Question

Exercise 7: The % Yield of Aspirin Name Date Read Exercise 7 in your lab manual. Complete the Pre-lab Assignment. In this substitute lab exercise, you will watch a short video on preparing aspirin. The video is posted on the course Moodle page, and it provides the masses of the reactants and the product; you should be able to calculate the theoretical yield and the % yield from the data given by the video. Submit the completed assignment by March 25, 11:55 pm. 1. Write the chemical equation for the formation of aspirin from salicylic acid and acetic anhydride. Show the condensed structural formulas of all reactants and products. (Sulfuric acid is a catalyst for this reaction; you do not need to show the structure of sulfunc acid.) ICOH G to-&-CH3 + CH- & olf + Cita-C-OH Anhydride de Salicylic Asprin Acid 2. Calculate the molar masses of the following compounds. Record the mass of salicylic acid used and the mass of aspirin obtained in the video. Use the molecular masses to calculate the moles of each: Molar Mass Mass Amount 38 g/mol 2.027 B 147 mol 102 g/mol acetic anhydride 4.00 mL 0.0423 mol filter paper No data 1.354 8 No data Aspirin +filter paper No data 2.711 8 No data 150 /mol 2.357 8 013) mol salicylic acid filo poper 3549 Aspirin Show the calculation for the number of moles of salicylic acid and of aspirin here: salicylc acid 2.027 - 00147 mol 138 Aspirin 2.357 - 0131 mol 180 Based on the data above and the balanced equation, which reactant is the limiting reagent? Salicyclic acid is the

Answer 1

e. te anhside of talren acetic antglide he theortical yield - . Salicyclic acid is taken Seed Cat & 0.0423 mole 0.0147 mole 180 " - ca , c o I ooty 7x son OH & Cillc - BH (As pein) (sality dicoed.) (onlydice) nou the beeation's (1:1) molat latio. and since here Salicyclic acid is listing lectant So alto leaction colunmole of Salicylic coad - 0.0147 mole of Apie 0.0147 moles & Ymole the retical fied = ☺ 2.646 g (glans) inades (0.0147) onda) a 0.0131 xloo Actual siek & 100 = 0.01417 89.115.%. the Ritical Yield (interns y modes).

Questions

1) the impurities which are most likely present in aspirin is salicylic acid and anhydride.

2) if the %yield is less than 100 means more sample was recovered from a reaction than predicted. And if %yield is over than 100 which means the product which we obtain has more impurities that cause it's mass to be greater than it's actual mass.

3)

4.

Ethyl-acetate estel 4) Equation of CH3 - CH₂ – OH at CH₃ - Cnoth H (ethanoic aud) CH₂ - Co- CH₂ - CH₂ (ethyl ethanoate) + H₂O (ethand)