MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Calculate the percentage of 1-chloro-2-methylbutane in the following reaction. 1) A) 23.14% B) 13.88% C) 27.77% D) 35.18% E) 11.56% 2) Which of the following is a chain propagation step in the free radical chlorination of methane? 2) A) Cl + CH3 CH3Cl B) Cl2 2 Cl C) CH4 + Cl CH3 + HCl D) CH3 + CH4 CH4 + CH3 3) How many distinct dichlorination products can result when isobutane is subjected to free radical chlorination? A) 6 B) 4 C) 2 D) 1 E) 3 3) 4) The reaction Br2 + CH3Br CH2Br2 + HBr was carried out. Which of the following mechanism steps is productive, but relatively unlikely to occur? A) Br + Br2 Br2 + Br B) Br + CH3Br HBr + CH2Br C) Br + CH3 CH3Br D) Br + CH2Br CH2Br2 4) 5) Calculate the percentage of 1-chloro-3,4-dimethylheptane formed in the following reaction. 5) A) B) 6.70 C) D) E)

2 6) Identify the most stable radical. 6) A) B) C) D) E) 7) Calculate the percentage of 1-chloro-2-methylbutane in the following reaction. 7) A) 35.18% B) 27.77% C) 13.88% D) 11.56% E) 23.14% 8) Which of the following represents the best preparation of 2-cyclopentenol from cyclopentane? 8) A) 1. Br2, h 2. H2O2 B) 1. NBS, CCl4 2. H2O2 3. Br2, CCl4 4. NaOCH3 C) 1. NBS, CCl4 2. Br2, CCl4 3. NaOH D) 1. Br2, h 2. NaOCH3 3. NBS, CCl4 4. H2O E) 1. NBS, CCl4 2. NaOCH3 3. H2O2 9) If cyclohexane reacts with excess Cl2 at high temperature, how many distinct dichlorocyclohexane products are possible? Include all stereoisomers. A) 6 B) 8 C) 9 D) 5 E) 7 9) 10) Which of the following is the most stable radical? 10) 2

3 11) The reaction Br2 + CH3Br CH2Br2 + HBr was carried out. Which of the following mechanism steps is both productive and relatively likely to occur? A) Br + CH2Br CH2Br2 B) Br + CH3 CH3Br C) Br + CH3Br HBr + CH2Br D) Br + Br2 Br2 + Br 11) 12) When (R)-2-bromobutane reacts with Cl2/hv, which of the following is true? 12) I II A) Only I is formed. B) Only II is formed. C) I and II are formed in equal amounts. D) I and II could never form under these conditions. E) I and II are formed in unequal amounts. 13) Which of the following is not an intermediate or product in the reaction of 13) 3

4 14) What is the major product of the following reaction? 14) 15) Calculate the percentage of 3-chloro-3,4-dimethylheptane formed in the following reaction. 15) A) B) C) D) E) ) What reagent can best be used to convert cyclopentene to 3-bromocyclopentene in a single step? A) NBS, B) Br2, h C) HBr D) HBr with peroxide E) none of the above 16) 17) Rank the free radicals (I-III) shown below in order of decreasing stability (ie, from most stable to least stable). 17) CH2CH2CH(CH3)2 I CH3CH2C(CH3)2 CH3CHCH(CH3)2 II III A) II > I > III B) III > II > I C) II > III > I D) I > III > II E) I > II > III 4

5 18) When butane undergoes free radical bromination, the product mixture contains 98% 2-bromobutane and 2% 1-bromobutane. How many times more susceptible to hydrogen atom abstraction is a secondary hydrogen in butane than is a primary hydrogen? A) 100 B) 50 C) 73.5 D) 1.5 E) ) 19) Which of the halogens below undergoes free radical halogenation with ethane most rapidly? 19) A) fluorine B) bromine C) chlorine D) pyridine E) iodine 20) How many distinct monochlorinated products, including stereoisomers, can result when the alkane below is heated in the presence of Cl2? 20) A) 1 B) 2 C) 3 D) 4 E) 6 21) Which of the following is the rate-determining step for the monobromination of cyclohexane? 21) 22) Which of the following technique(s) can readily distinguish between: 22)? A) NMR B) IR C) MS D) A and B E) A and C 5

6 23) Which of the following is antiaromatic? 23) 24) Which of the following structures is the most important contributor to the resonance hybrid formed when anisole undergoes o-bromination? 24) 6

7 25) What is one of the products of the following reaction? 25) 26) What is the major product of the following reaction? 26) 7

