CHEMISTRY 204
HOUR EXAM III
Dr. Christine Yerkes
April 26, 2006
Spring 2006
NAME _______________________________
SIGNATURE _________________________
QUIZ TA _____________________________
Test Form A
A.
DO NOT open the exam until you are instructed to do so.
B.
The exam has 11 pages. After you are instructed to begin the exam, please check
to see that you have all 11 pages.
C.
You should also have a list of helpful information and equations and a periodic
table.
D.
The exam contains 45 questions. The point value of each question appears next
to the question number.
E.
Academic dishonesty. If cheating is observed, any students involved will receive
a zero on the exam.
INSTRUCTIONS FOR THE ANSWER SHEET.
1.
Use a soft lead pencil and make dark marks. Do NOT use a pen. Erase all changes
completely.
2.
Print your Name in the appropriate designated spaces, then blacken in the letter
boxes below each printed letter, last name first, then your first name initial.
3.
Under Network ID print your University Network ID starting from box #1, then
blacken in the corresponding letters, numbers and/or dashes.
4.
Sign your name (do not print) on the line provided. Your signature indicates that
this is your work. Print your name underneath it.
5.
Put your section number under course code:
AQA = 00001
AQF = 00005
6.
AQB = 00002
AQG = 00006
Mark only one answer for each question.
AQC = 00003
AQI = 00007
AQD = 00004
AQJ = 00008
Useful Information:
order
Rate Law
Integrated form
plot
slope
k (units)
half-life
0
rate = k
[A]t - [A]0 = -kt
[A] vs. t
-k
mol/L s
t1/ 2 
[ A] 0
2k
1
rate = k[A]
ln[A]t - ln[A]0 = -kt
ln[A] vs. t
-k
1/s
t1/ 2 
ln 2
k
2
rate = k[A]2
1/[A]t - 1/[A]0 = kt
1/[A] vs. t
k
L/mol s
t1/ 2 
1
k[A] 0
Arrhenius equation:
k = pze  Ea / RT
R = 8.314 J/K mol
k = Ae  Ea / RT
K = °C + 273
ln k = ln A - Ea/RT
ln (k2/k1) = (Ea/R)(1/T1 - 1/T2)
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 1
One component of smog that is especially irritating to eyes is formaldehyde, CH2O,
which is formed in the reaction between ozone, O3, and ethene, C2H4.
C2H4 (g) + O3 (g) → 2CH2O (g) + ½ O2 (g)
The initial rate was studied as -d[C2H4]/dt, and the results at 298 K are shown below.
Use this information to answer the next three (3) questions.
expt. [O3] (M)
[C2H4] (M) initial rate (Ms-1)
-7
1
0.5 x 10
1.0 x 10-8
1.0 x 10-12
2
1.5 x 10-7
1.0 x 10-8
3.0 x 10-12
-7
-8
3
1.0 x 10
2.0 x 10
4.0 x 10-12
1. (2) The rate law for this reaction is:
a) rate = k[C2H4][O3]
d) rate = k[C2H4]2[O3]
b) rate = k[C2H4]2
e) rate = k[C2H4]
c) rate = k[O3]
2. (2) In experiment 3, what is the rate of appearance of oxygen, at 298 K?
a) 1.0 x 10-12 Ms-1
d) 8.0 x 10-12 Ms-1
b) 2.0 x 10-12 Ms-1
e) none of these
c) 4.0 x 10-12 Ms-1
3. (3) If the initial concentrations of both C2H4 and O3 are 1.0 x 10-7 M, what is the
initial rate of the reaction, as measured by -d[C2H4]/dt, at 298 K (in Ms-1)?
a) 1 x 10-12
b) 2 x 10-12
c) 1 x 10-11
d) 2 x 10-11
e) 1 x 10-10
A certain reaction is 40% complete after 50 minutes and is 57% complete after 100
minutes. Assume an initial concentration of 1.0 M. Use this information to answer the
next three (3) questions.
4. (3) The rate law for this reaction is:
a) zero order
e) none of these
b) first order
c) second order
d) third order
c) 75.0 min
d) 86.0 min
5. (2) The half time for the process is:
a) 60.0 min
e) none of these
b) 68.0 min
6. (2) The rate constant for the reaction (with no units) is:
a) 1.00 x 10-2
e) none of these
b) 1.33 x 10-2
c) 1.85 x 10-2
d) 8.25 x 10-3
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 2
Select the appropriate graph for the following choices for a reaction of the type
AB
c)
b)
a)
d)
e) none of these
7. (2) The ln[A] vs t for a reaction which is second order in A
8. (2) k vs T (K) for a zero order reaction
9. (2) [B] vs t for a first order reaction
10.(2) [B] vs t for a zero order reaction
11.(2) ln k vs 1/T
12.(2) 1/[A] vs t for a second order reaction
13.(2) How many different dibromination products are formed in the reaction between
cyclobutane and bromine in the presence of uv light? (omit optical isomers).
