Spring 2013
Chem 302
Houseknecht
Name_____________________________________
I _______________________________________ (sign name) affirm that my work upholds the
highest standards of honesty and academic integrity at Wittenberg, and that I have neither given
nor received any unauthorized assistance.
Exam 1 – February 1, 2013
There are 6 pages (including this one) and 9 questions on this exam. Read each question carefully
before beginning. Show work for partial credit. A periodic table is attached to the end of this exam.
You may remove it and use it for scrap paper. You may also use the lower portion of this cover page
as scrap paper. If you would like any more scrap paper please ask. Good luck.

Spectra on this exam have been obtained from the SDBS website or simulated,
(http://www.aist.go.jp/RIODB/SDBS).
Exact Masses
Hydrogen – 1.00783
Carbon – 12.00000
Nitrogen – 14.00307
Oxygen – 15.99491
Alkenes in fingerprint region
Monosubstituted – 1000 and 900 cm-1
Disubstituted
Cis – 750-650 cm-1
Trans – 950 cm-1
Trisubstituted – 850-790 cm-1 (medium)
Aromatics in fingerprint region
Monosubstituted – 770-730 cm-1 AND 710-690 cm-1
Ortho (1,2) – 770-735 cm-1
Meta (1,3) – 850-810 cm-1 AND 710-690 cm-1
Para (1,4) – 840-810 cm-1
Typical coupling constants
Alkenes
cis ~ 6-12 Hz
trans ~ 12-18 Hz
gem ~ 0-3 Hz
allylic ~ 4-10 Hz
Aromatics
ortho (1,2) ~ 6-8 Hz
meta (1,3) ~ 1-3 Hz
para (1,4) ~ 0-1 Hz
Spring 2013
Chem 302
Houseknecht
1. (10 pts) Answer the following multiple choice questions. Show thought process for partial credit.
a. Which of the following peaks are expected in the MS of 2-methylbutan-2-ol? Circle all
correct answers.
i. 86
ii. 73
iii. 59
iv. 29
b. Cortisone is a molecule containing only C, H, and O with eight degrees of unsaturation and
an exact mass of 360.1937. What is its molecular formula?
i. C24H24O 3
iii. C21H28O5
ii. C23H20O 4
iv. C20H24O 6
c. Which of the following bond types has the greatest intensity in infrared spectroscopy?
i. C=O stretch
iii. C-C stretch
ii. C=C stretch
iv. C-H stretch
d. Predict the number of carbon resonances you would expect in the 13C NMR spectra of
methylcyclopentane.
i. 2
ii. 4
iii. 5
iv. 6
e. The frequency of light absorbed by a 1H nucleus in NMR is increased by which of the
following. Circle all correct answers.
i. Nearby, non-equivalent nuclei in the  spin state
ii. Increased electron density
iii. Nearby electronegative atoms
iv. Increased applied magnetic field, Bo
2. (12 pts) Provide a structure for three of the peaks in the MS of heptan-3-one below.
m/z
27.0
28.0
29.0
39.0
41.0
43.0
57.0
71.0
72.0
85.0
114.0
Int
22.8
8.2
79.1
8.8
33.7
15.2
100.0
5.6
32.9
43.3
14.0
Spring 2013
Chem 302
Houseknecht
3. (12 pts) Predict three important peaks in the IR spectra of the ester below and the specific bond
vibrational responsible for each.
4. (4 pts) Explain why the C=O stretch of pent-3-en-2-one occurs at a lower frequency than that of
pent-4-en-2-one.
5. (12 pts) Predict the multiplicity and chemical shift of each type of proton in isopropyl propanoate.
Label each for clarity.
Spring 2013
Chem 302
Houseknecht
6. (12 pts) The HC region of the 1H NMR spectra of bromobenzene is shown below. Draw a tree
diagram that accounts for the observed multiplicity of HC and calculate the JAC and JBC values in
Hz. Show calculations for complete credit.
7. (12 pts) Provide the structure of the molecule that has the mass and 13C NMR spectra shown below.
Show work for complete credit.
m/z
27.0
39.0
41.0
42.0
43.0
122.0
124.0
Int
25.6
9.0
31.0
7.7
100.0
8.6
8.3
Spring 2013
Chem 302
Houseknecht
8. (14 pts) Provide the structure of the molecule that has the spectra shown below. Show work for
complete credit.
3H, s
3H, s
3H, t
2H, q
s
Spring 2013
Chem 302
Houseknecht
9. (12 pts) Provide the structure of the C5H10O molecule that has the 1H NMR spectra shown below.
Show work for complete credit.
3H, s
3H, t
2H, t
2H, sextet
Extra Credit (5 pts) Explain why the protons at C1 of but-1-ene are spin-spin coupled to one another
with a coupling constant of 2.5 Hz, but those of 2-methylpropene are not spin-spin coupled.