Synthesis and recrystallization of acetanilide limiting reagent


In this experiment, the percentage yield of acetanilide can be acquired with the theoretical yield. We can get this when we compute for the limiting reagent in the reaction. The limiting reagent is the reactant that is completely used up in a reaction, and thus determines when the reaction stops. Here limiting reagent is acetanilide; hence yield shou+ld be calculated from its amount taken. Molecular formula of acetanilide = C 8 H 9 NO. Molecular formula of sulphanilamide = C 6 H 8 N 2 O 2 S. Molecular weight of acetanilide = 135 g/mole. Molecular weight of sulphanilamide = 172 g/mole. Theoretical yield: 135 g acetanilide forms 172 g ... acetanilide CH3 H O + acetic acid Both aniline and acetic anhydride are somewhat viscous liquids. So, simply mixing them together does not result in the efficient formation of acetanilide. Therefore, a solvent (in this case water) is used to dissolve and evenly disperse two reactants in it. R' N R" O R CH3 O acetyl group Note: R' N CH3 O R ... acetanilide CH3 H O + acetic acid Both aniline and acetic anhydride are somewhat viscous liquids. So, simply mixing them together does not result in the efficient formation of acetanilide. Therefore, a solvent (in this case water) is used to dissolve and evenly disperse two reactants in it. R' N R" O R CH3 O acetyl group Note: R' N CH3 O R ... This experiment aims to purify crude acetanilide water, the best recrystallizing solvent, which is determined by the solubility of the solid compound, to produce pure acetanilide and to calculate the percentage yield of the weight of the pure acetanilide. Also, it aims to prove the process of recrystallization in purifying compounds. Following the reaction and allowing to air dry, the mass of the acetanilide was determined to be 5.15 g. The limiting reactant was determined to be aniline and 7.7 g of product was theoretically possible. This allowed for a low 67% yield. The low yield is likely due to a combination of factors.