C4H8 + Br2  C4H6Br2 + 2 HBr
a) 2
b) 3
c) 4
d) 5
e) 6
14. (2) Saran wrap, an addition polymer, has the structure shown below.
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
n
What is the correct, IUPAC, name for the monomer used in its synthesis?
a)
b)
c)
d)
e)
trans-1,2-dichloroethene
cis-1,2-dichlorothene
cis-1,1-dichloroethane
trans-1,1-dichloroethane
none of the names (a-d) are the correct IUPAC name for the monomer
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 3
Use the information shown below to answer the next seven (7) questions.
At 227oC, 1,3-butadiene gas converts to cyclobutene gas.
The values for -d[1,3-butadiene]/dt are shown below.
time (s)
600
1200
1800
2400
3000
[1,3-butadiene] (M)
0.0148
0.0131
0.0118
0.0107
0.0098
15. (3) Calculate the initial concentration of 1,3-butadiene and the rate constant, k, for
this process.
k
[1,3-butadiene]0
a)
b)
c)
d)
e)
1.33 x 10-3 M-1 s-1
1.33 x 10-3 s-1
1.43 x 10-2 M-1s-1
1.43 x 10-2 s-1
none of these (a-d)
0.0165 M
0.0168 M
0.0170 M
0.0165 M
16. (2) How long will it take for the concentration of 1,3-butadiene to go to one-half of
its original concentration?
a) 1.14 hr
b) 1.48 hr
c) 2.28 hr
d) 2.96 hr
e) none of these (a-d)
17. (2) If the activation energy of the forward reaction at 227 oC is 52 kJ and the
activation energy of the reverse reaction is 126 kJ, what is the enthalpy change for
this one-step reaction?
a) 74 kJ
b) -74 kJ
c) 52 kJ
d) -52 kJ
e) -183 kJ
18. (3) How will the rate constant of the forward reaction change when the reaction is
run at room temperature, 25 oC, instead of at 227 oC?
a)
b)
c)
d)
e)
rate constant will increase by a factor of about 5000
rate constant will increase by a factor of about 500
rate constant will decrease by a factor of about 500
rate constant will decrease by a factor of about 5000
none of these (a-d)
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 4
19. (2) Which of the following statements is true about this reaction?
a)
b)
c)
d)
1,3-butadiene can exhibit geometric isomerism.
Cyclobutene can exhibit geometric isomerism.
2-butyne is a structural isomer of both 1,3-butadiene and cyclobutene.
Cyclobutene will be more stable than cyclobutane because the difference in
hybridization leads to less bond strain.
e) The reaction will be endothermic, based on the bonds broken and formed.
20. (2) What is the expected NMR signal from 1,3-butadiene?
a)
b)
c)
d)
e)
1 doublet and 1 triplet
2 doublets and 1 triplet
1 doublet and 1 quartet
2 doublets and 1 quartet
2 doublets
21. (2) What is the expected NMR signal from cyclobutene?
a)
b)
c)
d)
e)
1 doublet and 1 triplet
2 doublets and 1 triplet
1 doublet and 1 quartet
2 doublets and 1 quartet
2 doublets
22. (2) Shown below is the structure of the steroid, aldesterone.
O
HO
O
OH
O
Which of the following functional groups is not found in aldesterone?
a) 1o alcohol
d) ketone
b) 2o alcohol
e) carboxylic acid
c) aldehyde
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 5
23. (2) Under certain experimental conditions, the reaction
H2O2 + 3I- + 2 H+  I3- + 2 H2O
is found to be first order in H2O2, I- and H+
Which one(s) of the following proposed mechanisms can explain the rate law and
stoichiometry?
Mechanism 1
H+ + I-  HI
HI + H2O2  H2O + HOI
HOI + I-  OH- + I2
I- + I2  I3H+ + OH-  H2O
rapid equilibrium
slow
fast
fast
fast
Mechanism 1
H2O2 + I-  H2O + OIOI- + H+  HOI
HOI + I-  I2 + OHI- + I2  I3H+ + OH-  H2O
slow
fast
fast
fast
fast
Mechanism 3
H2O2 + H+  H3O2+
H3O2+ + I-  H2O + HOI
HOI + I-  OH- + I2
I2 + I-  I3H+ + OH-  H2O
rapid equilibrium
slow
fast
fast
fast
Mechanism 4
H2O2 + I-  H2O + OIOI- + I-  I2 + O2O2- + 2 H+  H2O
I2 + I-  I3-
rapid equilibrium
slow
fast
fast
a) Mechanism 1 only
b) Mechanism 2 only
c) Mechanism 3 only
d) Mechanism 4 only
e) More than one of these mechanisms correctly explains the rate law and
stoichiometry
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 6
24. (2) What are the reactants in the condensation reaction which produces
isopropylpentanoate and water?
