The objective of this experiment was to purify the aspirin compound through recrystallisation and to determine the percentage yield as well as the melting point of the obtained aspirin.
For the synthesis and recrystallisation of the aspirin compound, salicylic acid reacted with acetic anhydride in a conical flask. Drops of concentrated sulphuric acid were added into the conical flask and then heated using a hot water bath. Right after the mixture finished heating, drops of deionised water were added. Then, cold water was added into conical flask before a crude aspirin sample was collected using suction filtration. The crude sample was then dissolved in ethanol, followed by hot deionised water, and warmed until all the solids had dissolved. After, the mixture was cooled. Suction filtration was then used again to collect the recrystallised aspirin compound. Lastly, the aspirin was placed in the oven, followed by the desiccator and then weighed.
The appearance of the dried, recrystallised aspirin was flaky, shiny and silvery. The melting range was observed to be from 131.3°C to 133.9°C, which shows that the aspirin compound was impure. The percentage yield was also calculated to be 44.1%, which is considered to be a low yield.
Aspirin (acetylsalicylic acid) has been sold commercially for many years, and used as a way to reduce fever, redness, pain, swelling, inflammation and also to relieve headaches. Aspirin manages to relieve the body of discomfort by blocking natural substance in the body, which results in the pain and swelling being reduced.
Before the first discovery of the modern day aspirin, many people had already been using one of the key ingredients of aspirin (salicylic acid) to relieve pain. However, consuming salicylic acid alone had incidents of causing nausea, vomiting, and some even ended up in a coma. Thankfully, the modern day aspirin pills that are made of acetylsalicylic acid were first discovered was when Felix Hoffmann’s rheumatic father encouraged his to produce a medicine to help his rheumatism. This resulted in Felix Hoffmann, a chemist in the pharmaceutical laboratory of the Friedrich Bayer ; Co, consulting the chemical literature and coming across the synthesis of acetylsalicylic acid. He then prepared the first sample of pure acetylsalicylic acid on 10 August 1897. The first sample of aspirin was then sent into the market in 1899 as a safe way of consuming salicylic acid without experiencing the unpleasant effects that came along with just consuming salicylic acid alone.