Recrystallization Lab

I performed a number of steps during this recrystallization lab in order to achieve the desired results, which included heating the solvent, completing a hot filtration, completing a vacuum filtration of a chilled solution, as well as drying and calculating the weight and melting point of the final version of the sample. I began the lab with 1.5 grams of the impure acetanilide solute and ended the lab with 0.05 grams of pure acetanilide crystals. The percentage of pure acetanilide I recovered during this lab was 3.33%, which is lower than I expected. However, the low percentage shows that the impurities within the original impure acetanilide solute were removed. A number of factors could have caused the low yield of pure crystals. The melting
One example would be that too much or too little water was added to the solute during the original dissolving of the impure acetanilide solute. Too little water would cause the solute to not fully dissolve, while excess solvent would result in more heating of the solution. Another example of error that could have occurred is having a malfunction with the apparatus setup and losing the sample, which would result in starting over on the lab. It was imperative that the water was turned off after disconnecting the tubing to the water aspirator so that the filtrated solution was not contaminated. An additional instance of error could be that the solution was not allowed to cool slowly after the initial hot vacuum filtration. This error would result in the undesirable formation of small, contaminated crystals. One final instance of error would be the miscalculation of the weight of the original, impure acetanilide and the final, pure crystals. Many students seem to be unaware of the correct way to weigh a solid sample on a scale with a weigh boat, which in turn could affect their percentage of pure acetanilide that was