Worksheet for Organometallics with Answers - Copy PDF

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organometallics (Ch. 15) worksheet with answers...

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CHAPTER 15—AN INTRODUCTION TO ORGANOMETALLIC COMPOUNDS MULTIPLE CHOICE 1. What term describes the process whereby an alkyl halide undergoes reaction with magnesium metal to give an alkylmagnesium bromide (Grignard reagent)? a. nucleophilic substitution b. electrophilic addition c. oxidative addition d. reductive elimination ANS: C 2. What is he change in oxidation state of the metal when magnesium reacts with an alkyl bromide to give an alkylmagnesium bromide (Grignard reagent)? a. 0 → +1 b. 0 → +2 c. 0 → −1 d. 0 → −2 ANS: B 3. Which of the following is the best choice of solvent for the formation of phenylmagnesium bromide by the reaction of bromobenzene with magnesium? a. water b. methanol c. diethyl ether d. acetic acid ANS: C 4. Which of the following is the best choice of solvent for the formation of phenyllithium by the reaction of bromobenzene with lithium? a. water b. ethanol c. tetrahydrofuran d. acetic acid ANS: C 5. Which of the following bonds has the most ionic character? a. C−Al b. C−Hg c. C−Mg d. C−Zn ANS: C 6. Which of the following bonds has the most ionic character? a. C−Sn b. C−Cu c. C−Zn d. C−Li

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ANS: D 7. Which of the following compounds is the strongest base? a. CH3CH2MgBr b. CH3CH2OH c. CH3CH2OMgBr d. CH3CH3 ANS: A 8. Which of the following compounds is the strongest base? a. NaOH b. NH3 c. CH3Li d. CH3OH ANS: C 9. Which of the following molecules are deprotonated by ethylmagnesium bromide? a. phenol, PhOH b. propyne, CH3C≡CH c. dimethylamine, (CH3)2NH d. all of these ANS: D 10. Which of the following mechanisms accounts for the acid-base reaction of ethylmagnesum bromide with acetylene to give acetylide anion?

a. b. c. d.

1 2 3 4

ANS: A

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11. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

2-methylbutane 3-methyl-1-butanol 3-methyl-2-butene 3-methyl-2-butanol

ANS: A 12. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

2-pentanol pentane 1-pentene (E)-2-pentene

ANS: B 13. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: B

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14. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: D 15. Which of the following alcohols can be prepared from a Grignard reagent and ethylene oxide?

a. b. c. d.

only 1 only 1 and 2 only 1, 2 and 3 1, 2, 3 and 4

ANS: B 16. Which of the following alcohols can be prepared from a Grignard reagent and ethylene oxide?

a. b. c. d.

only 1 and 2 only 1 and 4 only 1, 2 and 3 only 2 and 4

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ANS: D 17. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

1 2 3 4

ANS: B 18. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

1 2 3 4

ANS: C

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19. Which combination(s) of alkyl bromide and epoxide can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the epoxide?

a. b. c. d.

only 1 only 2 only 1 and 3 only 2 and 4

ANS: B 20. Which combination(s) of alkyl bromide and epoxide can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the epoxide?

a. b. c. d.

only 1 only 2 only 1 and 3 only 2 and 4

ANS: A

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21. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: A 22. What is the major organic product obtained from the following reaction?

a. b. c. d.

(E) 2-iodo-2-butene 1-iodo-2-methylpropene methylcyclopropane (E) 2-butene

ANS: D 23. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: A 24. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

2-methylheptane 3-methylheptane 2-methyloctane 3-methyloctane

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ANS: C 25. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

(E) 6,6-dimethyl-1-hexene (E) 5,5-dimethyl-1-heptene (E) 6,6-dimethyl-1-heptene (E) 6,6-dimethyl-2-heptene

ANS: D 26. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

(Z)-6-methyl-2-heptene (E)-4-methyl-2-pentene 2-methylheptane 3-methylheptane

ANS: C 27. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

2-iodo-7-methyloctane (E)-7-methyl-1-octene (E)-7-methyl-2-octene (E)-7-methyl-3-octene

ANS: D 28. Which of the following is not true regarding the carbon atom of the methylene carbene, H2C: ? a. it is sp2 hybridized b. it has a complete octet of valence electrons c. it has a vacant 2p atomic orbital d. it has a lone pair of electrons in an sp2 molecular orbital ANS: B

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29. What reactive intermediates are involved in the following reaction?

a. b. c. d.

the trichloromethyl anion (Cl3C: −) and dichlorocarbene (Cl2C:) the trichloromethyl cation (Cl3C+) the cyclohexyl carbocation the cyclic chloronium ion derived from cyclohexene

ANS: A 30. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: C 31. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: B

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32. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: C 33. What is the major organic product obtained from the following reaction?

a. b. c. d.

1 2 3 4

ANS: A 34. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

1 2 3 4

ANS: B

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35. What is the major organic product obtained from the following sequence of reactions?

a. b. c. d.

1 2 3 4

ANS: C PROBLEM 1. What is the major organic product obtained from the following sequence of reactions?

ANS:

2. What is the major organic product obtained from the following reaction?

ANS:

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3. What is the major organic product obtained from the following sequence of reactions?

ANS:

4. What is the major organic product obtained from the following reaction?

ANS:

5. What is the major organic product obtained from the following sequence of reactions?

ANS:

6. What is the major organic product obtained from the following reaction?

ANS:

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7. What is the major organic product obtained from the following reaction?

ANS:

8. What is the major organic product obtained from the following sequence of reactions?

ANS:

9. What is the major organic product obtained from the following reaction?

ANS:

10. What is the major organic product obtained from the following sequence of reactions?

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ANS:

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