1. What is the letter designation given to dumbbell shaped orbitals like the one depicted below?

Transcription

1 1. What is the letter designation given to dumbbell shaped orbitals like the one depicted below? 2. Which of the following does not have an octet of electrons surrounding the central atom? A. B 3 B. C 4 C. N 3 D Predict which bond is the most polar in ethanol, C 3 C 2? 4. Identify the condensed formula of the following structure: Cl 1.(C 3 ) 2 CCClC(C 3 ) 2 2. C 3 C(C C. CClC(C 3 ) 3 3. (C 3 ) 2 CCClC(C 3 ) 3 4. (C 3 ) 3 CCClC(C 3 ) 3 5. ow many C 3 8 constitutional isomers are possible? 6. What best describes the relationship between the following two structures? and 7. What is the formal charge on the carbon atom? C

2 8. Which of the following describes the relationship between the following two structures? 3 C N N and 3 C N N a. identical structures b. resonance forms c. constitutional isomers d. different compounds with different compositions 9. What is the formal charge on the nitrogen atom in the structure below? N C 10. Based on the VSEPR model, which of the following species has(have) a trigonal planar geometry? (A) BCl 3 (B) N 3 (C) N 3 only A A and B A and C A, B, and C 11. Which of the following molecules would you expect to have a dipole moment? (A) C 2 (B) CN (C) CCl 3 B and C only B only C A, B, and C 12. The C C C bond angle in propyne, shown below, is: 3 C C C 90 o o 120 o 180 o 13. ow many pi bonds are present in the following structure? 2 C C C N one two three four five

3 14. Which of the following species have a zero formal charge on its carbon atom? C C C C A B C D A and B B and D C and D A, B, and C 15. Alkanes are characterized by what general molecular formula? 16. Cycloalkanes are characterized by what general molecular formula? 17. The correct IUPAC name of the following compound is: 18. What is the IUPAC name of the following? 19. The C-C sigma bond in acetylene is formed by the overlap of which two orbitals. C C 2p-2p sp-sp sp 2 -sp 2 sp 3 -sp Which of the following are isomers? C 3 C C3 3 3 C C 3 A B C D 21. Identify the isomer of C 6 14 that has only primary and tertiary carbons.

4 22. Carbon atoms 1, 2, and 3 in the following structure are classified, respectively, as: 3 C C 3 1) C 3 2) 3) 23. What is the estimated C-C-C bond angle in the following structure? 24. Identify the conformation of butane shown below: C 3 3 C 25. What is the IUPAC name of the compound shown in the following Newman projection? C 3 3 C 3 C C 3

5 26. What is the dihedral(torsion) angle between the two bromine atoms in the following sawhorse drawing? C 3 C Which statement is correct concerning the relative stabilities of the two conformations, A and B, below: C 3 3 C C 3 C 3 A B A is more stable. B is more stable. A and B are equal in stabilities. A and B are not equal in stability, but the preferred conformation cannot be determined by inspection. 28. Which statement is correct concerning the relative stabilities of the two conformations, A and B, below: C 3 C 3 C 3 3 C C 3 C 3 A B A is more stable. B is more stable. A and B are equal in stabilities. A and B are not equal in stability, but the preferred conformation cannot be determined by inspection.

6 29. Identify the relationship between the following two structures. C 3 C 3 and 3 C C 3 C 3 constitutional isomers stereoisomers different conformations of the same compound idential C Identify the chair conformation of the following compound which is the correct stereoisomer and in its most stable conformation. C(C 3 ) 2 C 3 C(C 3 ) 2 1) 3 C C(C 3 ) 2 3) 3 C C(C 2) 3 ) 2 4) C(C 3 ) 2 C 3 C 3

7 31. The sawhorse drawing of butane below is: C 3 C 3 a gauche conformation the anti conformation the least stable eclipsed conformation the most stable eclipsed conformation 32. What is the IUPAC name of the compound below? C 3 CC 2 C 2 C(C 3 ) Identify the tertiary alcohol(s). C 3 CC 2 C(C 3 ) 2 C 3 C 2 CC(C 3 ) 2 C 3 C 2 C 2 C(C 3 ) 2 A B C 34. Identify the tertiary halide(s). C 3 C 2 3 C 3 C C A B C D 35. What is the hybridization of the oxygen atom in alcohols? 36. What is the nucleophile in the following substitution reaction? (C 3 ) 3 C + (C 3 ) 3 C Which of the following is not a good method to make bromocyclopentane? cyclopentanol plus cyclopentanol plus Na cyclopentanol plus P 3 cyclopentane plus 2 with light

