Cost Analysis and the Synthesis of Aspirin Chemistry Assignment using mo dified
ID: 589075 • Letter: C
Question
Cost Analysis and the Synthesis of Aspirin Chemistry Assignment using mo dified AACU Quantitative Literacy (QL) Value Rubric The synthesis of aspirin (acetylsalicylic acid) is performed by reacting acetic anhydride with salicylic acid, using a small amount of phosphoric acid, HPO. as a catalyst. Assurne the reaction's percent yield of the aspirin is 75%. The reaction is shown below: HsPO acetic anhydride salicylic acid aspirinacetic acid acetie anhydride salicytie acid Determine the cost of having a chemist produce 100 grams of aspirin in a small scale laboratory setting, such as the one you have been working in during your labs in this course. Information needed to do this is contained in the paragraphs below The project will involve taking the proper stoichiometric amounts of each chemical to react with each other that will produce 100 grams of aspirin, assuming the 75% yield stated above, plus 2 mL of the phosphoric acid catalyst. In addition to the costs of these starting materials, assume the reaction, the physical separation of the aspirin from the reaction mixture and the cleanup and disposal will take two hours of your chemist's time at $ 50 per hour. The costs of a piece of filter paper for collecting the aspirin product, some ice to force the aspirin out of solution and some water necessary to dilute the phosphoric acid and acetic acid and "deactivate" any unreacted acetic anhydride may be neglected. At the prices listed below, the purity of the materials is not "virtually perfect" but to keep the problem "manageable" we will assume they are, neglecting any impurities. Current Prices: Acetic Anhydride $84.00 per 1 kilogram bottle Salicylic Aci S 82.00 per 500 gram jar Phosphoric Acid 18.00 per 2 L bottle Construct a "Summary Report" that shows appropriately labeled calculations of the necessary amounts of the acetic anhydride and salicylic acid, the calculations of the costs of these materials and the costs of the phosphoric acid catalyst and the chemist's salary for the two hours of his or her work. The report should also include a Conclusions paragraph, summarizing the findings, acknowledging the assumptions and their effect on how the outcome might be different as a result of making those assumptions. Also include a result and comments related to the information below: A large chemic The cost of a 100 gram bottle of "house brand" al company does the same sort of process but on a much larger, more cost- effective scale. aspirin tablets at your local pharmacy is about $ 3.00 ng? How many times more expensive is it to produce the 100 grams of aspirin in the "small-scale" settiExplanation / Answer
Summary sheet
1. Calculations
Salicylic acid + acetic anhydride -->aspirin + acetic acid
in presence of H3PO4
amount of aspirin (theoretical yield) = 100 g x 100/75 = 133.33 g
moles aspirin = 133.33 g/180.157 g/mol = 0.74 mol
mass salicylic acid = 0.74 mol x 138.121 g/mol = 102.22 g
mass acetic anhydride = 0.74 mol x 102.09 g/mol = 75.55 g
Cost of salicylic acid = 102.22 g x 82/500 g = $16.76
Cost of acetic anhydride = 75.55 g x 84/1000 g= $6.35
Cost of H3PO4 = 2 ml x 18/2000 L = $0.018
Cost of cleaning = $50/hr
So total cost to produce 100 g aspirin = 16.76 + 6.35 + 0.018 + 50 = $73.13
House brand aspirin costs = $3
the prepared aspirin in lab is expensive by = 73.13/3 = 24.4 times
2. Conclusion : The prepared aspirin by this method in the lab is almost 25 times more expensive then the house brand aspirin available in the market. So the method is not feasible and economical.
3. Summary : In summary we can say that synthesis of aspirin on a small scale in the laboratory is tedius and very expensive with cost of total process extremely high. The product aspirin formed by this method is not economical to use and therefore cannot be continued.
4. Assumptions : The common assumptions taken in the experiment are that the purity of the formed product is close to the house brand aspirin and no further purification process is necessary for aspirin thus formed.
5. Results and comments : It is impossible to make aspirin at a lab scale in an affordable manner. The process thus has to be scaled up to reduce the product cost.