A student decided to extract aspirin from a tablet. After the alumina filtration step, he stopped the experiment for a week. then he evaporated the methanol and completed the procedure. the melting point of his recovered material was 120-145 degrees Celsius. what does this wide range tell us? what might have happened?

(the normal melting point of aspirin is 135-136 dgrees celsius)

The evaporation procedure must be completed in 10-15 minutes right after isolating aspirin in the filtration step with alumina or the aspirin decomposes which will create more surface area on the molecule resulting a lower melting point and wider temperature range.

The wide range of melting points observed (120-145 degrees Celsius) compared to the normal melting point of aspirin (135-136 degrees Celsius) suggests that the recovered material may not be pure aspirin. The melting point of a substance is a characteristic property and usually remains fairly constant unless impurities are present.

One possible explanation for the wide melting point range is the presence of impurities in the recovered material. Impurities can lower the melting point of a substance or cause the range to broaden. In this case, the student might have introduced impurities during the week-long break, or they may have been present even before the break.

During the week-long break, the aspirin solution in methanol could have undergone various chemical reactions or reactions with atmospheric moisture, leading to the formation of impurities. Additionally, methanol, being a volatile solvent, evaporates easily, which might have caused the concentration of impurities to increase as the solvent evaporated.

It is also worth noting that the prolonged time between the alumina filtration and the completion of the procedure could have allowed for degradation or decomposition of the aspirin, leading to the formation of additional compounds.

To obtain a more accurate melting point for aspirin, it is important to ensure that the compound is pure. This can be achieved by using fresh solvents, utilizing proper filtration techniques, and minimizing the time between filtration and subsequent steps in the procedure.