LABORATORY REPORT
FOR
FUNDAMENTAL ORGANIC CHEMISTRY CHM457
Details of the student:
Name: Ahmad Fawwaz Aiman Bin Aziz
Student’s no: 2019406284
Branch: AS253 2A1
Lecturer’s name: DR FARIDAHANIM BINTI MOHD JAAFAR
Submission date: May 12, 2020
Evaluation criteria:
Experiment Title Objective Apparatus Questions References
3 set up
Details of 0 1-obj. 1 Setup of the 5 Questions Any form of
marks 1-obj. 2 apparatus with references. At least
proper labels 2 references must
be given
1-Ref. 1
1-Ref. 2
Total 0 2 4 12 2
marks
Marks
Given:
Total: /20
CHM457_MARCH-JULY 2020_ONLINE ASSESSMENT_COVID19
Experiment 5
a. Nitration of methyl benzoate.
b. Objectives of the experiment:
i. to synthesize methyl nitrobenzoate from methyl benzoate, concentrated nitric acid,
and concentrated sulfuric acid.
ii. to demonstrate "Electrophilic Aromatic Substitution".
(2 marks)
c. Apparatus & setup:
(4 marks)
d. Questions:
CHM457_MARCH-JULY 2020_ONLINE ASSESSMENT_COVID19
i. Identify nucleophile and electrophile from the experiment?
Nucleophile : Methyl Benzoate
Electrophile : Nitronium ion.
(1 mark)
ii. Show the step-by-step of reactions mechanism on the formation of nitro
methylbenzoate from the reaction.
CHM457_MARCH-JULY 2020_ONLINE ASSESSMENT_COVID19
(4 marks)
iv. As for the nitration experiment, the following parameter are being used/observed
Amount of methylbenzoate used = 5.0 g
Volume of sulphuric and nitric acid used = excess
Isolated product yield = 3.5 g
a) Calculate the percent yield of the reaction
5.0 g
No. of mole methylbenzoate =
136.15 g /mol
= 0.0367 mol
1 mole of methylbenzoate = 1 mole of methyl nitobenzoate
0.0367 mole of methylbenzoate = 0.0367 mole of methyl nitrobenzoate
Mass of methyl nitrobenzoate = 0.0367 mol × 181.04 g/mol
= 6.65 g
actual yield
Percentage yield = ×100 %
theoretical yield
3,5
= ×100 %
6.65
= 52.64 %
CHM457_MARCH-JULY 2020_ONLINE ASSESSMENT_COVID19
b) Explain why the isolated product yield is less than expected
Some of the product was spilled out during the collection. The preparation
of the nitronium ion. So this can cause the nitronium ion is unstable.
(3 marks)
v. Explain briefly why the experiment was conducted at a very low temperature of less
than 0°C.
The reaction mixture is poured over ice to precipitate the crude product. Ice is
used because the reaction of concentrated acids, especially concentrated
sulfuric acid, with water is very exothermic. This would lead to the hydrolysis
of the ester function during this step.
(2 marks)
vi. Explain why the final wash of the crystal product need to be tested with pH paper.
To ensure the final wash of the crystal product is neutral and no acid
impurities in it.
(1 mark)
v. Suggest a simple method to prove that the collected crystal is nitro methyl benzoate.
Determine the melting point and compare it with standard melting point of
nitro methyl benzoate.
(1 mark)
a. References (2 marks)
i. Di Somma, I.; Marotta, R.; Andreozzi, R.; Caprio, V. Kinetic and Safety
Characterization of the Nitration Process of Methyl Benzoate in Mixed Acid. Organic
Process and Development online.
ii. . Solomons, T. G. W.; Fryhle, C. B. Organic chemistry, 9th ed.; Wiley, John & Sons:
New York, NY, United States, 2007.
CHM457_MARCH-JULY 2020_ONLINE ASSESSMENT_COVID19
