-carbon bonds, respectively, in this molecule are A) II and III. B) IV and III. C) I and IV. D) IV and I. 12) The C-C-C bond angle in propyne, shown below, is A) 90°. B) 109.5°. C) 120°. D) 180°. 3 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 13) How many pi bonds are present in the following structure? A) one B) two C) three D) four 14) The carbon-carbon single bond in the following is formed by the overlap of which two orbitals? A) sp-sp B) sp2-sp C) sp2-sp2 D) sp2-sp3 15) How many isomers of C4H9Cl are possible? A) two B) three C) four D) five 16) What is the relationship between the two structures below? A) identical structures B) resonance forms C) constitutional isomers D) different compounds with different compositions 4 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 17) What is the relationship between the following two structures? A) identical structures B) resonance forms C) constitutional isomers D) different compounds with different compositions 18) What is the total number of constitutional isomers with the formula C5H12? A) two B) three C) four D) five 19) How many isomers of C6H14 are possible? A) four B) five C) six D) seven 20) Which of the molecules below is NOT an isomer of formula C6H14? A) A B) B C) C D) D 5 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 21) The common name of the following group is A) n-butyl. B) sec-butyl. C) isobutyl. D) tert-butyl. 22) The tert-butyl group can also be called A) 1,1-dimethylpropyl. B) 1,1-dimethylethyl. C) 2,2-dimethylpropyl. D) 2,2-dimethylethyl. 23) The 1,1-dimethylethyl group, -C(CH3)3, can also be called A) butyl. B) isobutyl. C) sec-butyl. D) tert-butyl. 24) What is the IUPAC name of the following compound? A) 4,4-dimethylpentane B) 1-tert-butylpropane C) 2,2-dimethylpentane D) 1,1,1-trimethylbutane 25) The correct IUPAC name of the following compound is A) 2-ethyl-3,5-dimethylheptane. B) 6-ethyl-5,5-dimethylheptane. C) 3,4,4-trimethyloctane. D) 5,5,6-trimethyloctane. 6 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 26) Which one of the following is 2,2,5-trimethylhexane? A) (CH3)2CHCH2C(CH3)3 B) (CH3)2CHCH2CH2C(CH3)3 C) CH3CH2CH(CH3)C(CH3)3 D) (CH3)2CHCH2CH2CH2C(CH3)3 27) The correct IUPAC name of the following is A) 2,4,7-trimethylnonane. B) 7-ethyl-2,4-dimethyloctane. C) 3,6,8-trimethylnonane. D) 2-ethyl-5,7-dimethyloctane. 28) What is the IUPAC name of the following? A) 5,6-diethylhexane B) 5-ethyl-6-methylheptane C) 2,3-diethylhexane D) 4-ethyl-3-methylheptane 29) Identify the isomer of C6H14 that only has primary and tertiary carbons. A) hexane B) 2,2-dimethylbutane C) 3-methylpentane D) 2,3-dimethylbutane 7 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 30) The systematic name of the following group is A) 5-ethyl-2-methylpentyl. B) 1-ethyl-4-methylpentyl. C) 6-methyl-3-heptyl. D) 2-methyl-5-heptyl. 31) What is the IUPAC name of the following? A) 6-isopropyl-3-methylnonane B) 2-ethyl-5-isopropyloctane C) 6-propyl-3-methylnonane D) 2-ethyl-5-propyloctane 32) What is the IUPAC name of the following structure? A) 3-propylpentane B) 3-ethylhexane C) 2-ethylheptane D) 4-ethylpentane 8 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 33) Which of the following are constitutional isomers? I. 2,3,3-dimethylhexane II. 2,2-diethylpentane III. 3-ethyl-2-methylheptane A) I and II B) I and III C) II and III D) They are all constitutional isomers. 34) Cycloalkanes are characterized by the general molecular formula A) CnH2n−2. B) CnH2n. C) CnH2n+2. D) CnH2n+4. 35) What is the IUPAC name of the following? A) 1-ethyl-4.4-dimethylcyclopentane B) 1-ethyl-3,3-dimethylcyclopentane C) 3-ethyl-1,1-dimethylcyclopentane D) 4-ethyl-1,1-dimethylcyclopentane 36) All the carbons in cyclopentane are A) primary carbons. B) secondary carbons. C) tertiary carbons. D) quaternary carbons. 9 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 37) The correct name of the following compound is A) (1-methylpropyl)cyclohexane. B) (2-methylpropyl)cyclohexane. C) (2,2-dimethylethyl)cyclohexane. D) (2,2-dimethylpropyl)cyclohexane. 