Exam 1 (1:17) KEY - Practice Exam/Practice Exam Answers for CHEM322A PDF

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Practice Exam/Practice Exam Answers for CHEM322A...

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Chemistry 322A Exam I 01/30/2017 Print the following information:

First Letter of Last Name

Name: ____________________________________ Lab TA’s Name: ____________________________ Write and bubble in your USC ID

For TA use only

ID

Score

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Sign Below: I certify that I have observed all the rules of Academic Integrity while taking this examination. Signature:

Question

Points

1

7

2

12

3

12

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8

5

8

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16

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Total

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Score

Grader

Instructions: 1. The penalty for sitting in a seat you were not assigned is a 0 on the exam that will not be dropped. 2. A model kit, TI 30x IIS and/or Casio FX-260 can be used at any time. The penalty for using another calculator type is a 0 on the exam that will not be dropped. 3. Except for a model kit and calculator, electronic devices and course-related material (crib sheets, notes, books, etc.) are prohibited. If these prohibited materials are in your field of vision for any reason at any time you will receive an F in this class. This is your last chance to clear completely your line of sight. 4. Use black ink, blue ink or pencil; use of other ink colors or White-Out is -10 points. 5. A periodic table is on the last page (page 7) of the exam. 6. There are 10 problems on pages 3 - 6. Ensure your exam is complete before you begin. 7. If you need to continue an answer on the back of a page, specify this with a note. 8. Clearly indicate your answer; if you provide ≥2 answers, the graders will only grade the incorrect or lowest-scoring answer. 9. Structures in which carbon’s octet is expanded will receive no credit. 10. When time is called, stop working on your exam immediately. USC policy states the penalty for continuing to write after time is called is an F in the course. 11. If you finish early and let the door slam on your way out of the exam room, your score will be docked 10 points. 2

1. (7 pts) Rank the following compounds from highest to lowest dipole moment: Problem 168

A

B

C

D

__ > __ > __ > __ highest

lowest

D>B>A>C All correct, in correct order, 7/7 One out of order, 4/7 Anything else, 0/7 2. (12 pts) Draw the structure for a compound that has… Problem 3-4, 3-14, 3-59, 3-61 6 each, all-or-nothing a. …a molecular formula of C6H14 and two tertiary hydrogens.

3

b. …a molecular formula of C8H18 and only primary hydrogens.

4

3. (12 pts) What is the hybridization of each highlighted atom? Problem 1-64 2 pts ea

4. (8 pts) From which of the following compounds can NaH (sodium hydride) remove a proton in a reaction that favors product formation? Circle those that would be deprotonated. The pKa of H2 is 35. Problem 2-67 2 pts each, only CH2CH2 not circled

5

CH3CH2CH2OH

CH2CH2

pKa = 16

pKa = 44

CH3CH2COOH

CH3CH2CH2SH

5. (8 pts) Draw the product(s) of this reaction. Use a curved arrow or arrows to show where the pair of electrons starts and where it ends up. Problem 2-51

AlCl3

+

Cl–

⇄

4 pts arrow drawn unambiguously arrow ambiguous in any way (up to the grader’s discretion not the student’s), 0

4 pts product missing/incorrect formal charge, -1 [AlCl4]-, -1

6

6. [Two versions] (16 pts) Provide an IUPAC name for a – c and a common name for d. Problems 3-73, 3-80, 3-83, 3-87 4 pts each wrong parent, 0/4 alphabetization/spelling/punctuation error, -1 ≥2 errors in a single problem, 0/4

a.

2-bromo-4-methyl-1-propylcyclohexane wrong locants only error, 2/4 2-bromo-4-methyl-1-propylhexane, 1/4

b. 6-(1,2-dimethylbutyl)dodecane 6-(wrong group name)dodecane, 1/4 c. 7

4-ethoxybutan-1-ol or 4-ethoxy-1-butanol 4-ethoxybutanol, 2/4 1-ethoxy-4-butanol, 1/4 4-methoxy-1-butanol, 1/4 no numbers at all, 0/4

d. sec-butylethylamine isobutylethylamine, 1/4

8

6. [Two versions](16 pts) Provide an IUPAC name for a – c and a common name for d. Problems 3-73, 3-80, 3-83, 3-87 wrong parent, 0/4 alphabetization/spelling/punctuation error, -1 ≥2 errors in a single problem, 0/4

a.

1-chloro-2-ethyl-4-methylcyclopentane wrong locants only error, 2/4 1-chloro-2-ethyl-4-methylpentane, 1/4 b. 5-(1-ethylpropyl)decane 5-(wrong group name)decane, 1/4

9

c.

4-ethoxybutan-1-ol or 4-ethoxy-1-butanol 4-ethoxybutanol, 2/4 1-ethoxy-4-butanol, 1/4 4-methoxy-1-butanol, 1/4 no numbers at all, 0/4

d. isobutyldimethylamine isopropyldimethylamine, 1/4 sec-butyldimethylamine, 1/4 tert-butyldimethylamine, 1/4

7. (9 pts) In each pair (a - c) circle the stronger acid. Problem 2-70 3 each

10

11

8. (9 pts) In each pair (a - c) circle the stronger base. Problem 2-53 3 each

a. HO– or HS–

HO–

b. CH3COO– or CF3COO– c. CH3O– or CH3NH–

CH3COO– CH3NH–

9. (10 pts) For the following compound, draw the conjugate acid and conjugate base. Problem 2-58, 5 each, -1 per missing/incorrect formal charge

conjugate base

conjugate acid

10. (9 pts) There are three constitutional isomers with the molecular formula C 2H2Br2. Draw their structures. Use skeletal or Lewis structures only, condensed structures will receive no credit. Problem 1-78

3 pts each Condensed structure, 0/3 per

12

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