The Identity of the unknown, in this case unknown A, was determined to be acetyl salicylic acid. This was determined by comparing the melting points of the purified unknown crystals to the crude unknown. The known melting point range for acetyl salicylic acid is 135°C -136°C. The Unknown’s melting point was slightly off at 128.6°C - 132°C. This can be due to impurities of the crystals during the purification process. There were a few steps in the experiment that may have contributed to impurities in the unknown crystals. In the beginning of the experiment, the column with alumina was used to filter the methanol/unknown mixture into a vial. It was important to add the mixture after methanol was added to the column and was still above the top