8 38. Arrange the following carbocations in order of their decreasing stabilities (most stable first). C 3 C2 C 3 A B C 39. ow many monochlorination products do you expect in the following reaction? (C 3 ) 2 CC 2 C 3 + Cl 2 heat 40. Which of the following is the most stable radical? 1) C 3 C 2 CC 3 2) C 3 C 2 CC 2 3) C 3 CCC 3 4) C 2 C 2 CC 3 C 3 C 3 C 3 C Which of the following are the chain propagating steps in the free radical chlorination of methane? A. Cl 2 2Cl B. Cl 2 + 2Cl + Cl C. C 4 + Cl C 3 + Cl D. C 4 + C E. C 3 + Cl 2 C 3 Cl + Cl F. C 3 + Cl C 3 Cl 42. What is the product of the following reaction? C 2 C 2 C 2 C 2 + SCl Consider the following reaction (X = Cl or ). light C 3 C 2 C 3 + X 2 C 3 CC 3 + C 3 C 2 C 2 X X Which statement(s) is(are) correct? (A) Statistically the 1-halopropane should be the major isomer. (B) The 2-halopropane to 1-halopropane ratio is largest when X=. (C) The 2-halopropane to 1-halopropane ratio is the largest when X=Cl.

9 44. What are the C C C bond angles in the tert-butyl carbocation? Studies indicate that the methyl radical is trigonal planar. Based on this, which of the following best describes the methyl radical? The carbon is sp 2 hybridized and the unpaired electron occupies an sp 2 orbital. The carbon is sp 2 hybridized and the unpaired electron occupies a 2p orbital. The carbon is sp 3 hybridized and the unpaired electron occupies an sp 3 orbital. The carbon is sp 3 hybridized and the unpaired electron occupies a 2p orbital. 46. Dibromination of isopropylcyclopentane gives a product which can be isolated in good yields. Which of the following would you predict to be this product? C(C 3 ) 2 light CCl 4 C 2 C 2 C(C 3 ) 2 C(C 3 ) 2 1) 2) 3) 4) C(C 3 ) The structure below is a generalized abbreviation for which class of compounds? R 48. Identify the functional group in the boxed area: C 2 C 3 aspirin

10 49. Which of the following mechanistically depicts the protonation of tert-butyl alcohol by hydrogen bromide? 1) (C 3 ) 3 C 2) (C 3 ) 3 C 3) (C 3 ) 3 C 4) (C 3 ) 3 C 50. What is the IUPAC name of the following compound? 51. Which of the following alkenes exhibit E-Z isomerism? A. C 3 C 2 C=CC 2 C 3 C. C 3 C 2 C=C B. (C 3 ) 2 C=CC 3 D. 2 C=CC 2 C(C 3 ) What is the IUPAC name of the following compound? C 2 F C Predict the major product of the following reaction: 2 S 4 C 3 C 2 CC 2 heat C 3 C 3 1) C 3 C 2 C=C 2 3) C 3 C=C(C 3 ) 2 2) C 3 C=CC 2 C 3 4) (C 3 ) 2 CC=C 2

11 54. Which of the following expressions is the experimentally observed rate law for an E2 reaction of an alkyl halide? rate = k[rx] rate = k[rx][base] rate = k[rx] 2 rate = k[base] 55.ow many isomeric alkenes are possible, including stereoisomers, in the following reaction? NaC 2 C 3 C 3 C In the dehydrohalogenation of 2-bromobutane, which conformation below leads directly to the formation of cis-2-butene? C 3 C 3 3 C 3 C 1) 3) 3 C C 3 2) 4) C 3 C Which of the following cannot undergo an E2 reaction? 3 C C 2 3 C C 3 C 2 C 3 A B C 58. When a strong base is used in the elimination reaction of an alkyl halide the mechanism, in general, is: E1 E2 E1 for tertiary halides, E2 for primary and secondary halides E2 for tertiary halides, E1 for primary and secondary halides

