Chemistry 234 Exam 1 (Gray) The Periodic Table

Transcription

1 ame: Last First MI Chemistry 234 Exam 1 (Gray) Summer 2017 Dr. J. sbourn Instructions: The first 21 questions of this exam should be answered on the provided Scantron. You must use a pencil for filling in the Scantron sheet. Ensure all erasures are complete. Any questions left blank will be marked incorrect. Answer the remaining questions on the exam itself. Show all work and provide complete explanations. Please write your name on: The first page (Exam Cover Page) The second page (Grading Page) The Scantron Sheet Circle your Last ame Please bubble in your WVU Student ID umber on your Scantron sheet. The Periodic Table Exams will be returned by placing them alphabetically on the table at the front of ark 208. Your grade will not be visible as it is on the second page. If, however, you have a privacy concern, check the box below and all of your exams will be held back so that you can pick them up privately. old Back My Exams *Please do not rip off this cover sheet* Gray - Page 1 of 8

2 ame: Last First MI Grading Page (Exam 1): Page Points Possible Points Earned Multiple Choice (3-6) TTAL 100 Gray - Page 2 of 8

3 Multiple-Choice Choose the one best answer for each of the following questions. Record each answer on your Scantron sheet. Additionally, circle each answer on this exam. (2 points each) 1. Which one of the following is a bridgehead carbon? a b c d 2. Which of the indicated atoms have a p-orbital? I II III IV a. I and II b. I, II, and III c. I and III only d. I, II, III, and IV e. I, II, and IV 3. What is the major product of the following reaction? a b c d 4. Which one of the following dienophiles would you expect to be the least reactive in a normal Diels-Alder reaction? C 3 a b c d e 5. Arrange the following dienes in order of increasing stability. I II III a. I < III < II b. II < I < III c. I < II < III d. III < I < II e. III < II < I Gray - Page 3 of 8

4 6. The compound shown below is non-aromatic because: a. it is not planar b. it is not completely conjugated (i.e. the lone pair is in an sp 3 orbital) c. it has 6p electrons. d. a, b, and c e. both a and b 7. Which of the following correctly represents the direction of the bond dipole (d+ d-)? a b 8. What is the hybridization of the nitrogen in the amide shown below? a. p b. sp 2 c. sp d. sp 3 e. s 9. Which one of the following dienes is the most reactive in a normal Diels-Alder reaction? 2 2 a b c d 10. The compound shown below has atoms in conjugation. a. 4 b. 5 c. 6 d. 8 e. 9 Gray - Page 4 of 8

5 11. Consider the molecule shown below and determine the orbital location for each indicated species. S Carbocation S lone pair 1 S lone pair 2 a. sp 2 orbital sp 2 orbital sp 2 orbital b. p orbital p orbital p orbital c. p orbital sp 3 orbital sp 2 orbital d. p orbital sp 2 orbital sp 2 orbital e. p orbital sp 2 orbital p orbital 12. Which one of the following is not a resonance structure of the compound shown in the box below? a b c d 13. Which compound shown below will undergo electrophilic aromatic substitution at the fastest rate? a b c d e Use the reaction shown below to answer questions (14-16) If the reaction were carried out at -78 C, what would be the major product(s)? a. I b. II c. III d. I and II e. I, II, and III I II III Gray - Page 5 of 8

6 15. If the reaction were carried out at 40 C, what would be the major product(s)? a. I, II, and III b. I and II c. II and III d. III only 16. Which product (if any) is both a kinetic and a thermodynamic product? a. I b. II c. III d. I and II e. one For questions 17-21, select the appropriate reagent from the reagent bank to accomplish each of the following transformations. ote that some answers may require you to bubble in two letters. Record each answer on your Scranton sheet! Br Al 3 Reagent Bank S 3 2 S 4 a b c Br 2 FeBr 3 Al 3 19 d e ab 20 S 3 BS light (hν) a 2 Cr S 4 ac ad ae 21 Br Br a Br 2 (1 equiv) 3 2 S 4 bc bd be Gray - Page 6 of 8

7 Completion Section Answer the questions below in the spaces provided. 22. Provide the IUPAC name or structure for each compound below. (3 points each) a. 2 b. I c. ortho-ethylanisole d. 1-fluoro-2-methyl-4-nitrobenzene 23. Consider the molecule shown below and answer the following questions. a. Draw two additional resonance structures. (4 points) b. Circle the resonance structure that is the major contributor to the resonance hybrid. (1 point) c. Draw a picture of the molecule showing the location of every p-orbital. (2 pts) d. ow many atoms are in conjugation? (1 pt) e. What is the hybridization of the oxygen? (1 pt) f. In what type of orbital does each of the oxygen lone pairs reside? (2 pts) 24. Draw the complete electron pushing mechanism for the reaction shown below. (7 points) + C 3 Al 3 C 3 Gray - Page 7 of 8

8 25. For each compound below, determine if it is aromatic, anti-aromatic, or non-aromatic. For aromatic and anti-aromatic compounds, indicate the number of π-electrons in conjugation. (2 points each) π e- π e- π e- π e- 26. What two starting materials would be required to prepare the following product via a Diels-Alder reaction? (3 points) 3 C 3 C 27. The reaction shown below produces four different potential products. Draw each of these products then place a check in the box(es) containing the thermodynamic product(s). (5 points) 28. Predict the major product(s) for each reaction shown below. If the reaction does not proceed under the specified conditions, write o Reaction (2 points each) a b. + c. Al 3 a 2 Cr S 4 d. 3 2 S 4 2 Pd/C Gray - Page 8 of 8