CHML212
Exp. 13: Calculation, Chromatographic, and Spectral Applications in the Laboratory
IN-LAB ASSIGNMENT: (EACH STUDENT will show full calculations listed below for Reaction 1 and Reaction 2 in his/her
laboratory notebook in a well organized manner. Full calculation must be shown to receive full credit. Final answer must be
clearly indicated with a circle. Yellow carbon copies will be submitted for grading along with Post-Lab assignment.) …..max
score = 20 pts.
Reaction 1: Acid Catalyzed Dehydration of an Alcohol
OH
H2SO4(cat)
2-methyl-2-pentanol
MW: 102.17 g/mol
d: 0.835 g/mL
cost: $67.20/12 mL
Amount used: 2.0 mL
sulfuric acid
cost: $25.00/500 mL
Amount used: 0.5 mL
+ H2O + H2SO4
2-methyl-1-pentene
MW: 84.16 g/mol
d: 0.682 g/mL
cost: $129.50/25 mL
Product mass: 1.20 g
Calculations:
a. Theoretical yield based on alcohol
b. Percent yield for reaction
c. Atom economy
d. Experimental atom economy
e. “E” product
f. Cost per synthesis
g. Cost per gram
h. Cost per 25 mL bottle
i. Adjusted area percent of 2-methyl-1-pentene
j. Adjusted area percent of 2-methyl-2-pentanol
Reaction #2: Ester Synthesis
O
O
+
OH
HO
acetic acid
MW: 60.05 g/mol
d: 1.049 g/mL
cost: $33.10/500 mL
Amount used: 2.0 mL
isoamyl alcohol
MW: 88.15 g/mol
d: 0.809 g/mL
cost: $53.60/100 mL
Amount used: 2.0 mL
Calculations:
a. Theoretical yield based on alcohol
b. Theoretical yield based on acid
c. Percent yield for reaction
d. Atom economy
e. Experimental atom economy
f. “E” product
g. Cost per synthesis
h. Cost per gram
i. Cost per 100 mL bottle
j. Adjusted area percent of isoamyl acetate
k. Adjusted area percent of isoamyl alcohol
H2SO4(cat)
sulfuric acid
cost: $25.00/500 mL
Amount used: 0.5 mL
+ H2O + H2SO4
O
isoamyl acetate
MW: 130.18 g/mol
d: 0.876 g/mL
cost: $64.10/100 mL
Product mass: 2.00 g
POST-LAB ASSIGNMENT: (EACH LAB GROUP will submit one copy of a typewritten, paragraph style report addressing
all of the points listed below based on REACTION 2 only. All tables for BOTH reactions must be completed and copied into
the document. Must be written using PAST TENSE, PASSIVE VOICE.) …..max score = 80 pts.
Reaction 1: Acid Catalyzed Dehydration of an Alcohol
OH
H2SO4(cat)
2-methyl-2-pentanol
MW: 102.17 g/mol
d: 0.835 g/mL
cost: $67.20/12 mL
Amount used: 2.0 mL
sulfuric acid
cost: $25.00/500 mL
Amount used: 0.5 mL
2-methyl-1-pentene
MW: 84.16 g/mol
d: 0.682 g/mL
cost: $129.50/25 mL
Product mass: 1.20 g
Table 13.1 Experimental Results
Theoretical Yield (g)
Actual Yield (g)
Percent Yield
Table 13.2 Green Chemistry Results
Atom Economy (%)
Experimental Atom Economy (%)
“E” product
Cost per Synthesis ($)
Cost per Gram ($/g)
Cost per 25 mL bottle
Table 13.3 GC Results
GC Retention Times (min)
Standard
Sample
2.533
3.054
4.324
Compound
methanol
2-methyl-1-pentene
2-methyl-2-pentanol
Area
Percent
Adjusted
Area Percent
X
Table 13.4 1H NMR Spectral Analysis
1a
OH
4
5
2
4
5
1b
H#
1a
1b
2 (OH)
3
4
5

(ppm)
2.04
2
1a
3
Int.
1
Mult.
s
H#
1a
1b
2
3
4
5
1b
3

(ppm)
4.66
Int.
4.70
X
1
Mult.
1
X
s
s
X
Table 13.5 13C NMR Spectral Analysis
1a
OH
4
5
2
4
3
5
1b
C#
2
1a