12 59. Which of the following sets of conditions most favors the E1 mechanism? When the alkyl halide is tertiary and the base is a weak base. When the alkyl halide is tertiary and the base is a strong base. When the alkyl halide is primary or secondary and the base is a weak base. When the alkyl halide is primary or secondary and the base is a strong base. 60. Which of the following compounds gives a single E2 product on reaction with sodium ethoxide, NaC 2 C 3? 3 C C 3 3 C C 3 3 C C 3 A B C 61. Consider the following reaction. R Na + R + R = -C 2 C 3 or -C(C 3 ) 3 Which statement(s) below is(are) correct? (A) I is the major product based on Zaitsev's rule. (B) The II:I ratio is greater when R = -C 2 C 3 than when R = -C(C 3 ) 3. (C) The II:I ratio is greater when R = -C(C 3 ) 3 than when R = -C 2 C 3. A and B A and C only B only C 62. Which alkene below is thermodynamically the most stable? 1-hexene trans-3-hexene cis-3-hexene 2-methyl-2-pentene I II

13 63. The stereochemical pathway for the hydrogenation of an alkene with a metal catalyst, such as platinum, occurs via: syn addition anti addition Markovnikov addition anti-markovnikov addition 64. What is the major product of the following reaction? 65. What is the intermediate in the following reaction? (C 3 ) 2 C=C 2 + Cl 1) 3 C C C 3 2) 3 C C C 2 3) 3 C C C 2 Cl 4) C 3 C 3 C 3 Cl 3 C C C Which reagent(s) below would work best in converting 2-methyl-2-hexene to 2- methyl-3-hexanol? (1) 2 S 4 (2) 2 50% 2 S 4 / 2 (1) B 3 /TF (2) 2 2, Na 2 / What is(are) the major product(s) of the following reaction? 1) B 2 6, diglyme 2) 2 2, Na 1) 3) C 3 2) 4) both 2 and 3 is 1 is 2 is 3 is 4

14 68. The hydroboration-oxidation reaction can be characterized as the to an alkene. anti-markovnikov syn addition of water anti-markovnikov anti addition of water Markovnikov syn addition of water Markovnikov anti addition of water 69. What is the major product of the following reaction? C 3 C 2 C 2 C C(C 3 ) ,2-dibromo-2-methylhexane 2,2-dibromo-2-methylhexane 2,3-dibromo-2-methylhexane 2,4-dibromo-2-methylhexane 70. Which of the following is least likely to react with an alkene? 1) 3 + 2) Cl 3) C 3 C 2 (ethyl radical) 4) NaC 2 C 3 is 1 is 2 is 3 is Which species below acts as the nucleophile in the acid-catalyzed addition of water to an alkene? 1) 3 + 2) the carbocation 3) - 4) 2 is 1 is 2 is 3 is A compound is treated with ozone followed by zinc in water to give the following three products. Which structure below best fits the data? 3 C C C 3 3 C C

15 73. Draw the intermediate in the bromination of propene? 74. Which of the following correctly depicts the mechanistic first step in the addition of to 2-methylpropene 1) (C 3 ) 2 C=C 2 3) (C 3 ) 2 C=C 2 2) (C 3 ) 2 C=C 2 4) (C 3 ) 2 C=C Which point on the potential energy diagram corresponds to the species below for the reaction of 2-methylpropene with hydrogen chloride? A B C D E δ + C 3 C 3 C C 2 Cl δ 76. Which reaction proceeds by anti addition? C 3 2 / 2 1) 3) C 3 C 3 C 3 C 3 C 2) is 1 is 2 is 3 is 4 C 3 C 3 1) B 3 /TF 2) 2 2, Na 4) C 3 C 3 2 /Pt

16 77. Which point on the potential energy diagram corresponds to the carbocation intermediate, (C 3 ) 3 C +, for the reaction shown below? + (cat.) 2 C=C(C 3 ) (C 3 ) 3 C A C B (C 3 ) 2 C=C / + D E (C 3 ) 3 C Which of the following reactions occurs by a two-step mechanism as opposed to a one-step mechanism? Cl 1) Cl 2) C 3 C 3) NaC 3 C 3 (heat) 4) NaS S 79. Which of the molecules below are chiral? Cl C 3 C 2 CC 2 C 3 C 3 C 2 CCC 3 C 3 C 2 C 2 CC 3 F A B C