8 27) Identify the best product for the reaction. 27) A) B) C) D) E) 28) The name 2,4,6-tribromobenzene is incorrect. Which of the following is the correct name? 28) A) m,m-dibromobromobenzene B) m,m,m-tribromobenzene C) 3,5-dibromobromobenzene D) tribromobenzene E) 1,3,5-tribromobenzene 8

9 29) What is the name of the following compound? 29) A) p-dichlorobenzene B) 1,4-dichlorobenzene C) phenyldichloride D) A and B E) B and C 30) Identify the major product for the reaction. 30) A) B) C) 9

10 D) E) 31) What is the structure of p-toluidine? 31) 32) Identify the major product(s) for the reaction. 32) A) 10

11 B) C) D) E) 33) What is the best method for the preparation of p-chlorotoluene in high yield? 33) A) start with p-aminotoluene; NaNO2/HCl, 0 C; CuCl B) start with benzene; chlorinate; methylate C) start with benzene; methylate; chlorinate D) start with toluene; chlorinate E) start with chlorobenzene; methylate 11

12 34) Which of the following structures is the most important contributor to the resonance hybrid formed when toluene undergoes para nitration? 34) 35) Give the best product(s) for the reaction. 35) A) B) 12

13 C) D) E) no reaction 36) What is the structure of 3-phenylpentane? 36) 37) Which of the following fails to produce benzoic acid when heated in the presence of acidic sodium dichromate? A) 2-phenylethanol B) 1-phenylethanol C) 2-phenylheptane D) 1-phenylheptanol E) 2-methyl-2-phenylheptane 37) 13

14 38) Which of the following substrates is an electron withdrawing group overall? 38) 39) Identify the best product for the following reaction. 39) A) B) C) D) E) 14

15 40) What is the major product of the following reaction? 40) A) I B) II C) III D) A and B equally E) A and C equally 41) Which of the following compounds reacts most rapidly with HNO3/H2SO4? 41) A) nitrobenzene B) fluorobenzene C) toluene D) benzonitrile E) anisole 42) What is the proper name of the compound below? 42) A) m-butylhydroxybenzene B) o-butylhydroxybenzene C) ethyl phenyl ether D) 1-phenoxyethane E) m-butylphenol 15

16 43) What is the structure of phenol? 43) 44) Identify the best product for the following reaction. 44) A) B) C) D) E) 16

17 45) Which of the following is the first step in the mechanism of bromination? 45) 46) What is the structure of styrene? 46) 17

18 47) Identify the best product for the following reaction. 47) A) B) C) D) E) + LiBr 48) Identify the best product for the following reaction. 48) 18

19 A) B) C) D) E) 49) What is the major organic product of the reaction between benzene and isobutyl chloride in the presence of AlCl3? A) isobutylbenzene B) chlorobenzene C) n-butylbenzene D) tert-butylbenzene E) sec-butylbenzene 49) 19

20 50) Which of the following is most likely to be the first step in the general mechanism for electrophilic substitution reactions? 50) 51) Identify the major product for the following reaction. 51) A) B) C) D) 20

21 E) 52) Which of the following is not a correct statement concerning the Friedel-Crafts acylation of benzene? A) The acylium ion is often produced from an acyl chloride. B) An alkyl group substitutes for a hydrogen. C) The acylium ion is resonance stabilized. D) More than one equivalent of Lewis acid must be used. E) The benzene ring attacks an acylium ion. 52) 53) Name the following compound. 53) A) tert-hexylbenzene B) 2-phenylhexane C) 3-phenylhexane D) sec-hexylbenzene E) isohexylbenzene 21

22 54) Identify the best product for the following reaction. 54) A) B) C) D) E) 55) Which of the following is one of the resonance contributors of the intermediate produced in a Friedel-Crafts alkylation of benzene? 55) 22

23 56) Predict the major organic product of the following reaction. 56) 57) Identify the best product for the following reaction. 57) A) B) C) D) 23

24 E) 58) Which of the following is an aromatic hydrocarbon? 58) 59) Which of the following is the electrophile that attacks the aromatic ring during nitration? 59) A) NO2 + B) HNO3 C) NO2 - D) NO2 E) HNO3-60) Which of the following is aromatic? 60) 24

