posted by Tammy on .
The isolation process of aspirin was stopped after the filtration step with alumina and one week later the methanol was evaporated and the experiment was completed. The melting point of the aspirin was found to be 110-115 Celsius. explain why the meltingpoint was low and why the melting range was so wide.
can you please help
also if the process would be completed on time what are the reasons that the % of recovery is less than 100% ?
The low and wide melting point could be low due to the sample being impure. Reasons include:
incomplete drying so that the sample still ocntains some methanol and/or water.
the sample may still contain some of the starting materials.
another possibility is did the sample smell of oil of wintergreen? If the aspiring is left standing in methanol some of the COOH group will be esterified to the methyl ester.
Any manipulation of a sample will result in small losses. You need to look at the steps you took to see where sample may have been 'lost'.