Synthesis of Aspirin Report Sheet PDF

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Laboratory 8: Synthesis of Aspirin Synthesis of Aspirin Report Sheet Synthesis of Aspirin DATA: Mass of salicylic acid

_____6 g_________________

Theoretical yield of Aspirin

____7.826 g______________ (calculated in #3 below)

Mass of crude aspirin

______7.6 g________________

Mass of pure aspirin

________0.91 g______________

CALCULATIONS: (Show All Work!) 1. a. What is the formula for acetic anhydride?

C 4H 6O 3 b. What is the molar mass of acetic anhydride?

102.09 g/mol c. If the density of acetic anhydride is 1.080 g/mL, how many grams of acetic anhydride did you use in the experiment? (show your work)

12.00 ml of acetic anhydride used * 1.080 g/ml, = 12.96 g 2. a. Calculate the number of moles of acetic anhydride and the moles of salicylic acid used in the experiment.

12.96 g / 102.09 g/mol = 0.1269 moles b. Which is smaller- #moles Salicylic Acid or #moles Acetic anhydride? (This defines the “limiting reagent”)

Salicylic acid moles = 6 g/ 138.121 g/mol = 0.04344 moles, salicylic acid is the limiting reagent 3. What is your theoretical yield of aspirin?

Aspirin molar mass= 180.158 g/mol, so 0.04344 moles * 180.158 g/mol = 7.826 g 4. What is your percent yield of aspirin? (calculate based on the mass of your recrystallized/pure aspirin)

Amount of Crude aspirin used for recrystallization = 2 g Amount of Pure aspirin after recrystallization = 0.91 g 0.91 g / 2 g * 100 = 45.5 % yield 5. Comment on the results of your ferric chloride test. Was there a benefit to recrystallizing your crude aspirin based on this test?

The test showed that the crude aspirin contained some salicylic acid, as shown by the purple color change. The pure aspirin had a rose gold color, and the recrystallized aspirin had a brown-pinkish color. There was a benefit of recrystallization as the crude sample contained some salicylate. QUESTIONS: 1. Why was cold water, not warm water, used to wash the aspirin you prepared?

Warm water will dissolve the crystals, and so reduces the percentage yield. 2. Comment on part II of the experiment, Formation of Methyl Salicylate.

The Methyl Salicylate ester had a mint-like smell. 3. Consider the manufacture of aspirin. Low-dose aspirin tablets are formulated to contain 81 mg of aspirin. How many kilograms of aspirin should the manufacturer produce in order to make 3000 low-dose aspirin tablets? (show your work)

1 tablet contains 81 mg of aspirin * 3000 tablets = 243,000 mg of aspirin is needed * 10 -6 kg = 0.243 kg of aspirin should be produced to make 3000 81 mg aspirin tablets. 4. A 5.018-gram sample of a certain hydrate of magnesium sulfate, MgSO4•xH2O, is heated until all the water is driven off. The resulting anhydrous compound weighs 2.449 grams. What is the formula of the hydrate? (show your work)

MgSO4 molar mass = 120.37 g/mol 5.018 g (hydrate mass) – 2.449 g (anhydrous mass) = mass of hydration = 2.569 g / 18.02 g/mol = 0.1426 moles 2.449 g / 120.37 g/mol = 0.02035 moles 0.1426 moles / 0.02035 moles = 7 so MgSO4•7H2O 5. Use the web to find one medical use of aspirin other than pain relief. Aspirin also has some hazards associated with its medical use. Find two of these also. Provide a proper ACS citation of your source of information. 5-point Bonus for using and citing a primary literature source rather than the web or other secondary source such as a book or magazine. Benefit of aspirin

A 40 mg daily dose of aspirin reduces the risk of Alzheimer’s disease dementia in Type-2 Diabetes Mellites patients. Source: Chang, C; Horng, J; Hsu, C; Chen, J.-M. Mean Daily Dosage of Aspirin and the Risk of Incident Alzheimer’s Dementia in Type 2 Diabetes Mellitus: A nationwide retrospective cohort study in Taiwan. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5102734/ (accessed Mar 9, 2020)

Hazards of aspirin Although low-dose aspirin use have shown to reduce the risk of cardiovascular disease, chronic consumption in asymptomatic-cardiovascular-patients increased the risk of intracranial hemorrhaging. Source: Huang, W.-Y.; Saver, J. L.; Wu, Y.-L.; Lin, C.-J.; Lee, M.; Ovbiagele, B. Frequency of Intracranial Hemorrhage With Low-Dose Aspirin in Individuals Without Symptomatic Cardiovascular Disease: A Systematic Review and Meta-analysis. https://www.ncbi.nlm.nih.gov/pubmed/31081871 (accessed Mar 9, 2020)....