25 61) What is the major product of the following Friedel-Crafts alkylation? 61) 62) Which of the following is the electrophile that attacks the aromatic ring during sulfonation? 62) A) SO2 + B) HSO4 - C) HSO3 - D) H2SO4 E) HSO3 + 63) Which of the following protons gives an NMR signal with the highest chemical shift value (farthest downfield)? 63) (CH3)2CH O CH2CH2CH A) 1 B) 2 C) 3 D) 4 E) 5 64) What is the ratio of the protons in the following compound? 64) A) 3:2 B) 6:2 C) 3:3:3:2 D) 6:3:2 E) 9:2 65) Which of the following spectroscopic techniques uses the lowest energy of the electromagnetic radiation spectrum? A) NMR B) X-ray C) IR D) visible E) UV 65) 25

26 66) Predict the splitting pattern in the proton coupled 13C NMR spectrum for the following compound. 66) A) A, G = quintet; B = quartet; D, E = triplet; C, F = doublet B) A, B, G = quartet; C, D, E, F = doublet C) A, B, G = triplet; C, D, E, F = singlet D) A, G = triplet; B = doublet; D, E = singlet E) A, G = quartet; B = triplet; D, E = doublet; C, F = singlet 67) How many signals would you expect to see in the 1H NMR spectrum of the following compound? 67) A) 3 B) 2 C) 4 D) 5 E) 1 68) What is the ratio of the protons in the following compound? 68) A) 3:2:1 B) 3:3:2 C) 3:1 D) 6:2:1 E) 3:2 69) Which of the following is used in nuclear magnetic resonance spectroscopy? 69) A) visible B) infrared C) X-ray D) ultraviolet E) radio 26

27 70) How many signals would you expect to see in the 1H NMR spectrum of the following compound? 70) A) 2 B) 7 C) 3 D) 4 E) 8 71) 1H nuclei located near electronegative atoms tend to be relative to 1H nuclei which are not. A) split B) deshielded C) shielded D) resonanced E) none of the above 71) 72) Which of the following protons gives an NMR signal with the lowest chemical shift value (farthest upfield)? 72) F CH2CH2CH2CH2CH2 Br A) 1 B) 2 C) 5 D) 4 E) 3 73) What splitting pattern is observed in the proton NMR spectrum for the indicated hydrogens? 73) A) septet B) singlet C) triplet D) doublet E) quartet 74) If the frequency for flipping a 1H nucleus at an applied field of Tesla is 60 MHz, what would be the applied magnetic field if the frequency is 360 MHz? A) Tesla B) Tesla C) Tesla D) Tesla E) Tesla 74) 75) How many signals would you expect to see in the 1H NMR spectrum of the following compound? 75) A) 6 B) 5 C) 4 D) 3 E) 2 27

28 76) What splitting pattern is observed in the proton NMR spectrum for the indicated hydrogens? 76) CH3OCH2CH2OCH3 A) quartet B) singlet C) doublet D) triplet E) septet 77) Which compound has a 1H NMR spectrum consisting of the following peaks: 0.9 (6H, d), 1.0 (3H, t), 2.2 (2H, q), and 4.0 (1H, septet)? A) (CH3)2CHOCH2CH3 B) (CH3)2CHCH2CO2CH3 C) (CH3)2CHCH2O2CCH3 D) (CH3)2CHCO2CH2CH3 E) (CH3)2CHO2CCH2CH3 77) 78) Give the integration and splitting pattern for each signal in the 1H NMR spectrum. 78) A) a = 2H, triplet; b = 3H, doublet; c = 2H, doublet; d = 1H, singlet B) a = 3H, triplet; b = 2H, sextet; c = 2H, quartet; d = 1H, triplet C) a = 3H, triplet, b = 2H, quintet; c = 2H, triplet; d = 1H, singlet D) a = 2H, triplet; b = 3H, sextet; c = 2H, triplet; d = 2H, doublet E) a = 3H, triplet, b = 2H, doublet; c = 2H, doublet,; d = 1H, singlet 79) What splitting pattern is observed in the proton NMR spectrum for the indicated hydrogens? 79) A) singlet B) doublet C) septet D) triplet E) quartet 80) Predict the integration for each proton in the 1H NMR spectrum. 80) A) a = 5H; b = 5H; c = 7H; d = 7H; e = 7H B) a = 2H; b = 3H; c = 2H; d = 3H; e = 2H C) a = 3H; b = 2H; c = 2H; d = 3H; e = 2H D) a = 3H; b = 2H; c = 2H; d = 2H; e = 3H E) a = 2H; b = 3H; c = 2H; d = 5H; e = 2H 28

29 81) Give the structure of a compound that has a formula of C8H11N and has signals in the 13C NMR spectrum at 25.9 ppm (CH3), 51.1 ppm (CH), ppm (CH), ppm (CH), ppm (CH), and ppm (C). A) 81) B) C) D) E) 29