State College of Florida Nitration of Benzaldehyde Lab Report

Nitration of Benzaldehyde prelabPurpose: to target the compound, 3-nitro-benzaldehyde, to synthesize. And to examine the
product and determine substitution pattern.
Chemicals:
Benzaldehyde
Formula: C₇H₆O
• Molecular Weight: 106.12 g/mol
• Density: 1.04 g/cm³
• Melting Point: -26°C
• Boiling Point: 178.1°C
• Dangers: Can causes nose and skin irritation and shortness of breath.
• Solubility: water
• References: https://pubchem.ncbi.nlm.nih.gov/compound/Benzaldehyde
Diethyl ether
Formula: (C2H5)2O
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Molecular Weight: 74.12 g/mol
Density: 713 kg/m³
Melting Point: -116.3°C
Boiling Point: 34.6°C
Dangers: Can cause unconsciousness and even death if exposed at a high level.
Solubility: slightly solubility in water. Soluble in Ethers and Epoxides.
References:https://pubchem.ncbi.nlm.nih.gov/compound/Ether#:~:text=Diethyl%
20ether%20is%20an%20ether,ChEBI
Nitric Acid
Formula: HNO₃
• Molecular Weight: 63.01 g/mol
• Density: 1.51 g/cm³
• Melting Point: -42°C
• Boiling Point: 83°C
• Dangers: can cause irritation to the skin, eyes, and mucous membrane. And
causes pneumonitis, bronchitis, dental erosion, and delayed pulmonary edema.
• Solubility: Soluble in water.
• References: https://pubchem.ncbi.nlm.nih.gov/compound/Nitricacid#:~:text=Nitric%20acid%20is%20a%20nitrogen,conjugate%20acid%20of%2
0a%20nitrate.
Sulfuric Acid
Formula: H₂SO₄
• Molecular Weight: 98.079 g/mol
• Density: 1.83 g/cm³
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Melting Point: 10°C
Boiling Point: 337°C
Dangers: can cause irritation and burning to the skin and eyes
Solubility: Soluble in water.
References: https://pubchem.ncbi.nlm.nih.gov/compound/Sulfuric-acid
3-nitrobenzaldehyde
Formula: C7H5NO3
• Molecular Weight: 151.121 g·mol−1
• Density: 1.338g/cm3
• Melting Point: 58.5°C
• Boiling Point: 164 °C
• Dangers: can cause gastrointestinal irritation with vomiting, diarrhea, and nausea.
• Solubility: Soluble in ethanol, acetone
• References: https://pubchem.ncbi.nlm.nih.gov/compound/3-Nitrobenzaldehyde
Apparatus:
Materials:
1. Round bottom flask
2. Stir Plate
3. Heater mantle
4. Condenser
5. Nitrogen Gas
6. Separatory funnel
7. TLC
8. NMR
9. FTIR
Procedure
1. Start Virtual ChemLab and select Benzene
Nitration – 1 from the list of assignments on
the whiteboard.
2. After entering the synthesis laboratory, use
the available reagents on the stockroom
shelf and identify the appropriate starting
materials required to synthesize the target
compound and add them to the round
bottom flask. Select the appropriate solvent
and drag the flask to the Stir Plate on the lab
bench.
3. The round bottom flask containing the
starting materials should now be on the stir
plate, and the contents of the flask should be
visible on the chalkboard.
4. From the group of reagents found on the lab
bench, select the correct reagent to
synthesize the target compound and add it
to the flask on the stir plate.
5. Now attach the heater, condenser, and N2
gas to the round bottom flask so the reaction
mixture can be heated.
6. Take an initial TLC of the reaction mixture
and save it to your lab notebook.
7. Start the reaction by clicking on the Stir
button on the front of the stir plate. You
should be able to observe the reaction
mixture stirring in the flask. Monitor the
progress of the reaction using TLC
measurements as necessary until the product
has formed and the starting materials have
been consumed. You can advance the
Observation
laboratory time using the clock on the wall.
With the electronic lab book open (click on
the lab book on the stockroom counter), you
can also save your TLC plates by clicking
Save on the TLC window.
