Description
9/29/2021 5:06:26 PM Page 1 / 1
Analysis Report
S343 Elimination Lab Sample
Sample Name
Sample ID
Data Filename
Method Filename
Batch Filename
Vial #
Injection Volume
Date Acquired
Date Processed
: Group 6_B
: base
: Group 6_B_base_012.gcd
: S343 Elim GC Lab.gcm
: Elimination Lab.gcb
: 37
: 1 uL
: 9/28/2021 7:30:32 PM
: 9/28/2021 7:37:35 PM
Sample Type
: Unknown
Acquired by
Processed by
: orglab
: orglab
Chromatogram
uV
5.200
SFID1
30000000
1
2
4
5
6.238
5.868
4.787
4.315
3
4.512
0
2.453
1.654
1.823
10000000
2.044
20000000
6
min
Peak Data Table
SFID1
Peak# Ret. Time
1
1.654
2
1.823
3
2.044
4
2.453
5
4.315
6
4.512
7
4.787
8
5.200
9
5.868
10
6.238
Total
Area
2601
15192615
17913308
408329
1331782
96086
214069
241238708
855268
2482
277255248
Height
745
4066584
4620637
104469
255170
18362
25708
37192822
120296
344
46405138
Conc.
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
C:\LabSolutions\Data\Project1\J343 FA21\Rachel Lab 22900\Group 6_B_base_012.gcd
9/29/2021 5:05:42 PM Page 1 / 1
Analysis Report
S343 Elimination Lab Sample
Sample Name
Sample ID
Data Filename
Method Filename
Batch Filename
Vial #
Injection Volume
Date Acquired
Date Processed
: Group 6_A
: acid
: Group 6_A_acid_007.gcd
: S343 Elim GC Lab.gcm
: Elimination Lab.gcb
: 32
: 1 uL
: 9/28/2021 6:28:35 PM
: 9/28/2021 6:35:40 PM
Sample Type
: Unknown
Acquired by
Processed by
: orglab
: orglab
Chromatogram
uV
SFID1
5.204
40000000
30000000
1
2
3
4
5
6.239
5.869
4.787
4.513
4.309
3.649
3.761
3.023
0
2.592
1.824
10000000
2.044
20000000
6
min
Peak Data Table
SFID1
Peak# Ret. Time
1
1.824
2
2.044
3
2.592
4
3.023
5
3.649
6
3.761
7
4.309
8
4.513
9
4.787
10
5.204
11
5.869
12
6.239
Total
Area
1673492
16004745
2067
2836
11359
166044
63287
104431
231764
261966841
925859
2506
281155232
Height
449860
4124712
444
533
2889
34996
9943
19760
27843
39866383
129942
363
44667668
Conc.
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
C:\LabSolutions\Data\Project1\J343 FA21\Rachel Lab 22900\Group 6_A_acid_007.gcd
Post-Lab Assignment for Elimination (32 points)
Type your answers to the following questions. Bring a hard copy to lab the following week, and upload your
document to canvas.
1. Attach a GC trace (to the hard copy only) and fill in the table below. (4 points)
entry conditions
isomer
area
boiling point retention time
(lit value)
1
acidic
2
2
3
3
basic
see entry 1
4
see entry 2
2. If the elimination of this alkyl chloride were completely random, what would you expect the product
distribution to be? Explain how you came to this conclusion. (Consider the statistically random abstraction
of all B-protons: how many would lead to formation of each product?) (4pts)
3. What was the product distribution in the acid catalyzed reaction? Report your product distribution as an X:Y
ratio, where one of the numbers is 1. For example, if you found the area of one isomer was 100, while the
area of the other was 50, you would report a 2:1 ratio. Use data summarized in the table above to quantify
this product distribution. How does the product distribution compare to a random elimination? Is the
Zaitsev or Hofmann product favored? (4 points)
4. Propose an arrow mechanism for the acid-catalyzed reaction. (Use ChemDraw.) How is your mechanism
consistent with your product distribution data? (4 pts)
5. What was the product distribution in the base catalyzed reaction? Use data to quantify this product
distribution and report it as you did in problem 3. How does the product distribution compare to a random
elimination? Is the Zaitsev or Hofmann product favored? (4 points)
6. Propose an arrow mechanism for the base-catalyzed reaction. (Use ChemDraw.) How is your mechanism
consistent with your product distribution data? (4 pts)
7. Compare the product distributions in the two mechanisms. Why are they different? (+4)
Question: Is the Zaitsev or Hofmann product favored under acid or base elimination conditions? How can the
outcome be explained by the mechanism?
Procedure: You will work with a partner to accomplish the following two elimination reactions. Both partners
must stay in the lab until the entire project is done, so consider proper teamwork principles to accomplish an
overall efficient use of time.
Elimination of 2-methyl-2-butanol under acidic conditions: Place 2.4 grams of 2-methyl-2-butanol in a 25 ml
round bottom flask with a stir bar. Carefully add 15 mL of 6 M sulfuric acid to the flask. Add an air condenser to
the flask and complete the fractional distillation apparatus shown in Figure 12.17 (except the air condenser will
replace the fractionation column.) Place the receiving flask in an ice water bath. Gently heat the reaction in a
water bath at 85-90 °C. Collect the distillate that comes over below 45 °C. Make a GC sample as directed below.
Elimination of 2-chloro-2-methylbutane under basic conditions: Put 23 mL of basic 1-propanol solution in a 50
mL round bottom flask. (There are 3.0 g of KOH per 23 mL of the solution.) Slowly pour 3.0 mL of 2-chloro-2-
methylbutane into the basic solution. Add an air condenser to the flask and complete the fractional distillation
apparatus shown in Figure 12.17 (except the air condenser will replace the fractionation column.) Use a tared,
25 mL round bottom flask in ice as a collecting flask. Heat and stir the reaction for one hour in a 75-80 °C water
bath, monitoring the temperature closely so that it does not exceed 80 °C during the reflux period. Add
additional ice to the receiving flask as necessary. A white precipitate will form in the reaction flask. After one
hour, increase the water bath temperature to 90-95 °C and distill the reaction mixture. Collect all the distillate
boiling below 45 °C. Make a GC sample as directed below.
Gas Chromatography: Prepare a GC sample for the autosampler. (You will leave your sample to be analyzed by
an automated GC sampler.)
1. Obtain a GC vial and cap.
2. Place 2-3 drops of your distillate in the vial, then add heptane until the vial is half full.
3. screw on the cap, making sure it is on TIGHTLY!
4. Your Al will run your GC for you, so ask them how they would like the vial labeled. One option is to label
the vial with a Sharpie with your three initials, the day (R or F) and the time (1:20 or 2:30) of your lab.
For example: LCB, R 12:15
5. Place in the GC vial collection box.
6. Be sure to have your Al explain how you will receive the data.
GC parameters:
Column Type: HP-5 5% Phenylmethyl Siloxane
Oven: 65 °C, isothermal for 5 min
He flow: Flow rate 7.5 mL/min
Injector: Auto-injection, volume 1.0 L
Heater 150 °C
FID Detector: Heater 250 °C
Purchase answer to see full
attachment