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parga (jrp3484) HW07-VSEPR-POLARITY-VB vandenbout (51335) 1 This print-out should have 33 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points Consider the structural formula OH of phenol, the active ingredient in some oral anesthetics used in sore-throat sprays. What is the molar mass of phenol? 1. 94 g/mol correct 2. 50 g/mol 3. 89 g/mol 4. 17 g/mol Explanation: Remember that the shorthand notation means a phenyl group C 6 H 5 . The chemical formula is C 6 H 5 OH 002 10.0 points This is the condensed structural formula for acetaminophen, the active ingredient in the over-the-counter medication Tylenol. OH C CH 3 O N H What is the molecular formula of ac- etaminophen? 1. C 8 H 9 NO 2 correct 2. C 8 H 11 NO 2 3. C 8 H 8 NO 4. C 8 H 5 NO 2 Explanation: Remember that the shorthand notation means C 6 H 5 003 10.0 points This structure C C C C C C C C is the carbon skeleton for a structural isomer of octane with the hydrogen atoms omitted. What is the molecular formula of this isomer? 1. C 8 H 18 correct 2. C 8 H 24 3. C 8 H 8 4. C 8 H 17 Explanation: The structure is C H H H C C H C H H C H H H C H H H C H H H C H H H 004 10.0 points Consider the structure parga (jrp3484) HW07-VSEPR-POLARITY-VB vandenbout (51335) 2 C CH 3 O O S CH 2 C C CH 2 CH 2 CH 2 CH 3 of a COX-2 inhibitor. How many single bonds, double bonds, and triple bonds are represented by this condensed formula? 1. 31 single, 4 double, 1 triple correct 2. 31 single, 3 double, 1 triple 3. 13 single, 3 double, 1 triple 4. 13 single, 4 double, 1 triple Explanation: The benzene ring can be shown as C C C C C C H H H H H H 005 10.0 points The electronegativity of H is 1. a lot less than that of C. 2. a lot more than that of C. 3. about equal to that of C. correct Explanation: 006 10.0 points Which pair of bonded atoms has the largest dipole moment? 1. N N 2. C O 3. C C 4. C F correct 5. C N Explanation: Dipole moments result because of the differ- ence in electronegativity (EN) between bond- ing atoms. The bonds with the largest dipole will have the largest difference in EN. EN in- creases from bottom to top and left to right on the periodic table. C C and N N have the same EN, so there is no dipole moment. Between N, O, and F, F is the most EN, and has the largest difference in EN with C. Therefore, the C N bond has the largest dipole. 007 10.0 points Consider a 3-atom molecule A B A for which B has a total of only four valence elec- trons enough to make two bonds. Predict the A- B- A bond angle. 1. 180 correct 2. 90 3. 60 4. 109.5 5. 120 Explanation: 008 10.0 points What is the shape of COCl 2 ?... View Full Document

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