38) The correct IUPAC name of the following compound is A) (1-methylhexyl)cyclopentane. B) (1-pentylethyl)cyclopentane. C) 2-cyclopentylheptane. D) 1-cyclopentyl-2-heptane. 39) Cyclohexane is composed of A) methine groups. B) methylene groups. C) methyl groups. D) both methine and methylene groups. 40) Carbon atoms 1, 2, and 3 in the following structure are classified, respectively, as A) tertiary, primary, secondary. B) quaternary, secondary, secondary. C) quaternary, primary, tertiary. D) quaternary, secondary, tertiary. 10 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 41) How many methine groups are there in isopropylcyclopentane? A) one B) two C) three D) four 42) Which of the following describes an atom or group of atoms that has similar chemical properties when it occurs in different compounds? A) hydrocarbon B) functional group C) paraffin D) isomer 43) The boiling point of isobutane (−10.2°C) is lower than n-butane (−0.4°C) because isobutane has A) weaker intermolecular van der Waals forces. B) stronger intermolecular van der Waals forces. C) weaker dipole-dipole attractive forces. D) stronger dipole-dipole attractive forces. 44) Arrange the following hydrocarbons in order of increasing boiling point. I. pentane II. 2,2-dimethylpropane III. 2-methylbutane A) I < II < III B) I < III < II C) II < I < III D) II < III < I 45) Arrange the following isomeric alkanes in order of increasing boiling point. I. n-heptane II. 2,3-dimethylpentane III. 2,2,3-trimethylbutane A) I < II < III B) II < III < I C) III < I < II D) III < II < I 46) Which of the following has the lowest boiling point? A) pentane B) 2,2-dimethylpropane C) 2-methylbutane D) hexane 11 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 47) The smallest straight-chain alkane that is liquid at room temperature and atmospheric pressure is A) propane. B) butane. C) pentane. D) hexane. 48) The lowest-boiling isomer of C7H16 would be A) A. B) B. C) C. D) D. 49) Why can heats of combustion of constitutional isomers of hydrocarbons be used to measure their stabilities? I. Combustion of constitutional isomers gives different final states. II. Combustion of constitutional isomers gives the same final states. III. Constitutional isomers of hydrocarbons have the same potential energies. IV. Constitutional isomers of hydrocarbons have different potential energies. A) only I B) only II C) I and III D) II and IV 50) The heats of combustion (−∆H°) of heptane and 3,3-dimethypentane are 4,817 and 4,809 kJ/mol, respectively. Which statement is true? A) Heptane is 8 kJ/mol more stable then 3,3-dimethylpentane. B) 3,3-Dimethylpentane is 8 kJ/mol more stable than heptane. C) Stabilities cannot be compared since they are not isomers. D) Stabilities cannot be compared since they give different combustion products. 51) How many moles of O2 gas would be consumed in the complete combustion of 0.100 mole of C5H12? A) 0.100 mole O2 B) 0.400 mole O2 C) 0.800 mole O2 D) 1.60 mole O2 12 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education. 52) Which of the following has(have) a higher oxidation state of carbon than the carbon in formaldehyde, H2C=O? I. CH3OH II. HCO2H III. H2CO3 A) I B) III C) II and III D) I, II, and III 53) The oxidation states of carbon range from A) 0 to +2. B) 0 to +4. C) −4 to 0. D) −4 to +4. 54) The reaction of acetylene with hydrogen gas is shown below. Which statements are true concerning the reaction? I. Acetylene is oxidized to ethane. II. Acetylene is reduced to ethane. III. Carbon changes oxidation state from −1 to −3. IV. Hydrogen (from H2) changes oxidation state from 0 to +1. A) I and III B) II and IV C) I, III, and IV D) II, III, and IV 55) How many constitutional isomers of C~6~H~14~ are possible? A) four B) five C) six D) seven 13 Copyright © 2019 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written onsent of McGraw-Hill Education.