Chemistry 110 Name _______________________ Practice Exam 2A Section _______________________ Midterm 1 Signature _______________________ IMPORTANT: On the scantron (answer sheet), you MUST clearly fill your name, your student number, section number, and test form (white cover = test form A; yellow cover = test form B). Use a #2 pencil. There are 28 questions on this exam. Check that you have done all of the problems and filled in the first 28 bubbles on the scantron. The maximum score on this exam is 28 points. Your score will be reported in percents (max 100%). Exam policy • This cover sheet must be signed and handed in with your answer sheet for your exam to count. • Calculators with text-programmable memory are not allowed. • Relevant data and formulas, including the periodic table, are attached at the end of this exam. • Your grade will be based only on what is on the scantron form. • The answer key will be posted on the web after the exam (under "Exam Schedule"). Hints • As you read the question, underline or circle key words to highlight them for yourself. Avoid errors from "mis-reading" the question. • Pay attention to units and magnitudes (decimal places) of numbers obtained from calculations. • There is no penalty for guessing.CHEMISTRY 110 PRACTICE EXAM 2A --------------------------------------------------------------------------------------- 1. What is the total number of valence electrons present in PO43−? A. 24 B. 27 C. 30 D. 32 E. 33 --------------------------------------------------------------------------------------- 2. Which of the following is an incorrect Lewis structure for the most stable state of the molecule or ion shown? OCClClSOC N-COH O HA.B.C.D.E.C O --------------------------------------------------------------------------------------- 3. Draw Lewis structures for NO2+, NO2− and NO3−. Based on the interpretation of the Lewis structures, put these in order of increasing bond order. A. NO2+ < NO2− < NO3− B. NO2+ < NO3− < NO2− C. NO2− < NO3− < NO2+ D. NO3− < NO2− < NO2+ E. NO2− < NO2+ < NO3− ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 4. Which of the following best describes propane, butane, and octane? A. The molecules contain only C, O and H. B. The molecules contain only C and H and are isomers of each other. C. The molecules contain only C and H and at least 1 double bond. D. The molecules contain only C and H and only single bonds. E. The molecules share no common characteristics. --------------------------------------------------------------------------------------- 5. Which of the following best describes the electron domain geometry of bromine pentafluoride? A. trigonal bipyramidal B. seesaw-shaped C. tetrahedral D. square pyramidal E. octahedral --------------------------------------------------------------------------------------- 6. Put these in order of increasing electronegativity. Ca Si O Al Ba A. Ba <Ca < Al < Si < O B. Ca <Ba < Si< Al < O C. O < Al < Si < Ca < Ba D. Al < Ca < Ba < Si < O E. Ba < Ca < O < Al < Si ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 7. What is the empirical formula for the compound drawn below? A. C3H4O B. C9H12O3 C. C8H9O3 D. CHO E. C9H11O3 --------------------------------------------------------------------------------------- 8. Which of the following molecules possesses the most number of equivalent resonance structures? A. SO32− B. NO2 C. CH4 D. CO2 E. SO2 --------------------------------------------------------------------------------------- 9. Which of the following is correct regarding structural isomers? i. They have different molecular formulas. ii. They have the same connectivity of the atoms. iii. They have the same molar mass. A. i only B. ii only C. iii only D. i and iii E. all of these are true. --------------------------------------------------------------------------------------- OOOH--------------------------------------------------------------------------------------- 10. An unknown compound is analyzed and found to contain C, H, and Br. Upon further analysis, it is also found to be 45.9% carbon and 3.21% hydrogen. Which of the following could be the unknown compound? --------------------------------------------------------------------------------------- 11. Which of the followings pairs are isomers? A. II only B. II and III only C. I, II and IV only D. I, II, III and IV only E. II, III and IV only --------------------------------------------------------------------------------------- I.II.OHOHClClIII.IV.--------------------------------------------------------------------------------------- 12. Which one of the following molecules does NOT have a geometric isomer? --------------------------------------------------------------------------------------- 13. Which functional group is NOT present in the compound shown below? A. amide B. carboxylic acid C. ester D. amine E. alcohol ---------------------------------------------------------------------------------------14. Which of the following molecules will adopt a trigonal planar geometry? I. BF3 II. ClF3 III. NH3 A. I only B. II only C. III only D. I and II only E. I, II, and III --------------------------------------------------------------------------------------- 15. Which orbital hybridization(s) of the C atoms is (are) exhibited in the molecule shown below? i. sp ii. sp2 iii. sp3 A. i and ii only B. ii and iii only C. i and iii only D. iii only E. all three are exhibited ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 16. Which figure best illustrates the hybridization of the central sulfur atom in sulfur dioxide (SO2) and the central carbon atom in carbon disulfide (CS2)? i.ii.iii. SO2 CS2 A. iii i B. ii ii C. i iii D. ii i E. i i --------------------------------------------------------------------------------------- 17. Which of the following choices