OC1ws2 - Ochem practice PDF

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Ochem practice ...

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1. Which of the following statements about alkanes is not true?

A. Alkanes are aliphatic hydrocarbons. B. Alkanes contain only C-C and C-H s bonds. C. Alkanes are acyclic or cyclic. D. Acyclic alkanes have two fewer H atoms than cyclic alkanes with the same number of carbons.

2. What is the molecular formula of an alkane that has twenty-three carbon atoms?

A. C23H46 B. C23H48 C. C23H50 D. C23H44

3. What is the hybridization of a carbon atom in an alkane?

A. sp3 B. sp2 C. sp D. p

4. What is the approximate C-C-C bond angle in propane?

A. 90° B. 109.5° C. 120° D. 180°

5. What is the approximate C-C-C bond angle in propane?

A. 90° B. 109.5° C. 120° D. 180°

6. Which of the following is not another representation for 2-methylbutane?

A. I B. II C. III D. IV

7. Which of the following compounds has only primary and secondary carbon atoms?

A. Pentane B. 2-Methylpentane C. 2,2-Dimethylpentane D. 2,3,3-Trimethylpentane

8. Which of the following compounds has only primary and secondary hydrogen atoms?

A. 2-Methylpentane B. 2,2,3-Trimethylpentane C. 3-Methylpentane D. 2,2-Dimethylpentane

9. What is the parent chain for the following compound?

A. Hexane B. Heptane C. Octane D. Nonane

10. What is the name of the alkyl group that contains two carbons in a straight chain and onecarbon branch?

A. Ethyl B. Propyl C. Isopropyl D. None of these 11. What is the IUPAC name for the following compound?

A. 3,5-Diethyl-6-methylheptane B. 3,5-Diethyl-2-methylheptane

C. 3-Ethyl-5-isopropylheptane D. 5-Ethyl-3-isopropylheptane 12. What is the IUPAC name for the following compound?

A. 5-Ethyl-3,6-dimethylheptane B. 3-Ethyl-2,5-dimethylheptane C. 3-Ethyl-2,5-dimethyloctane D. 5-Ethyl-3,6-dimethyloctane

13. What is the IUPAC name for the following compound?

A. 3-Ethyl-2,7-dimethyl-5-sec-butyldecane B. 5-sec-Butyl-3-ethyl-2,7-dimethyldecane C. 2,7-Dimethyl-3-ethyl-5-sec-butyldecane D. 3-Ethyl-2,7-dimethyl-5-isobutyldecane

14. What is the IUPAC name for the following compound?

A. 1-sec-Butyl-4-isopropyl-2-methylcyclohexane B. 1-Isopropyl-3-methyl-4-sec-butylcyclohexane C. 4-Isopropyl-2-methyl-1-sec-butylcyclohexane D. 1-sec-Butyl-3-isopropyl-2-methylcyclohexane

15. What is the IUPAC name for the following compound?

A. 1-Butylcyclohexane B. Cyclohexanebutane C. 1-Cyclohexylbutane D. Butylcyclohexane

16. What is the IUPAC name for the following compound?

A. 1-Butyl-3-methylcyclohexane

B. 1-sec-Butyl-3-methylcyclohexane C. 1-Methyl-3-sec-butylcyclohexane D. 1-sec-Butyl-3-methylhexane 17. What is the common name of the following alkyl group?

A. Isopropyl B. Isobutyl C. sec-Butyl D. tert-Butyl

18. Rank the following alkanes in order of increasing melting point, putting the alkane with the lowest melting point first.

A. I < III < II B. I < II < III C. II < III < I D. III < II < I

19. Which of the following statements about the conformations of acyclic alkanes is not true?

A. The staggered and eclipsed conformations are equally stable. B. The staggered conformations are more stable than the eclipsed conformations.

C. An energy minimum and maximum occur every 60° as the conformation changes from staggered to eclipsed. D. Conformations that are neither staggered nor eclipsed are intermediate in energy.

20. Which of the following is not a conformer of butane?

A. I B. II C. III D. IV

21. Which of the following are anti conformers?

A. I and II B. II and III C. I and IV D. II and IV

22. Rank the conformers of butane in order of decreasing stability, putting the most stable first.

A.

IV > I > II > III

B.

IV > I > III > II

C.

II > III > I > IV

D.

I > IV > II > III

23. Which of the following is the lowest energy conformer of 2,3-dimethybutane?

A.

I

B.

II

C.

III

D.

IV

24. Which of the following cycloalkanes has the least angle strain? A.

Cyclopropane

B.

Cyclohexane

C.

Cyclopentane

D.

Cycloheptane

25. Which of the following chair conformations represents trans-1,4-dimethylcyclohexane?

A.

I

B.

II

C.

III

D.

IV

26. Which of the following is the most stable conformation of trans-1-isopropyl-3methylcyclohexane?

A.

I

B.

II

C.

III

D.

IV

27. What is the alternate chair conformation of the following compound?

A.