17 80. Which of the molecules below are chiral? A B C 81. ow many stereogenic centers are there in the following molecule? C 3 CC 2 CC 2 C 2 CC 3 C 3 C ow many stereogenic centers are there in the following molecule? 3 C C C 3 C Give the configurations, respectively, of the following two molecules. C 3 Cl R and R R and S S and S S and R and 84. What is the IUPAC name of the following compound. 3 C C 2 C Which of the following statements are true. (A) If a molecule has a plane of symmetry it is achiral. (B) If a molecule has a center of symmetry it is achiral. (C) If a molecule has one stereogenic center it is chiral. A and B A and C B and C A, B, and C

18 86. Which of the following undergoes a substitution reaction with sodium cyanide in DMS at the fastest rate? C 3 C 2 F C 3 C 2 Cl C 3 C 2 C 3 C 2 I 87. The rate law for the following reaction is: DMS C 3 C 2 C 2 Cl + NaCN rate = k[c 3 C 2 C 2 Cl] rate = k[c 3 C 2 C 2 Cl][NaCN] rate = k[c 3 C 2 C 2 Cl][NaCN] 2 rate = k[c 3 C 2 C 2 Cl] 2 [NaCN] 88. Which halide ion reacts the fastest with cyclopentyl p-toluenesulfonate in ethanol/water? Ts 1) I - 2) - 3) Cl - 4) F - is 1 is 2 is 3 is Which of the following reacts fastest with methanol by the S N 1 mechanism? C 3 1) C 3 C 2 C 2 C 2 C 2 3) C 3 CC 2 C 3 2) C 3 C 2 CC 2 C 3 4) (C 3 ) 3 CC 2 is 1 is 2 is 3 is A pentacoordinate carbon is a transient species in the mechanism. 91. What is the rate law for the S N 1 mechanism of an alkyl halide with a nucleophile?

19 92. Which of the following does not correctly describe S N 2 reactions of alkyl halides? Tertiary halides react faster than secondary halides. Rate of reaction depends on the concentrations of both the alkyl halide and the nucleophile. Inversion of configuration occurs at the carbon atom bonded to the halide. The transition state species has a pentavalent carbon atom. 93. Identify the substitution product(s) in the following reaction. 3 C C 3 C 3 C 3 C 3 C 3 1) 3 C 3) 3 C C 3 2) C 3 3 C 4) a mixture 1 and What is the rate limiting step in the following reaction? (C 3 ) 3 CCl + 2 (C 3 ) 3 C + Cl 1) (C 3 ) 3 CCl (C 3 ) 3 C + + Cl - 2) (C 3 ) 3 C (C 3 ) 3 C ) (C 3 ) 3 C (C 3 ) 3 C ) Cl - Cl + 2

20 95. The species shown represents the transition state for the: C 2 C 3 2 δ + C δ reaction of 1-propanol with. reaction of 1-bromopropane with -. addition of to 1-propene. addition of to propene with peroxides. 96. Which of the following is the double substitution product of the reaction below? Na 2 S Η Η (meso form) 1) 2) 3) 4) S S S S + enantiomer + enantiomer 97. Identify the mechanistic pathways, respectively, for the products in the following reaction. C 3 Na C 3 C 2 C 2 C 2 C 3 C 2 C=C 2 + C 3 C 2 C 2 C 2 C 3 C What is the major product in the following reaction? K C 3 C 2 1) 3) Et 2) 4)

21 99. Which of the following mechanistic steps is the most likely route for the formation of the cyclic ether shown? NaC 3 Cl C 3 1) Cl 3) Cl 2) 4) 100. In which of the solvents below would the reaction shown take place at the fastest rate? C 3 C 2 C 2 C 2 + NaCN C 3 C 2 C 2 C 2 CN + Na ethanol acetic acid dimethyl sulfoxide water 101. Which of the following describes the C(2) - C(3) sigma bond in the structure below? C C C C sp-sp sp 2 -sp 2 sp 3 -sp 3 2p-2p 102. What is the best base to quantitatively remove a proton from acetylene Arrange the following in order of decreasing base strength (strongest base first). A. C 3 C 2 B. C 3 C 2 C. N 2 D. C C

