Question

A student reacts 100g of salicylic acid with 17 mL of acetic anhydride producing 12.9g of acetyl salicylic acid. What is the percent yield of the reaction?

Answer 1

salicylic acid + Acetic anhydride --------> acetyl salicylic acid

here acetic anhydride is reagent and salicylic acid is reactant

so first calculate the no of moles of reactant

next calculate the no of moles of product

now % of yield = (moles of product / moles of reactant)    x 100

no of moles of salicylic acid = weight of salicylic acid / molar mass of salicylic acid    

= 100g/138.12g/mol = 0.724 moles

now no of moles of acetyl salicylic acid = weight of acetyl salicylic acid / molr mass of acetyl salicylic acid

= 12.9g / 180.16g = 0.0716 moles

now % of yield = (0.0716 / 0.724) x 100    = 9.8895   = 10%