/60 /100. Last 4 digits of Banner No. Score. I. Multiple Choice ( /20) II /20 III /10 IV /10. Total score. Chem 2320 Exam 2. February 20, 2007.

Transcription

1 Chem 2320 Exam 2 February 20, 2007 ame: (first) (last) (Please print) Last 4 digits of Banner o. Score I. Multiple Choice ( /20) /60 II /20 III /10 IV /10 Total score /100 1

2 I. Multiple choice questions. (3 points each). Please put your answers on Scantron sheet. Your score will be graded based only on your answers from Scantron sheet. 1. What's the structure of m-chloroaniline? C 3 2 (e) one of the above 2. What's the structure of p-nitrobenzoic acid? C 2 S 3 C S 3 C 2 C (e) one of the above 3. What is the correct order of decreasing reactivity (fastest to slowest) toward the electrophilic aromatic substitution for the following compounds? C 2 C 3 C 3 I II III IV (e) I>II>III>IV II>I>IV>III III>II>IV>I IV>III>II>I one of the above 2

3 4. What could be the product for the following reaction? 1) Al 3 2) 2 product? (e) one of the above 5. For the following compound, which nitrogen has lone-pair electrons that can resonance onto the aromatic ring? b c d (e) a itrogen indicated by arrow a itrogen indicated by arrow b itrogen indicated by arrow c itrogen indicated by arrow d one of the above Answer Q.6 to Q.9 based on the following scheme. I a Cu II A 3 2 S 4 2 Pt/C a) heating b) - III 2 Pt/C 2 2 3

4 6. What could be reagent A?, 2 S 4 BS, heating 2 / Fe 3 2 / K, 2 (e) one of the above 7. What could be compound I? (e) one of the above 2 8. What could be compound II? (e) one of the above 9. What could be compound III? (e) one of the above 10. What could be used as the reagent for the following reaction? reagent 2 /Fe 3 (C) 2 Mn 2 K 2 Cr 2 7 (e) none of the above 4

5 11. What could be the major product from the following reactions? C K, 2 heating Major Product? Al 3 C 3 C 3 C 3 3 C (e) one of the above 12. What is the correct order of decreasing reactivity (fastest to slowest) toward nucleophilic aromatic substitution for the following compounds? I II III IV IV>III>II>I I>II>III>IV III>II>IV>I II>III>IV>I (e) one of the above 13. What should be the major product for the following reaction? Major product? Al 3 (e) one of the above 5

6 14. Which of the following molecules are aromatic compounds? I II III IV V VI VII VIII (e) III, IV, VI, VII, VIII II, IV, V, VII, VIII II, III, VI, VII II, III, VI, VII, VIII one of the above 15. Which of the following molecules are aromatic compounds? S I II III IV V VI VII VIII IX X XI XII (e) I, II, III, IV, V, VI, VII, X, XII I, II, III, V, VII, VIII, IX, X, XII I, II, III, VI, VIII, X, XI, XII I, II, III, IV, V, VI, VIII, X, XI one of the above 6

7 16. What is the correct order of decreasing acidity for the following compounds (from the most to the least)? I II III IV V VI C 2 C 2 C 2 C 2 C 2 C 2 C 3 C 3 C 2 V>I>VI>IV>III>II IV>V>IV>III>II>I II>III>IV>VI>V>I III>II>IV>VI>V>I (e) one of the above 17. Which of the following is not the resonance structure of intermediate from the listed electrophilic aromatic substitution? C 3 2 Fe 3 C 3 C 3 C 3 C 3 C 3 C 3 I II III IV V (e) I II III IV V 7

8 18. What could be the product for the following reaction? C 3 a 2 liquid 3 Product? C 3 (e) one of the above C 3 C 3 2 C 3 2 C 3 C 3 C 3 C 3 C What could be the product for the following reaction? K 2 Cr 2 7 +, 2 heating Product? C 2 (e) none of the above 20. What could be the product for the following reaction? Zn (g), heating Product? (e) one of the above Continue to the next page 8

9 II. Use the table on the next page and provide the correct structures of compounds and reagents. o partial point will be awarded if you place your answer in the wrong box. (20 points) IV III BF 4 3 P 2 2 A 2 a B 3 2 S 4 Cu 3 C Al 3 I II VI a 2 Cr 2 7 +, heat V 2 2 -, heat BS peroxide heat t -Bu - K + VII C C 9

10 I: II: III: IV: V: VI: VII: A: B: C: Continue to the next page 10

11 III. Propose an electron-pushing mechanism for the following reaction. You must show how the diazonium salt can be formed. (10 points) C 2 C 2 a 2 C 2 Continue to the next page 11

12 IV. Propose an electron-pushing mechanism including the formation of required electrophile for the following reaction. Indicate the rate determining step. Indicate clearly the most significant resonance structure of intermediate that will explain the observed regioselectivity (the formation of para disubstituted benzene). (10 points) 3 C 3 C Al 3 3 C C 3 12