Test 2A Chemistry 21 - Dr. Kline November 15, 2017

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1 Test 2A Chemistry 21 - Dr. Kline November 15, 2017 This test consists of a combination of multiple-choice and other questions. There should be 21 questions on eight pages. Do not use your own tables, scratch paper, or other information. A periodic table and other information will be provided. Please turn off all cell phones and other devices that could make noise or vibrate. No food. No gum. Calculator OK. The test will end two hours and 15 minutes after it starts. You may use a template (stencil). No sharing of stencils once the exam starts. Multiple-Choice Questions. These 14 questions are worth three points each, for a total of 42 points. There is only one answer per question unless stated otherwise for a given problem. Answer each question by bubbling in the letter(s) corresponding to the correct choices on the provided answer sheet. If more than one answer is correct, bubble in all of the correct ones. It is not necessary to show work for these questions and, in fact, it will be ignored. You may write on the exam. 1. To which of the following compounds does the carbon NMR below correspond? DEPT-135 information is shown above each peak in the broad-band spectrum provided. a. b. c. d. It is impossible to tell. 2. What is the expected major mechanism in the following reaction? a. SN1 b. SN2 c. E1 d. E2 e. mix of SN1 and E1 3. What is the expected major mechanism in the following reaction? a. SN1 b. SN2 c. E1 d. E2 e. mix of SN1 and E1 Test 2A - Fall 2017 Page! 1 of! 8 Page Score

2 4. What is the expected major mechanism in the following reaction? a. SN1 b. SN2 c. E1 d. E2 e. mix of SN1 and E1 5. Which is expected to react the fastest in a reaction with NaSCH3? a. b. c. d. All react at about the same rate because they are all primary substrates e. It is impossible to tell 6. Which is expected to react the fastest in a solvolysis reaction with methanol? a. b. c. d. e. The compounds in choices b and c react at the same rate and are the fastest. 7. Which is expected to react the fastest in an E2 reaction with NaOEt and heating? a. b. c. d. e. 8. Which of the following carbocations is/are expected to rearrange? More than one answer may be correct. a. b. c. d. None 9. Which of the following is/are true for the reaction CH3CH2CH2Br + NaOCH3 > CH3CH2CH2OCH3+ NaBr? More than one answer may be correct. a. The rate law for the reaction is Rate = k[ch3ch2ch2br] b. The reaction is second order overall c. The reaction will be faster if acetone is used as the solvent than if methanol is used as the solvent. d. None of them. Test 2A - Fall 2017 Page! 2 of! 8 Page Score

3 10. Given that the following process is exothermic, which bond is stronger? a. C H b. H Br c. It is impossible to tell. 11. Consider the two reaction coordinate diagrams below, each for a different reaction. Which of the following statements is/are true regarding the two reactions? Reaction A Reaction B a. Reaction A occurs more rapidly. b. Process B is expected to have the larger equilibrium constant, K. c. In reaction A the first step is the rate-determining step. d. None 12. The reaction below is endothermic. Which of the statements is correct? a. The reaction is spontaneous ( G<0) at all temperatures. b. The reaction is non-spontaneous ( G>0) at all temperatures. c. The reaction is spontaneous at lower temperatures and non-spontaneous at higher temperatures. d. The reaction is spontaneous at higher temperatures and non-spontaneous at lower temperatures. e. It is impossible to tell. 13. Which of the following compounds is the most consistent with the infrared spectrum shown? a. b. c. d. e. Test 2A - Fall 2017 Page! 3 of! 8 Page Score

4 14. Which of the following compounds is the most consistent with the mass spectrum shown? a. b. c. d. Other Questions Each of the following questions is worth the indicated number of points, for a total of 58 points. Please be sure that you provide all of the information requested for each question points a. Draw the structure of 18-crown-6. b. Name the compound below, using one of the naming systems discussed in class. Circle or put a box around your final answer. c. Name the compound below, using one of the naming systems discussed in class. Circle or put a box around your final answer. Test 2A - Fall 2017 Page! 4 of! 8 Page Score

5 16. 9 points Draw the structure of the final major organic product from each of the following reactions or reaction sequences. Please put a box around your final answer in each part. a. b. c points. Draw curved arrows for each step of the following reaction mechanism. Test 2A - Fall 2017 Page! 5 of! 8 Page Score

6 points Each of the four spectra below corresponds to one of the compounds given. The mass spectrum shown only molecular ion and higher m/z peaks. DEPT information is not provided for the carbon NMR. Match each spectrum with a compound by writing the letter for the compound to the right of the spectrum. Provide a brief justification for each spectrum. A B C D E F G Test 2A - Fall 2017 Page! 6 of! 8 Page Score

7 19. 5 points Determine the molecular formula of the compound with the following infrared and mass spectra. Only molecular ion and higher m/z peaks are shown in the mass spectrum. Show work/logic! Please put a box around your final answer. Test 2A - Fall 2017 Page! 7 of! 8 Page Score

8 20. 6 points. Write a plausible mechanism for the following transformation points Provide a synthesis of the compound on the right from the compound on the left. Include structures of any intermediate products that could be isolated. Test 2A - Fall 2017 Page! 8 of! 8 Page Score