8. Reaction time should be around 4 hours.
9. Take a final TLC measurement of the
reaction to make sure all the starting
material is consumed and save it to your lab
book.
10. When the reaction is complete, “work up”
your reaction by first dragging and dropping
the separatory funnel on the flask and then
adding H2O to the funnel.
11. Extract the organic layer in the funnel by
clicking on the top layer and dragging it to
the cork ring on the lab bench. Your target
compound should now be in this flask.
12. Perform an IR of your product by clicking
on the IR spectrometer and dragging it to
the flask.
13. Perform a 1H NMR of your product by
clicking on the NMR spectrometer and
dragging it to the flask. Save your 1H NMR
to your lab book.
14. Perform a 13 C NMR of your product by
clicking on the NMR spectrometer and
dragging it to the flask. Save your 13C
NMR to your lab book.
Pre Laboratory Questions
1. Explain why the nitration occurs in the meta position.
−”#$ is an electron withdrawing group, which will decrease the density of a electron at ortho
and para position of an aromatic ring. Because of this, the electrophile approach meta position.
2. Why is it important to keep the reaction mixture cold?
It is important because it is exothermic. Exothermic reactions will release heat, making the
surrounding feel hot.
3. What is the function of the sulfuric acid?
&ℎ( )*+,-./+ /) #! 0$” is that it’s a proton source and acts as a dehydrating agent. Sulfuric
acid is used to help nitronium ions to form.
Nitration of Benzaldehyde
Virtual Lab
Purpose:
For this assignment, the target compound that you should synthesize is 3-nitrobenzaldehyde. This is an electrophilic aromatic substitution reaction. Examine the product
carefully and determine the substitution pattern. Which group will already be present in the
substrate? Keep in mind the mechanism and how that will control the selectivity of the process.
Materials:
1. Chemicals:
a. Benzaldehyde
b. Diethyl ether
c. Nitric Acid
d. Sulfuric Acid
e. 3-nitrobenzaldehyde
2. Apparatus:
a. Make sure to insert a picture of your apparatus that you set up
Procedure:
1. Start Virtual ChemLab and select Benzene Nitration – 1 from the list of assignments on
the whiteboard.
2. After entering the synthesis laboratory, use the available reagents on the stockroom
shelf and identify the appropriate starting materials required to synthesize the target
compound and add them to the round bottom flask. Select the appropriate solvent and
drag the flask to the Stir Plate on the lab bench.
3. The round bottom flask containing the starting materials should now be on the stir
plate, and the contents of the flask should be visible on the chalkboard.
4. From the group of reagents found on the lab bench, select the correct reagent to
synthesize the target compound and add it to the flask on the stir plate.
5. Now attach the heater, condenser, and N2 gas to the round bottom flask so the reaction
mixture can be heated.
6. Take an initial TLC of the reaction mixture and save it to your lab notebook.
7. Start the reaction by clicking on the Stir button on the front of the stir plate. You should
be able to observe the reaction mixture stirring in the flask. Monitor the progress of the
reaction using TLC measurements as necessary until the product has formed and the
starting materials have been consumed. You can advance the laboratory time using the
clock on the wall. With the electronic lab book open (click on the lab book on the
stockroom counter), you can also save your TLC plates by clicking Save on the TLC
window.
8. Reaction time should be around 4 hours.
9. Take a final TLC measurement of the reaction to make sure all the starting material is
consumed and save it to your lab book.
10. When the reaction is complete, “work up” your reaction by first dragging and dropping
the separatory funnel on the flask and then adding H2O to the funnel.
11. Extract the organic layer in the funnel by clicking on the top layer and dragging it to the
cork ring on the lab bench. Your target compound should now be in this flask.
12. Perform an IR of your product by clicking on the IR spectrometer and dragging it to the
flask.
13. Perform a 1H NMR of your product by clicking on the NMR spectrometer and dragging it
to the flask. Save your 1H NMR to your lab book.
14. Perform a 13 C NMR of your product by clicking on the NMR spectrometer and dragging
it to the flask. Save your 13C NMR to your lab book.