(ppm)
1a
1b
2
3
4
5
1b
3

(ppm)
22.34
C#
1a
1b
2
3
4
5
20.91
Table 13.6 IR Spectral Analysis
Functional
Group
Base
Values
(cm-1)
OH stretch
C-O stretch
sp3 CH stretch
sp2 CH stretch
C=C stretch
3200-3600
1000-1300
2800-3000
3000-3100
1600-1680
2-methyl-2pentanol
Frequency
(cm-1)
2-methyl-1pentene
Frequency
(cm-1)
X
X
X
X
Table 13.7 Mass Spectral Analysis
OH
m/z
Cation
fragment
formula
Structure
m/z
Cation
fragment
formula
Structure
102
(M+)
Molecular Ion
84
(M+)
Molecular Ion
59
(base)
Cationic Fragment
69
(base)
Cationic Fragment
Reaction #2: Ester Synthesis
O
O
H2SO4(cat)
OH
HO
isoamyl alcoholl
MW: 88.15 g/mol
d: 0.809 g/mL
cost: $53.60/100 mL
Amount used: 2.0 mL
acetic acid
MW: 60.05 g/mol
d: 1.049 g/mL
cost: $33.10/500 mL
Amount used: 2.0 mL
O
sulfuric acid
cost: $25.00/500 mL
Amount used: 0.5 mL
isoamyl acetate
MW: 130.18 g/mol
d: 0.876 g/mL
cost: $64.10/100 mL
Product mass: 2.00 g
Table 13.8 Experimental Results
Theoretical Yield (g)
Actual Yield (g)
Percent Yield
Table 13.9 Green Chemistry Results
Atom Economy (%)
Experimental Atom Economy (%)
“E” product
Cost per Synthesis ($)
Cost per Gram ($/g)
Cost per 100 mL bottle
Table 13.10 GC Results
GC Retention Times (min)
Standard
Sample
1.890
2.211
2.748
Compound
methanol
Isoamyl alcohol
Isoamyl acetate
Area
Percent
Adjusted
Area Percent
Table 13.11 1H NMR Spectral Analysis
6
6
O
3
3
5
6
H#
1
2 (OH)
3
4
5
6
5
OH
4
6
2

(ppm)
X
1.57
Int.
Mult.
H#
X
1
X
s
1
2
3
4
5
6
O
4
Int.
Mult.
X
X
X
6
O
3
3
5
6
C#
1
2
3
4
5
6
4
OH
2

(ppm)
X
X
5
6
C#
1
2
3
4
5
6
4
1

(ppm)
Table 13.12 13C NMR Spectral Analysis
6
2
O
2

(ppm)
1
Table 13.13 IR Spectral Analysis
Functional
Group
Base
Values
(cm-1)
OH stretch
C-O stretch
sp3 CH stretch
C=O stretch
3200-3600
1000-1300
2800-3000
1700-1725
Isoamyl
alcohol
Frequency
(cm-1)
Isoamyl
acetate
Frequency
(cm-1)
Table 13.14 Mass Spectral Analysis
O
OH
m/z
Cation
fragment
formula
O
Structure
m/z
88
(M+)
Molecular Ion
130
(M+)
70
Cationic Fragment
43
(base)
Cation
fragment
formula
Cation
fragment
structure
Molecular Ion
Cationic Fragment
Discussion (Write 1-2 paragraphs including the following.)







What was the theoretical yield for this reaction? What was the actual yield? What was the calculated percent
yield for this reaction?
What was the atom economy for this reaction? What was the experimental atom economy for this reaction?
Based on these values, propose one specific way the efficiency of this reaction could be improved.
What was the cost per bottle of the product synthesized compared to the manufacturer’s cost? How could the
cost of the student’s product be lowered to make it more marketable as compared to the manufacturers?
What was the adjusted area % for the product based on GC analysis? Does this indicate that the product was pure
or impure? Give names of any compounds which appear in your chromatogram.
How can IR spectroscopy be used to differentiate between the reactant and the product in this experiment? Give
the identity of one type of absorption and how it could be used to determine whether or not the conversion took
place. Include the typical frequency and the actual frequency for this type of bond in your statement.
How can NMR spectroscopy be used to differentiate between the reactant and the product in this experiment?
Give the identity of one type of proton and how it could be used to determine whether or not the conversion took
place. Include the typical chemical shift and the actual chemical shift for this type of proton in your statement.
What was the m/z value of the molecular ion of the product based on mass spectrometry? Does this make sense
based on the molecular weight of the reactant, and the chemistry which took place? Briefly explain.