I

B.

II

C.

III

D.

IV

28. Rank the conformers of 1,2,4-trimethylcyclohexane in order of decreasing stability, putting the most stable first.

A.

I > II > III > IV

B.

III > II > IV > I

C.

III > IV > II > I

D.

I > II > IV > III

29. What is the IUPAC name of the following compound?

A.

Pentane

B.

2-Methylpentane

C.

2-Methyl-3-ethylpentane

D.

3-Ethyl-2-methylpentane

30. Which of the following conformation is highest in energy?

A. I B. II C. III D. IV

31. Which of the following alkenes are terminal alkenes?

A.

I and II

B.

II and III

C.

I and IV

D.

I and III

32. Which of the statements about the properties of the carbon-carbon double bond is not true?

A. There is restricted rotation around the carbon-carbon double bond. B. Whenever the two groups on each end of a carbon-carbon double bond are the same, two diastereomers are possible. C. Trans alkenes are generally more stable than cis alkenes. D. The stability of the carbon-carbon double bond increases as the number of substituent groups increases.

33. Calculate the degree of unsaturation for a molecule with molecular formula C8H9N.

A. 2 B. 3 C. 4 D. 5

34. What is the IUPAC name for the following compound?

A.

1-Methylcyclopentene

B.

2-Methyl-1-cyclopentene

C.

1-Methylene-1-methylcyclopentane

D.

1-Methylcyclohexene

35. What is the IUPAC name for the following compound?

A.

5-Methyl-5-hexen-2-ol

B.

6-Methyl-6-hepten-2-ol

C.

6-Hydroxy-2-methylheptene

D.

6-Hydroxy-2-methyl-1-heptene 36. Label each C-C double bond in Kavain, a naturally occurring relaxant, as E or Z.

A.

I = Z and II = Z

B.

I = Z and II = E

C.

I = E and II = E

D.

I = E and II = Z

37. Rank the following isomers in order of increasing boiling point, putting the least first.

A.

I < II < III

B.

I < III < II

C.

II < III < I

D.

II < I < III

38. Which of the following is a terpene?

A.

I

B.

II

C.

III

D.

IV

39. Which of the following statements about alkenes is not true? A.

They are less reactive than alkanes.

B.

They can exist as cis/trans isomers.

C.

The bond angle around the C-C double bond is approximately 120°.

D.

The carbon of the C-C double bond is sp2 hybridized.

40. Rank the following compounds in order of decreasing stability, putting the most stable first.

A.

I > II > III

B.

II > I > III

C.

III > II > I

D.

III > I > II

41. Which of the following alkenes will undergo a carbocation rearrangement when reacting with H2O in the presence of a small amount of H2SO4?

A.

Only I and II

B.

Only I and III

C.

Only II and III

D.

I, II, and III

42. Markovnikov addition of HBr to CH3CH=CH2 involves which of the following? A. B. C. D.

Initial attack by bromide anion (Br-). Initial attack by bromine radical (Br•). Formation of a primary carbocation. Formation of a secondary carbocation.

43. Which of the following alkenes reacts fastest with HCl?

A.

I

B.

II

C.

III

D.

IV

44. Predict the product(s) of the following reaction.

A.

Only I and II

B.

Only I and III

C.

Only II and III

D.

Only III and IV 45. Predict the major product of the following reaction.

A.

I

B.

II

C.

III

D.

IV

46. Predict the major product(s) of the following reaction.

A. Only I and II B. Only II and III C. Only III and IV D. Only I and IV

47. What is the major product obtained from the following reaction?

A.

I

B.

II

C.

III

D.

IV

48. What is (are) the major product(s) obtained from the following reaction?

A.

Only I

B.

Only II

C.

Only III

D.

Only I and II

49. What is the best choice of reagent to accomplish the following transformation?

A. HBr B. Br2, H2O C. Br2 D. H2O2/Br2

50. What type of reactive intermediate is formed in the reaction of an alkene with HI to give an iodoalkane?

A. Carbanion B. Carbocation C. Cyclic bromonium ion D. Radical

51. Rank the carbocation in order of increasing stability, putting the least stable first.

A.

III < I < II

B.

III < II < I

C.

I < II < III

D.

I < III < II 52. Which of the following reactions of alkenes takes place with anti stereochemistry only?

A.

Addition of HBr

B.

Addition of H2O in the presence of H2SO4

C.

Addition of BH3 followed by H2O2/HO-

D.

Addition of Br2

53. What is the starting material in the following reaction?

A.

I

B.

II

C.

III

D.

IV

54. Which of the following statements about hydroboration/oxidation of alkenes is true?

A. In hydroboration, the boron atom bonds to the more substituted carbon. B. Hydroboration occurs with anti addition. C. Oxidation occurs with retention of configuration. D. 9-BBN does not undergo hydroboration in the same manner as BH3.

55. Which alkene reacts fastest with HBr?

A. I B. II C. III D. IV...