Choose the single best answer for each of the following questions.

1. Which of the following would you expect to be aromatic?

A) I
B) II
C) III
D) IV
E) None of these

2. Which of the following compounds would be the most stable?

A) I
B) II
C) III
D) IV
E) They are all of equal stability

3. What would be the product of the following reaction?

A) I
B) II
C) III
D) IV
E) All of these

4. Consider the molecular orbital model of benzene. In the ground state how many molecular orbitals are filled with electrons?
A) 1
B) 2
C) 3
D) 4
E) 5

5. Which diene would be least reactive toward Diels-Alder addition of maleic anhydride?

A) I
B) II
C) III
D) IV
E) V

6. Select the structure of the conjugated diene.

A) I
B) II
C) III
D) IV
E) V

7. What product(s) would you expect from the following substitution reaction of ¹⁴C-labelled propene?

	N-bromosuccinimide
14CH2=CH-CH3	---------------------------->
	ROOR, CCl4

A) ¹⁴CH₂=CH-CH₂Br alone
B) ¹⁴CH₂=CH-CH₂Br and CH₂=CH-¹⁴CH₂Br in equal amounts
C) CH₂=CH-¹⁴CH₂Br alone
D) More ¹⁴CH₂=CHCH₂Br but a little CH₂=CH-¹⁴CH₂Br
E) More CH₂=CH¹⁴CH₂Br but a little ¹⁴CH₂=CHCH₂Br

8. Considering both configurational and conformational factors, select the most stable form of 2,4-hexadiene.

A) I
B) II
C) III
D) IV
E) V

9. Which of the following dienes is a cumulated diene?
A) CH₂=CHCH₂CH₂CH=CH₂
B) CH₂=CHCH=CHCH₂CH₃
C) CH₃CH=C=CHCH₂CH₃
D) CH₃CH=CHCH=CHCH₃
E) CH₃CH=CHCH₂CH=CH₂

10. Which carbocation would be most stable?

A) I
B) II
C) III
D) IV
E) V

11. Which is an untrue statement concerning the Diels-Alder reaction?
A) The reaction is a syn addition.
B) The diene must be in the s-cis conformation to react.
C) Most Diels-Alder reactions are reversible.
D) Generally, the adduct formed most rapidly is the exo product.
E) Depending on the nature of the dienophile, both electron-releasing and electron-withdrawing groups in the diene can favor adduct formation.

12. Which of the following is NOT true of benzene?
A) Benzene tends to undergo substitution rather than addition reactions, even though it has a high index of hydrogen deficiency.
B) All of the hydrogen atoms of benzene are equivalent.
C) The carbon-carbon bonds of benzene are alternately short and long around the ring.
D) Only one o-dichlorobenzene has ever been found.
E) Benzene is more stable than the hypothetical compound 1,3,5- cyclohexatriene.

13. Which dibromobenzene can, in theory, yield three mononitro derivatives?
A) o-Dibromobenzene
B) m-Dibromobenzene
C) p-Dibromobenzene
D) All of these
E) None of these

14. Cyclopentadiene is unusually acidic for a hydrocarbon. An explanation for this is the following statement.
A) The carbon atoms of cyclopentadiene are all sp2-hybridized.
B) Cyclopentadiene is aromatic.
C) Removal of a proton from cyclopentadiene yields an aromatic anion.
D) Removal of a hydrogen atom from cyclopentadiene yields a highly stable free radical.
E) Removal of a hydride ion from cyclopentadiene produces an aromatic cation.

15. Which compound would you NOT expect to be aromatic?

A) I
B) II
C) III
D) IV
E) V

16. Which of the following reagents does not generate an electrophile?
A) HONO₂ / H₂SO₄
B) KMnO₄ / KOH
C) Br₂ / FeBr₃
D) CH₃CH₂Cl / AlCl₃
E) None of these

17. In which case is the indicated unshared pair of electrons NOT a contributor to the p-aromatic system?

A) I
B) II
C) III
D) IV
E) none of these

18. Which of the compounds listed below would you expect to give the greatest amount of meta-product when subjected to ring nitration?

A) I
B) II
C) III
D) IV
E) V

19. The major product(s), B, of the following reaction,

would be:
A) I
B) II
C) III
D) Equal amounts of I and II
E) Equal amounts of I, II and III

20. The major product(s), C, of the following reaction,

would be:
A) I
B) II
C) III
D) Equal amounts of I and II
E) Equal amounts of I, II and III

21. Which of the following structures does not contribute to the resonance hybrid of the intermediate formed when bromobenzene undergoes para-chlorination?

A) I
B) II
C) III
D) IV
E) All of these contribute

22. The product, F, of the following reaction sequence,

would be:

A) I
B) II
C) III
D) IV
E) V

23. Toluene is the name commonly assigned to:
A) Hydroxybenzene
B) Aminobenzene
C) Methylbenzene
D) Ethylbenzene
E) Methoxybenzene

24. Which of the following reactions could be used to synthesize tert-butylbenzene?

A) I
B) II
C) III
D) all of the above
E) none of the above

25. Which of these liquids would be unsuitable as an inert solvent for a Friedel-Crafts reaction?
A) Chlorobenzene
B) Nitrobenzene
C) Acetophenone
D) (Trifluoromethyl)benzene
E) All could be used.

26. Starting with benzene, the best method for preparing p-nitrobenzoic acid is:
A) HNO₃/H₂SO₄; then CH₃Cl/AlCl₃; then separation of isomers; then KMnO₄/-OH, followed by H₃O+.
B) CH₃Cl/AlCl₃; then HNO₃/H₂SO₄; then separation of isomers; then KMnO₄/-OH, followed by H₃O+.
C) CH₃Cl/AlCl₃; then KMnO₄/-OH, followed by H₃O+; then HNO₃/H₂SO₄.
D) HNO₃/H₂SO₄; then KMnO₄/-OH, followed by H₃O+; then CH₃Cl/AlCl₃.
E) HNO₃/H2SO₄; then CO₂, followed by H₃O+.

27. Which of the following reactions would produce p-chloronitrobenzene?
A) (1) Cl₂, Fe; (2) HONO₂/H₂SO₄
B) (1) Cl₂, FeCl₃; (2) HONO₂/H₂SO₄
C) (1) Cl₂, heat or light; (2) HONO₂/H₂SO₄
D) (1) HONO₂/H₂SO₄ ; (2) Cl₂, FeCl₃
E) Both A and B

28. Which of the following compounds would be most reactive toward ring nitration?

A) I
B) II
C) III
D) IV
E) V

29. Which would be the major product(s) of the following reaction?

A) I
B) II
C) III
D) I and II in roughly equal amounts
E) I and III in roughly equal amounts

30. Each of the five disubstituted benzenes is nitrated. In which of these cases does the arrow not indicate the chief position of nitration.

A) I
B) II
C) III
D) IV
E) V

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