Last, First:______________________ CHEM 2321 Exam 1A
100_____________________ Organic Chemistry I 09/24/2019
Part I. Multiple Choice Questions XXXXXXXXXXpts. each (90 points) Answer these questions on
a Scantron 882-E form in pencil. Write your NAME and Exam 1A on the scantron.
1. What is the chemical formula for Vitamin
B2?
a) C15H18N4O6
) C15H20N4O6
c) C15H18N4O6
d) C17H20N4O6
e) C17H22N4O6
2. How many sp2 Oxygens are in B2?
a) 0
) 1
c) 2
d) 3
e) 4
3. There are ____ pi (Ï€) bonds in the
structure above (Vitamin B2)?
a) 3
) 4
c) 5
d) 6
e) 7
4. What best describes the overall dipole
moment for the following molecule?
F
a. b.
c. d.
e. 0 D (no dipole)
5. What is the overall dipole moment that
co
esponds to the following molecule?
O
O
a. b.
c. d.
e. 0 D – no dipole
Questions 6-8. What are the geometries for
the following bold and underlined atoms?
a. linear d. trigonal pyramidal
. tetrahedral e. trigonal planar
c. bent
6. CH3CO2H e.
7. H2O c.
8. H2CCCH2 a.
Last, First:______________________ CHEM 2321 Exam 1A
100_____________________ Organic Chemistry I 09/24/2019
9. Which bond-line structure, as drawn, is
identical to the given Newman projection?
HH
CH3F H
CH3
a.
F
b.
F
c.
F
d.
F
10. Which of the given resonance forms
contributes most to the real structure of
C6H4FO-1?
a.
O
F
b.
O
F
c.
O
F
d.
O
F
e. both (b) and (d)
11. How many resonance forms of the
cyclopentadienyl anion can be drawn,
including the given structure?
a. 2 d. 5
. 3 e. 6
c. 4
12. Choose the most acidic acid
a. d.
. e.
c.
13. What is the value of Keq in the reaction
elow.
O O+ +
a) K = 1
) K > 1
c) K < 1
14. Which of the following best describes a
Lewis Acid?
a) A molecule that can accept a lone pair
of electrons
) A molecule that can accept a lone pair
of electrons
c) A molecule that can donate a proton
d) A molecule that can accept a proton
15. Which of the following mechanisms is
drawn most accurately (B: = Base, A-H =
Acid)?
a)
B: H A B AH+ +
) B: H A B AH
+ +
c) B: H A B AH
+ +
d) B: H A B AH
+ +
Last, First:______________________ CHEM 2321 Exam 1A
100_____________________ Organic Chemistry I 09/24/2019
16. Rank the labeled hydrogen atoms from
the most acidic to least acidic proton.
Ha
Hb O
Hd
O
Hc
a. Ha>H
Hc>Hd d. H
Hc>Hd>Ha
. Hd>Hc>H
Ha e. Hc>Hd>Ha>Hb
c. Hc>Hd>H
Ha
XXXXXXXXXXSelect the proper name for the
following two molecules.
17.
a) 2-methyl-5-isopropylhexane
) 2-isopropyl-5-methylhexane
c) 1,4-diisopropylbutane
d) 2,3,6-trimethylheptane
e) 2,5,6-trimethylheptane
18.
a. 4-t-butyl -5-isopropyl-5-methyloctane
. 5-t-butyl-4-isopropyl-4-methyloctane
c. 4-t-butyl-2,3-dimethyl-3-propylheptane
d. 4-isopropyl-2,2,4-trimethyl-3-propyl
heptane
e. 4-isopropyl-5-methyl-4-t-butyloctane
Last, First:______________________ CHEM 2321 Exam 1A
100_____________________ Organic Chemistry I 09/24/2019
Part II. Questions XXXXXXXXXXpoints each) Answer Questions 19 and 20 in the space provided
on this exam. Clearly write your answer. Multiple answers will not be graded. For the following
problems, show your work where possible. This allows me to award partial credit. I will not
econsider grades for answers written in pencil, but you are welcome to use any writing utensil
that you wish.
19.
a. Draw all resonance forms that describe the structure below (4 points):
O
NH2HO
. Which of the resonance forms (besides the one given) is most stable? Explain your answer
iefly. (2 points)
c. considering all of the resonance forms you’ve drawn for 19a., what partial charges (δ+ or δ-)
would you expect to find on the molecule and where? Please draw your partial charges on the
molecule, below. (2 points)
O
NH2HO
Last, First:______________________ CHEM 2321 Exam 1A
100_____________________ Organic Chemistry I 09/24/2019
20. a. Draw the structure of 2,5-dimethylhexane in the space below. (2 points)
. Analyzing the C2-C3 of this molecule, draw I a Newman projection showing the highest
potential energy conformational isomer, and II a Newman projection showing the lowest
potential energy conformational isomer (6 points)
I XXXXXXXXXXII.