Organic Chemistry Lab Report

For the reaction part, you can just draw it out and I will insert it online. No need to download the website. Please use the following pdfs for the lab report. I have also included an example of a good report so you can base it on that.

Lab used is the Esterficiation Lab

Data:

*Exact mass of isoamyl alcohol used = 0.881g (0.010mol x 88.15g/mol = 0.881g)

*Exact mass of carboxylic acid = 0.663g (0.011mol x 60.05g/mol = 0.663g)

*Percent yield calculation = 26.69%

0.881g of alcohol x 1mol/ 88.15 g/mol x 1mol/1mol x 130.18 g/mol / 1mol = 1.30g

0.347g / 1.30g x 100 = 26.69%

*Odor of Ester : Banana smell

*Mass of product: 0.347g

1. one C-H stretch, one C-O stretch, and the C=O stretch you found for your FT-IR was from the IR graph attached:

C-H: 2959.10

C=O: 1739.23

C-O: 1055.29

2. Identify any impurity found on FT-IR IF there was any impurity detected

Answer: Water was detected the first time. Second time there was no impurity.

Fischer Esterification of an Ester using a Dean-Stark Apparatus
Objectives:
•
•
•
Synthesize an ester via Fischer esterification using a microscale Dean-Stark
apparatus
Calculate the percent yield
(Optional) If you notice the smell of your ester, identify what you think it smells like
Keep your product for the next lab, when you will:
• Record the ATR FT-IR spectrum of your product
• Identify the C=O stretch, C–O stretch, and C–H stretch peaks on your ester’s FT-IR
• Identify the C–O stretch, O–H stretch, and C–H stretch peaks on a database
spectrum of your alcohol
• Identify the C=O stretch, C–O stretch, O–H stretch, and C–H stretch peaks on a
database spectrum of your carboxylic acid
• Identify any impurities (alcohol, acid, or water) in your ester using FT-IR
spectroscopy
Materials:
•
Reactants
o A carboxylic acid [either acetic acid (60.05 g/mol) or propionic acid (74.08
g/mol)] assigned by your instructor
o An alcohol [either n-propyl (60.10 g/mol), n-amyl (88.15 g/mol) or isoamyl
(88.15 g/mol)] assigned by your instructor
o Concentrated sulfuric acid
o Saturated sodium bicarbonate
o Saturated sodium chloride (brine)
o Anhydrous sodium sulfate
Procedure:
Begin heating your heat bath at a setting of “5” immediately.
1. Add a magnetic stirring bar to your round bottom flask.
2. Your target ester will be assigned at the beginning of lab. Add 0.011 mol of a carboxylic
acid, 0.010 mol of an alcohol, and 4 drops of concentrated sulfuric acid to your reaction
flask.
3. Set up a microscale Dean-Stark apparatus that looks like the one your instructor
demonstrated. Be sure your connectors are not frayed; and your distillation head is
pointing down, not up.
4. Use a cork to seal the distillation head and a 45° angle to aim the distillation head down
slightly.
5. Lower the round bottom flask, connected to its microscale Dean-Stark apparatus, into
the heating bath. Stir and heat for at least 20 minutes. OPTIONAL – when you observe
your Dean-Stark apparatus fill up and two layers form in it (~5 minutes), gently tilt the
apparatus back just enough to pour the top layer, but not the bottom layer, back into
the reaction flask. Repeat every 5 minutes. Whether you tip your Dean-Stark apparatus
or not, the reaction should reflux for 20 minutes.
6. Raise the reaction flask from the heating block and allow it to cool sufficiently (≥10
minutes). Water from the Dean-Stark trap may be added immediately before your
perform step 7., since the reaction has cooled and any reverse reaction will be slow.
7. Perform the first step of this extraction slowly and carefully. The evolution of CO2
bubbles may cause the product to spill if it is rushed. Extract the organic layer with
2×1.0 mL sat. NaHCO3 and then 1×1.0 mL sat. NaCl, sequentially.
8. Dry your product over anhydrous sodium sulfate (Na2SO4) (≥10 minutes).
9. Filter your product, a liquid, to remove sodium sulfate.
10. Determine the mass of your product and save it for analysis by ATR FT-IR and 1H-NMR
tomorrow.
Data:
Exact mass of alcohol used:
Percent Yield Calculation:
Odor of ester (optional):
EXAMPLE OF GOOD REPORT
EXAMPLE OF GOOD REPORT
Overall format – Using the font “Times”, size 12, double-spaced.
Heading (5 pts.)
Includes Title, Date, Name, and uconn e-mail address.
This section should have center-aligned text with a bolded title that is not a duplicate of the lab
handout, but tells me specifically what you did in the lab. The next line should be the date you
turned in your lab report. The last center-aligned line should be your name and the name of all
your lab partners, separated by a comma. Your name should have an * indicating you are the
corresponding author, and your e-mail should appear in the last, left-aligned text line. This
indicates that, out of the names of people who contributed to this lab, questions about the lab
should be directed to you. (Most, if not all labs, will not involve lab partners, but we will still
follow the format).
Reaction (5 pts.)
Use ChemDraw to appropriately show reactant(s) (left side of arrow), reaction conditions
(above/below arrow), and product(s) (right side of arrow).
Purpose (5 pts.)
Summarize what you accomplished and why you did it. Try to focus on the important concept
and/or importance of the chemical reaction (why are alkenes, esters, acids, etc. important to us?).
Try to avoid focusing on “to learn the technique of…”. Identify the purpose of each
characterization technique you performed. 200 word cap, but no word minimum as long as you
complete the above objectives.
Experimental Procedure (15 pts.)
Summarizes the experiment in passive voice so that a student who recently passed organic lab
could repeat the lab. You should not write a lesson on how to do a lab technique. As long as you
are specific about what you did, like “distilled the product that boiled from 136 – 139 °C” or
“recrystallized the product from hexanes”, a trained organic chemist should be able to repeat this.
Limiting reactants should include the exact amount used, in grams or milligrams and moles or
mmol in parentheses after the name of the reactant. Exact amounts should be reported whenever
they were recorded, even if they were not limiting. Crude product and final product should have
exact amounts in grams or milligrams and % yield at that stage in parentheses. Briefly
summarize the results of all characterization you did (melting point, TLC, GC, FT-IR, any
combination) instead of just summarizing “melting point and FT-IR were recorded”.
Discussion (20 pts.)
Start with a one-sentence summary of the results. ___ was synthesized from ___ in a ___ percent
yield. If the lab worked, include one detail about why it worked. If your percent yield was lower
than you expected, summarize what you attribute the loses to and any improvements that could
be made to improve this in future labs. Do not attribute your yield to mistakes. Even though I
understand accidents will happen, it is assumed you are trying not to spill your product and it is
also implied that you would try not to spill it in a repeat of the lab.
EXAMPLE OF GOOD REPORT
EXAMPLE OF GOOD REPORT
100
90
80
3000
2500
2000
Wavenumber cm-1
C:\Users\cob21003\Documents\Bruker\OPUS_8.7.31\DATA\MEAS\ledina ir.0
ledina ir
1500
1055.29
1228.49
1366.72
1739.23
2959.10
3345.13
20
30
Transmittance [%]
40
50
60
70
3500
1000
Instrument type and / or accessory
500
10/25/2022