If 4.2g of aspirin was initially obtained from the reaction above and 1.3 g of t
ID: 1071107 • Letter: I
Question
If 4.2g of aspirin was initially obtained from the reaction above and 1.3 g of the aspirin was reared after recrystallization (i) What was the percentage recovery? (ii) what was the theoretical yield? (iii) What was the percentage yield? (iv) what would be the theoretical yield of aspirin if 3.8 m mol of salicylic acid is used? From "Thin Layer Chromatograph, TLC" Experiment a. Determine your unknown component(s) b. Calculate the unknown Rf values When rinsing recrystallized crystals on a Buchner funnel during vacuum solvent why should the solvent be while collecting the crystals? Analyze the attached IR. Use the molecular formula to determine the degrees of unsaturate in the molecule Draw a structure of the compound that matches the IR and assign the peaks of the spectrum.Explanation / Answer
10. For the aspirin formation
(i) percent recovery = 1.3 x 100/4.2 =
(iv) Theoretical yield of aspirin = 3.8 mmol x 180.157 g/mol/1000 = 0.686 g
11. TLC
a. unknown = excedrin
b. Rf = 4.5/8.2 = 0.55
12. the solvents must be cold while washing or the compound would dissolve in the added solvent and pass out into the filtrate.