Now do your own synthesis and determine the percentage yield from your own results. How can iron(III)chloride be used to check the purity of aspirin formed? FeCl 3 turns from a yellow to a purple colour in the presence of salicylic acid, as shown on the right. Discuss a possible error that would cause this yield.ħ. Is this percentage yield possible? Explain. Calculate the percent (%) yield from the actual product mass. Synthesis Reference(s): The Journal of Organic Chemistry, 27, p. Calculate the theoretical yield of aspirinĦ. On the left is the chemical equation for the formation of aspirin.ĥ. Learning Outcome: Student will be able to: 1) Recall the units for molarity, concentration, ppt, ppm & ppb 2) Convert molarity to concentration, ppt, ppm, ppb & vice versa 3) Understand the concepts of dilution and standardization 4) Differentiate the properties of primary and secondary standards and standard solution 5) Prepare standard solution by direct method and by standardization 6. Calculate the mass of acetic anhydride from its volume (10 mL) and density (1.08 g/mL)Ĥ. Determine the mol of salicylic acid used if the molar mass of aspirin is 180.16 g/mol and the molar mass of salicylic acid is 138.12 g/mol.Ģ.
Step 8 Weigh the precipitate and filter paper.ġ. Allow the precipitate to dry overnight before weighing. Step 7 Use a small spatula to remove the filter paper and aspirin. Rinse the precipitate with distilled water. Tee water in the flask should start to look cloudy as the precipitation takes place.Īfter a while the crystals should grow in size and the water becomes clear, as shown on the right.Ĥ) Set up the Vacuum Filtration apparatus.Ħ) Filter the acetylsalicylic acid from the funnel. Question An early proposal in this research was that the tobacco plant could utilize two molecules of salicylic acid (molar mass 138.12 g/mol) in a. Crystallisation can be increased by scratching the internal surface of the flask with a glass rod while swirling the contents. Small crystals of the acetylsalicylic acid (aspirin) should begin to appear as the mixture cools.
Then add 100 mL of near freezing, cold water kept in an ice bath. Swirl and heat on a hot plate at at 50 oC until the salicylic acid has dissolved.ģ) Take the flask off the hot plate and allow to cool. Record the mass of salicylic acid to the nearest 0.01 gram.Ģ) Take the flask containing the salicylic acid to the a fume cupboard and add 10 mL of acetic anhydride and 1 mL of concentrated sulfuric acid. Organic chemistry-making of acetylsalicylic acid (aspirin) Synthesis of Aspirin.ġ) Tare a 250 mL conical flask and into it place approximately 3.00 grams of salicylic acid.
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