Chemistry Exam II, Fall 2016 - Multiple Choice and Short Answer Questions, Study Guides, Projects, Research of Chemistry

Download Chemistry Exam II, Fall 2016 - Multiple Choice and Short Answer Questions and more Study Guides, Projects, Research Chemistry in PDF only on Docsity! Name______________________________________________ Student ID Number___________________________________ LAB Sec. # ___; TA: __________; Lab day/time: __________ Dr. Bryan Enderle Fall 2016 CHEMISTRY 2C (Section B) Exam II CLOSED BOOK EXAM! No books, notes, or additional scrap paper are permitted. All information required is contained on the exam. Place all work in the space provided. A scientific calculator may be used (if it is a programmable calculator, its memory must be cleared before the exam). (1) Read each question carefully. (2) For Part I, there is not partial credit. There is partial credit for Part IV. For Part I & II, only answers marked on this cover page will be graded. You must also fill in your TA’s name at the top of the page. Failure to do either of these will result in a 10 point deduction. (3) The last page contains a periodic table and some useful information. You may remove this for easy access. (4) If you finish early, RECHECK YOUR ANSWERS! U.C. Davis is an Honor Institution Multiple Choice 1. A B C D E 2. A B C D E 3. A B C D E 4. A B C D E 5. A B C D E 6. A B C D E 7. A B C D E 8. A B C D E 9. A B C D E 10. A B C D E 11. A B C D E 12. A B C D E 13. A B C D E Possible Points Points M/C #1-9 27 points Page 4 24 points Page 5 22 points Page 6 06 points Page 7 09 points Page 8 15 points Page 9 11 points Total Score (114) Exam II Page 2 of 12 Part I: Multiple Choice, Concepts Circle the correct answer and enter your response on the cover – No partial credit 1. What is the overall order of a reaction with the following rate law? rate = k [A]2[B]½ / [C] A. ½ B. 1 C. 1½ D. 2 E. Cannot be determined 2. Which of the following is not a halogen containing compound? A. Teflon B. Freon C. Pewter D. PVC 3. Which of the following is true about noble gases? A. Noble gases are not completely inert. B. Larger noble gases that are readily ionizeable are more likely to react. C. Xe may react with highly electronegative elements, such as O or F. D. All of the above. 4. In which of the following oxyacids does the chlorine atom have an oxidation state of +1? A. hypochlorous acid B. chlorous acid C. chloric acid D. perchloric acid 5. Which statement is correct for the structure shown? A. Carbon number 1 is described by sp3 hybridization. B. The molecule contains 19 σ bonds. C. Carbon number 2 is described by sp2 hybridization. D. The molecule contains a total of five π bonds. E. Carbon number 7 is described by sp hybridization. 6. The correct units of the rate constant for a zeroth order reaction are: A. (Ms)-1 B. s-1 C. M/s D. (M2s)-1 Exam II Page 5 of 12 Part III: Short Answer Fill in the blank 14. (8 points) For the molecule below, fill in the table with the correct total number of π bonds, σ bonds, H atoms, and C atoms. π bonds σ bonds H atoms C atoms Total number in the molecule 2 31 17 9 15. (6 points) Reactions: fill in the blank with the appropriate molecule(s) and balance the reactions. 4 Li + O2 → 3 Ca + N2 → 2 NaCl → 16. (8 points) Draw the best Lewis structure for the following compounds. Include lone pairs. Remember to minimize formal charge! A. Main Group: XeF2O B. Organic Chemistry: (CH3)2CHCO2CH3 (ester) (should be lone pairs on oxygens below) 2 Li2O Ca3N2 2 Na + Cl2 Exam II Page 6 of 12 17. (6 points total) Answer the questions in the table below regarding the given reaction profile for the reaction A → G (consider the forward reactions only). A, B, C, D, E, F, and G represent molecules. Question Answer Which of the molecules represent intermediates? C, E Which of the molecules represent transition states? B, D, F Is the overall reaction endothermic or exothermic? Exothermic Which step is kinetically and thermodynamically unfavored? C → E or E → G. C → E Which step is the rate determining step? C → E Which step has the smallest activation energy? E → G Exam II Page 7 of 12 18. (9 points) Fill in the blank: in the column marked “Answer” to the left of each statement, write in the answer (element or effect) that best matches the statement. Answer Statement – Which element or effect is it? Inert Pair Effect 1. This effect explains the increased stability from CCl2, SiCl2, GeCl2 and PbCl2 and the decreased stability from CCl4, SiCl4, GeCl4 and PbCl4. B 2. This nonmetal is electron deficient and used as a dopant in semiconductor industry. It is sometimes used in fireworks to give a green flame. Po 3. The name of this metal comes from an Eastern European country. It has been historically used as anti-static agents for gramophone records. Such use is now rarer due to its extreme radioactivity and toxicity. P 4. This element has two major allotropes (white and red). Its illegal use is highlighted in the TV show Breaking Bad. Therefore, this element is on United States Drug Enforcement Administration’s list 1 chemicals. S 5. This element has wide range applications from fertilizer to chemical warfare. The oxides from vehicle emission is notoriously known to produce acid rain. Its compounds generally smell bad. The surface of Jupiter’s moon Io is coated with this element due to over 400 active volcanoes. Na 6. This metal forms a peroxide with oxygen. A common application is when its basic form is mixed with fat to make soap or detergent. Its use in ion exchange columns helps remove hard water precipitates. Ca 7. This metal is found in concrete, chalk, lime, hard water, stalactites, and stalagmites. Al 8. This metal is the most abundant in the earth’s crust. It is strong and light. Topaz, a prized gem, is the presence of ferric ions within an oxide of this metal. H 9. This element has few similarities with any group. It is colorless, tasteless, and odorless. 89% of all atoms in the universe are this element. 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