22 104. Predict the major product(s) in the reactions below. 1) NaN 2 1) NaN 2 C C 2) C 3 2) 1-iodohexane 1-nonyne 2-nonyne cis-2-nonene trans-2-nonene 105. Which of the following alkynes gives a single ketone in the acid-catalyzed hydration of each? 2-decyne 3-decyne 4-decyne 5-decyne 106. Which sequence of reactions works best in synthesizing cis-3-nonene (1) 1-butyne, NaN 2 (2) 1-bromopentane (3) Na, N 3 (1) 1-butyne, NaN 2 (2) 1-bromopentane (3) 2, Lindlar Pd (1) 1-pentyne, NaN 2 (2) 1-bromobutane (3) 2, 2 S 4 /gs 4 (1) 1-pentyne, NaN 2 (2) 1-bromobutane (3) 2 Cl (4) NaN Which of the following is the enol intermediate in the acid-catalyzed addition of water to propyne? C 3 C C 2, 2 S 4 gs 4 C 3 C 3 C 3 1) C C 2) C C 3) C C 4) C 108. What reagent would be used to convert 2-pentyne to trans-2-pentene? C C Which of the following is the correct IUPAC name of the product for the reaction shown below? C 3 C CC 2 C 2 C(C 3 ) 2 Na, N The larger acid dissociation constant, K a, of acetylene as compared to ethylene is primarily attributed to the: greater electronegativity of an sp carbon as compared to an sp 2 carbon. smaller electronegativity of an sp carbon as compared to an sp 2 carbon. acetylide anion being resonance stabilized. the 4 π electrons of the acetylide anion stabilizing the negative charge.

23 111. Rank the following anions in order of increasing base strength. A. C 3 C 2 B. 2 C C C. C C 112. Why can't methanol, C 3, be used as a solvent for sodium amide, NaN 2? Sodium amide is nonpolar and methanol is polar. Sodium amide is polar and methanol is nonpolar. Sodium amide removes the hydroxyl proton from methanol. There would be no ion-dipole attractive forces between the two compounds zonolysis of an alkyne gave the two compounds shown below. What is the IUPAC name of the original alkyne? C 3 C 2 C 2 C 2 and (C 3 ) 3 CC 2 2,2-dimethyl-3-octyne 3,3-dimethyl-4-octyne 2,2-dimethyl-3-heptyne 6,6-dimethyl-3-heptyne 114. Which of the following reagents would be used to convert 2-pentyne to trans-2- pentene? NaN 2, N 3 Na, N 3 2, Lindlar Pd 2, gs 4 / 2 S Which of the following ketones cannot be made by the acid-catalyzed hydration of an alkyne? 1) 2) 3) 4) What is the correct IUPAC name of the following compound? N 2 The total number of resonance forms of the cyclopentadienide anion, C 5 5 -, is:

24 Which of the following are consistent with the requirements for aromaticity? (A) A system with delocalized π electrons in a ring. (B) 4n π electrons in the ring. (C) All the ring atoms must be carbons. (D) (4n + 2) π electrons in the ring. A and B A and D A, B, and C A, C, and D Cyclopentadiene is unusually acidic for a hydrocarbon. Why? The name of the following compound is: N 2 Which hydrogen atom would be most easily extracted by a bromine atoms? C 2 C 2 C 2 C 3 1) 2) 3) 4) Predict the major organic product in the following reaction. Which of the following has the fastest rate of S N 1 hydrolysis in aqueous acetone? C 2 CC 3 C 2 C 2 1) 2) 3) 4)

25 Which of the following is an aromatic hydrocarbon? 1) 2) 3) 4) In which of the following are carbon-carbon bond lengths arranged in the correct order? shortest longest benzene ethylene cyclohexane ethylene cyclohexane benzene cyclohexane benzene ethylene ethylene benzene cyclohexane What is the product from the reaction sequence shown below? The first step is a free radical chlorination. C(C 3 ) 2 NBS, CCl 4 NaEt (1) B 2 6, diglyme benzoyl peroxide, Et heat (2) 2 2, Na Which one of the following is not a resonance form of the benzyl free radical? C 2 C 2 C 2 C 2 1) 2) 3) 4) What is the electrophile in the Friedel-Crafts alkylation reaction below? C(C 3 ) 3 (C 3 ) 3 CCl AlCl 3 Which species below best depicts the electrophile in the Fe 3 -catalyzed bromination of benzene? - 1) 2 2) Fe 4 is 1 is 2 is 3 is 4 δ δ 3) Fe 3 4) Fe 3

26 Which point on the potential energy diagram corresponds to the species shown to the right for the electrophilic nitration of benzene with N 3/2S 4? energy A B C D 2 N δ + δ + 2 rxn coord Rank the following compounds in order of decreasing reactivity to aromatic electrophilic bromination. (A) benzene (B) toluene (C) benzoic acid (D) phenol D>B>A>C D>C>B>A B>A>D>C B>C>D>A