OH
OH
OH
III
II
I
O
O
OH
OH
O
a) I and V
VI
V
IV
b) II and V
c) III and VI d) III and IV e) II and IV
25. (2) What are the products when the following compound is hydrolyzed?
O
N
I.
II.
III.
IV.
V.
VI.
VII.
2-methylbutanoic acid
2-methylpropanoic acid
3-methylbutanoic acid
ethylamine
dimethylamine
ethylmethylamine
water
a) I and IV
d) II, V and VII
b) II and V
e) III, VI and VII
c) III and VI
26. (3) Which of the following compounds is named incorrectly?
II
I
O
CH3 CH2 NH
IV
III
CH(CH3)2
O
CH3
CH2 CH2 CHO
O
ethyl ethanoate
a) I
ethylisopropylamine
ethyl propyl ether
butanal
b) II c) III d) IV e) none of them (I - IV) are named incorrectly
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 7
27. (3) Cyclohexanone and phenol can undergo a nucleophilic addition reaction in the
presence of an acid catalyst. Identify which of the species, shown below, exists at
each of the marked positions in the reaction coordinate..
O
OH
H
+
+
product
H
HO
HO
OH
O
OH
O
II
I
IV
III
H
OH
HO
V
HO
O
O
VI
VII
B
P.E.
A
C
D
reaction coordinate
a)
b)
c)
d)
e)
A
B
C
D
III
IV
V
IV
V
none of the above
III
none of the above
IV
none of the above
VII
I
VII
I
VII
VI
VI
VI
II
II
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 8
28. (3) The correct IUPAC name for this compound is:
a)
b)
c)
d)
e)
4,6-dimethyl-5-propenyl-1-heptene
trans-5-isopropyl-4-methyl-1,6-octadiene
trans-5-isopropyl-4-methyl-2,7-octyne
trans-4-isopropyl-5-methyl-2,7-dioctene
cis-5-isopropyl-4-methyl-1,6-octadiene
Use the compounds shown below to answer the next three (3) questions.
III
II
I
V
IV
29. (2) Which of these compounds are structural isomers of each other?
a) I and II
b) I, III and IV
c) I and V
d) IV and V
e) none of them
30. (2) Which of these compounds can exhibit geometric isomerism?
a) I and III
b) III, IV and V
c) I, III and IV
d) II and IV e) none of them
31. (2) Which of these compounds will have 3 peaks in its NMR spectrum?
a) I
b) II c) III d) IV e) V
32. (2) A compound with the formula C5H10O is completely oxidized to give a product
with the formula C5H10O2. The reactant could be:
a) 1-pentanol
d) 2-methyl-1-butanol
b) 3-pentanone
e) pentanal
c) 3-methyl-2-butanone
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 9
33. (3) Identify the three functional groups whose boiling points are plotted below as a
function of molecular weight.
III
II
200
I
boiling point (o C)
50
-50
10
5
# carbons
I
ethers
alkanes
ketones
1o amines
aldehydes
a)
b)
c)
d)
e)
II
alcohols
esters
ethers
2o amines
1o alcohols
III
esters
2o amines
alkanes
3oamines
1o amines
For the following four (4) questions, identify the missing major product or reactant.
34. (2)
1-butyne + HBr (excess)
a)
Br
b)
c)
d)
Br
Br
e)
Br
Br
Br
Br
Br
35. (2)
OH
+
H , dry
product
a)
b)
c)
d)
e)
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 10
36. (2)
Cl
reactant +
H2 (g)
Pt
Cl
a)
b)
c)
d)
e)
1,2-dichloro-1-cyclopentene
3,3-dichloro-1-cyclopentene
trans- 3,4-dichloro-1-cyclopentene
cis -3,4-dichloro-1-cyclopentene
none of the reactants (a-d) will give this product
37. (2)
H
+
+ H2 O
OH
c)
b)
a)
OH
OH
OH
OH
d)
e)
38. (3) Shown below is a representation of the NMR spectrum of 3,3-dimethyl-2-butanol:
What is wrong with this idealized spectrum?
a)
b)
c)
d)
e)
nothing is wrong with this spectrum
peak b is too small
peak c should be a triplet
there are too many peaks
there are too few peaks
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 11
39. (3) Shown below is a representation of the NMR spectrum of diisopropyl ether:
What is wrong with this idealized spectrum?
a)
b)
c)
d)
e)
nothing is wrong with this spectrum
peak b is too small
peak a should be a triplet
there are too many peaks
there are too few peaks
Some of the structural isomers with the formula C5H10O are listed. Identify the idealized
spectrum of each of these compounds.
40. (2) 3-pentanone
41. (2) 3-methyl-2-butanone
42. (2) 2-pentanone
43. (2) 1-methylcyclobutanol
44. (2) 2,2-dimethylpropanal
45. (2) 2-methyl-2-butanol
e) none of these
CHEMISTRY 204
HOUR EXAM III
Spring 2006
page 12