Long Beach State University Organic Chemistry Project

Student ID hereLab section code
Your Name Here
Mastery Project Template
Instructions for Using Template
1. Do NOT resize this document in any way. Do not change margins or page size.
2. ANY highlighted text in yellow in a box should be replaced with your relevant
information. This includes your name, the practical version, student ID, answers, etc.
3. Individual answers may be as long or as short as needed, but your response for each
experiment must not exceed 2 pages (including mechanism and tables).
4. You will convert this template into a PDF once you are ready to submit it.
5. Failure to follow these instructions will result in no points given for that question.
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Copy the following academic honesty statement BY HAND (on paper or using note-taking
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Chem 51LB.
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Cyclohexyl Halide Elimination
Mechanism
Insert your mechanism drawing here. You may choose to provide a ChemDraw image or a hand
drawn mechanism. Make sure the image is clear.
Results
Create your results table(s) here. Tables should be single-spaced.
Your answers must NOT exceed 2 pages per experiment.
Discussion Question 1
Add your response here.
Discussion Question 2
Add your response here.
Your answers must NOT exceed 2 pages per experiment.
Your answers must NOT exceed 2 pages per experiment.
Project: Study of Reaction Condition Variations in the Elimination
Reaction of Cyclohexyl Halides
Elimination reactions are one of a few fundamental basic reactions in organic chemistry.
These reactions involve the loss of two substituents and the creation of a double bond.
There are two different types of elimination reaction mechanisms you are currently
familiar with – E1 and E2 – each with a specific set of conditions that favors it.
In this experiment, you will study several elimination reactions involving different
cyclohexyl halides, in turn analyzing gas chromatography data to understand reaction
kinetics. After inspecting the data obtained, you will develop chemical explanations to
rationalize the results that were obtained.
Reaction Variation
X
Temperature
Base
1a
Br
Reflux
2 mL
1b
Cl
Reflux
2 mL
1c
I
Reflux
2 mL
1d
Br
Reflux
1 mL
1e
Br
Room temperature
2 mL
In your submission for this assignment, you will address the following components:
For a B-level grade:
Results: Summarize the reaction conversion data in a complete and neat table.
Discussion 1: Based on this data, which variable seems to impact the reaction rate
most heavily? Use chemical reasoning and data to support your claim.
For an A-level grade, address all of the components above AND:
Mechanism: Draw the arrow-pushing mechanism for ONE elimination reaction (1a-1e).
Discussion 2: Based on this data, which variation on the reaction conditions provides
evidence for the type of elimination mechanism that this reaction follows? Use chemical
reasoning and data to support your claim.
1
Instructions for Calculating Percent Conversion from Gas
Chromatograms
In order to evaluate the kinetics of the elimination reactions, you will calculate a value
called “percent conversion”. Percent conversion refers to the amount of starting material
that is consumed during a reaction, regardless of what product(s) it forms. It is
calculated by comparing the amount of starting material at the end of a reaction to the
sum of the amounts of starting material and the product(s) made.
For example, in the gas chromatogram below, the starting material of the reaction has a
retention time of 5.8 minutes and the product has a retention time of 13.3 minutes:
Starting
material
Product
Peaks
Retention Time (min)
Peak Area
Peak Width
Peak Height
Peak 1
5.8
2410
6
803.33333
Peak 2
13.3
458
4
229
The area under a peak in gas chromatograms correlates to the amount of a compound
in the sample, which means we can use it to calculate conversion (Eq. 1).
𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑐𝑜𝑛𝑣𝑒𝑟𝑠𝑖𝑜𝑛 =
( )
( )
( )
( )
× 100
(1)
By inputting the appropriate values, we obtain the following:
𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑐𝑜𝑛𝑣𝑒𝑟𝑠𝑖𝑜𝑛 =
458
× 100
458 + 2410
Therefore, the percent conversion for the reaction shown is 16%.
2