Question

How to calculate theoretical yield & actual yield for this problem.

A student used 3 mL propanal and an equimolar amount of acetophenone as starting materials for the aldol condensation experiment. Sodium hydroxide was used for the base and ethanol was used for the solvent. After refluxing and purification, He/She obtained 3.9 g of the product.

Answer 1

3 ml rightarrow propanal density of propanal = 0.810 g/ml density = mass/volume mass of propanal = density times vol^n = 0.81 times 3 moles of propanal = mass of propanal/molar mass = 2.43 g/58.08 g/mol = 0.0418 mol Ac. to reaction propanal + acetophenol rightarrow ^NaOH product we take equimolar 1 mole of propanal product rightarrow 1 mole of product 0.0418 mole of propanal produce = 0.0418 mol of product mass of product = moles times molar mass of product (C_16H_14O) (222 g/mol) = 0.0418 times 222 Theoretical yield = 9.2796 g actual yield = 3.9 g % yield = actual yield/Theoretical yield times 100 = 3.9/9.2796 times 100 % yield = 42.027%