Question

water is added to the reaction at the end of the aspirin synthesis to [Select l addition of water creates Select l The

First choice: ( Hydeolyze excess acetic anhydride, form acetic anhydride from excess acetic acide , cool down the reaction , OR dilute the sulfuric acid)

Second choice:(  dilute the sulfuric acid, a room temperature reaction , acetic acide , OR acetic anhydride)

Please help thank you

Answer 1

Molar mass of salicylic acid = 138.12 g/mole molar mass of acetic anhydride = 102.09g/mole molar mass of aspirin = 180.15 g/mole mole of salicylic acid = 1.971 g/138.12 g/mole = 0.01427 mole moles of acetic anhydride = 1.08g/m times 4m/102.09 g/mol = 0.042 mole salicylic acid is limiting request therefore moles of aspirin forms = 0.01427 mole mass of aspirin = (theoretically) = 0.01427 times 180.15 = 2.5707 g % yield = 23.373-21.036/2.5707 times 100 = 90.90%