Pre Laboratory Questions
1. Explain why the nitration occurs in the meta position.
2. Why is it important to keep the reaction mixture cold?
3. What is the function of the sulfuric acid?
Post Laboratory Questions
1. Why is the product less reactive toward nitration than the starting material?
2. Predict the most favorable position of nitration for the following compound. Explain your
answer clearly.
O
O
3. Look at the 1HNMR of the product with the region of 7.5-9.0 ppm blown up for better view.
Specifically, in terms of the splitting patterns in the 1HNMR,indicate why you know the
product is 3-nitrobenzaldehyde.
4. If a student started with 4.53 mL of benzaldehyde and an excess of nitric acid, calculate the
theoretical yield of the product. (density of benzaldehyde is 1.044 g/mL)
How to Write up
Your Full-Laboratory Report
CHM 2210/2211
PRELAB:
✓ This is to be completed by the Due Date in Canvas and placed in the drop-box. File format will be pdf.
✓ Pre-lab includes this whole page except observations and conclusions.
✓ Failure to have your pre-lab written up before lab may result in a zero for the lab.
Purpose: (Short but complete)
Equations: Mathematical and or chemical (if chemical make sure they are balanced)
Materials:
Apparatus: Any new item used should be described and shown. Any set-up should be shown and
labeled.
Chemicals: (All chemicals used or produced in the experiment)
Examples:
ORGANIC COMPOUNDS
INORGANIC COMPOUNDS
Chemical Name: Biphenyl
Chemical Name: Sodium Hydroxide
Formula: C12H10
Formula: NaOH
Structure:
Molecular Weight: 40.0 g/mol
Solubility: H2O
Danger: Caustic, Burns, irritant
Molecular Weight (MW): 154.21 g/mol)
Boiling Point (bp): 255.9°C
Melting Point (mp): 69-71°C
Density (d): 0.8660 g/ml
Solubility (sol.): al, eth, bz
Refractive Index (n): NA
Danger and Precautions: none to note
Reference: The Merck Index, 10th Ed., Merck &Co., 1984
Questions:
All prelab questions
Procedure:
Make 2 Columns: Write up your procedure in the left column BEFORE coming to lab.
Method
Observations
1. Weigh out 0.5 g NaCl
2.
Etc.
(Use numbered steps to tell everything you are
going to do. You should be able to hand this to a
fellow student who has not read the laboratory and
he/she should be able to follow it. This must be
done prior to the laboratory meeting.
1. mass = 0.4735 g NaCl
2.
Etc.
(Under observations you should record everything
you see: color, temperature, times, etc. Also, put
here anything you did different or anything that
went wrong. Make it legible
***Anytime you make a mistake in your laboratory notebook use a single line to cross out the mistake. Do not
leave any empty space. Mark empty space with a large X.
Note: If your prelab is incomplete you may be asked to leave the laboratory. The result will be a zero for that
laboratory experiment. If you continually make the same errors on your prelab, the points taken off will increase
with each subsequent laboratory repeating those same errors. Examples of this are: leaving off units, omitting
specific properties, certain sections incomplete, etc.
Inlab: This is your observations and data. These go under observations in your procedure. Failure to have
observations will result in points deducted from your procedure points.
Post Lab:
Data: In an easy to read tabulated form (i.e. tables with headings). These would be after the procedure.
Graphs: If necessary
Post lab Questions: Do all the post lab questions assigned.
Conclusions: Summary of the laboratory experiment which includes anything that might have gone
wrong or anything you did different from the original procedure.
Tips for writing a good lab report
1. Please use the following guidelines for your report:
a. Font 12
b. Margins
i. 1 inch all around.
c. Spacing 1.5
d. Font:
i. Calibri
ii. Tacoma
iii. Times New Roman
2. NEVER write anything in the data tables provided with the lab procedure until you have completed the
experiment. Raw data belongs in the lab book first. Transfer the final data to the data tables after all your
work is done.
3. Be complete in your descriptions of equipment setups and observations. The Lab Practical Exam
requires a thorough knowledge of each lab procedure. Your best study source for the practical is your
lab report. If you are not thorough you will forget what you wrote when you read it again. Remember,
any student should be able to repeat the experiment by referring to your lab report.
4. Many answers to the pre and post-lab questions can be found in the procedure itself.