CHEM 3719 – Exam 1 – February 13, 2014 – Student Number 00__________NAME_________________
1. (4 pts) Calculate the formal charge on each N, O, and S in the structure below. All non-bonded
electrons are shown.
SH
O
H3N
O
2. (6 pts) Draw THREE more Resonance Structures for the carbocation intermediate shown below.
Use arrows to show "pushing of electrons". Each resonance structure you draw should have the
Positive Charge on a Different Carbon.
3. (5 pts) Draw an orbital energy level diagram for sp3 hybrid N. The electron count for unhybridized N
is 1s22s22p3.
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CHEM 3719 – Exam 1 – February 13, 2014 – Student Number 00__________NAME_________________
4. For each acid-base reaction shown below (the acid is on the left, the base is on the right, the
proton which is of interest is drawn in BOLD):
A) (8 pts) Draw the structures of the conjugate acid and conjugate base.
B) (4 pts) Decide whether the equilibrium favors the FORWARD reaction, the REVERSE reaction, or
NEITHER.
i.)
S H
ii) H3C C C H
O K
+
+
H3C Na
O
iii)
CH3CH2O H
+
O Na
O
iv)
N
CH3
Na NH2
H
5. (10 pts) Protonation of Imidazole at Nitrogen can produce two different conjugate acids. Draw the
structures of each conjugate acid. Which conjugate acid is more stable? Explain your choice
carefully.
H
N
N
H
H
Imidazole
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CHEM 3719 – Exam 1 – February 13, 2014 – Student Number 00__________NAME_________________
6. (10 pts) Draw a complete set of 6 Newman Projections for 1,1,2,2-tetrachloroethane, considering
rotation about the C1-C2 bond. Indicate which structure(s) are MOST stable and LEAST stable.
7. (3 pts) Circle any atoms in the structure below that are sp2 hybrid:
8. (6 pts) Draw and name all of the alkanes with the formula C6H14.
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CHEM 3719 – Exam 1 – February 13, 2014 – Student Number 00__________NAME_________________
9. (9 pts) Draw an acceptable structure for each of the following:
A) 3,8-diethyl-4,7-diisopropyl-2,2,9,9-tetramethyldecane
B) cis-1-sec-butyl-4-isobutylcyclohexane
C) bicyclo[4.2.0]octane
10. (9 pts) Provide an acceptable name for each of the following structures:
A)
B)
C)
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CHEM 3719 – Exam 1 – February 13, 2014 – Student Number 00__________NAME_________________
11. (6 pts) Rank the three isomeric alkanes shown below in order of STABILITY (Most to Least).
Briefly, explain how this order is determined experimentally.
12. (6 pts) Rank the three alcohols shown below in order of WATER SOLUBILITY (Highest to
Lowest). Briefly, explain your choice.
OH
OH
OH
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CHEM 3719 – Exam 1 – February 13, 2014 – Student Number 00__________NAME_________________
13. (8 pts) 4-Nitrophenol has a pKa of 7.1 in water. Draw FOUR more Resonance Structures for the
conjugate base of 4-nitrophenol (shown below). Use arrows to show "pushing of electrons". Each
resonance structure you draw should have the Negative Charge on a different atom.
O
H
N
O
O
+
-H
O
N
O
O
14. (8 pts) Draw and name 7 different dimethylcyclohexane isomers (including cis and trans isomers).
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