Question

Calculate the number of moles of acetic anhydride present in the reaction mixture. c. w d. Based on the number of moles of each reactant and the stoichiometry of the reaction, determine the limiting reactant in the preparation. Calculate the theoretical yield of the preparation, based on the number of moles of limiting reactant present. e. Calculate the percent yield of the preparation. f. Preparation of Aspirin Page 86

Answer 1

Reaction involved in synth creations that c on tuote OM Salicylic acid . Acele anhydride to Aspirin Acitie acid (a) Moles of salicylic acid present in reaction mixture = got of salicylic acid taken Molecular mass of salicylic acid = 2.775 gm = 0.02009 moles - 138.121 gmail . (b) Mais of acetic anhydrude used: Density of acetic anhydride - 1.08 g/ml I density - Mars Volume Mais of acete anhydrude taken a density & Volume take = 1.08 x 4 = 4.32 gm o Moles of acetic anhydride in reaction mixture = Maus of acetic anhydride (calculate in (67) Molecular Mais of acetic anhydride = 4.32 gm 0.0423 moles 102.09 gmots for reaction

(d) According to reaction stoichiometry, . 1 mol of salicylic acid react with a moles of acetic anhydride to form 1 mol of aspirin : In our reaction mixture, 0.02009 moles of salicylic aid and -0.0423 moles of acetu anhydride present Moles of salicylic acid es dees, so it decide the amount of product formed, thence it is limiting reagent,

(e) Theoretical Yield: It is amount of product should be formed according - to balanced equation, by limiting reagent (salicylic acid) Acc. to eqh : 1 mol of salicylic acid gives 1 mol of aspirin We have 0 0 2009 mol of salicylic acid gives 0.02009 moles of aspiring Theoretical yield of aspirin a 0.02009 moles (limi regent)

. (f) Porcentage Yeedd = - Actual Yeld of Aspirin ... rapeun x Theoretical Yield 100 a Moles of aspirin formed after reactions x 100 Theoretical Yield e too gut of aspirin formed Molecular Mais y - Theoretical Yield = 2.986 gm / 180.158 gmail x 400 0.02009 moles - 0.01657. x too 0.02009 2 82.478%