CHEM 162 LAB #6: SYNTHESIS OF ASPIRIN Goals of this lab: • Synthesize aspirin and evaluate the product for purity and yield • Perform stoichiometry calculations to determine expected yield vs. percent yield • Apply Beer’s law to determine the amount of impurity in the crude product • Compare melting points of the crude product and pure aspirin to evaluate determine relative purity of the product Your lab report will be graded on the following criteria using a poor/good/excellent rating system: • Calculations are accurate and complete based on data gathered; proper significant figures and units are used • Data collected is reasonable; measurements are careful and accurate • Conclusions are reasonable and logical • Lab report is completed neatly with organized responses and legible handwriting By signing below, you certify that you have not falsified data, that you have not plagiarized any part of this lab report, and that all calculations and responses other than the reporting of raw data are your own independent work. Failure to sign this declaration will result in 5 points being deducted from your lab score. Signature: This lab is worth 60 points: 10 points for notebook pages, 50 points for the lab report (Do NOT include your notebook pages when you scan your report for upload into Gradescope.) NAME Necia Riojas Quiz Section AJ Student ID 1925927 Necia Riojas # Necia Riojas AJ 1925927 NAME Quiz Section Student ID Page 2 of 5 This study source was downloaded by 100000840471888 from CourseHero.com on 12-08-2022 10:57:56 GMT -06:00 https://www.coursehero.com/file/66977636/Chem162-Report-6pdf/ NEATLY show your work. Use a reasonable number of significant figures, include units with your data, and keep your answers concise. Part I. Synthesis of Aspirin Table 1 Value Units Mass of salicylic acid 0.209 g Volume of acetic anhydride 0.48 ml Volume of phosphoric acid 2 drops Temperature of reaction 65.8 °C Mass of filter paper + watch glass 31.560 g Mass of filter paper+ watch glass + crude product 31.738 g Part I Calculations and Results 1. Calculate the actual yield of crude aspirin product. Neatly show your work. Calculation summary: How much crude aspirin did you produce? 2. The procedure requires that acetic anhydride reactant be present in excess. Demonstrate that this is the case with your reaction by providing a stoichiometry calculation using your data and the density of acetic anhydride (1.082 g/mL). For full credit, be sure to show all of the required work and explicitly compare the amounts of reagents used. 31.738 g – 31.560 g = actual yield = 0.178 g 0.209 g salicylic acid *(1mol salicylic acid/ 138 g salicylic acid) *(1 mol aspirin/ 1mol salicylic acid) *(180 g aspirin/ 1 mol aspirin) = 0.273 g aspirin (this is also the Theoretical yield) 0.48 ml acetic anhydride *(1.082 g/ 1 ml acetic anhydride) *(1 mol acetic anhydride/ 102 g acetic anhydride) *(1 mol aspirin/ 1 mol acetic anhydride) *(180 g aspirin/ 1 mol aspirin) = 0.917 g aspirin