Experiment 4a –
The aim of the experiment is to determine the amount of aspirin produced. 1.5 g of salicylic
acid is weighed and kept in a beaker, then 3ml of acetic anhydride followed by 10 drops of
concentrated phosphoric acid is added to the solution. The solution was stirred for an
additional 5 minutes. After heating the solution 25ml of water was added to it and was kept for
a while for it to cool down. After 5 minutes this solution was kept in a larger beaker
containing ice and water for another 10 minutes. Once the solid was crystallized, it was filtered
using a buchner funnel at the vacuum filtration setup followed by the addition of DI water for
approximately 20 …show more content…
However, the aspirin
was in a powdered form so, it was loaded into a thin capillary tube for determining the melting
point. The capillary tube is put in one of the slots in the melting point apparatus. A 75 volt of
energy was provided for the aspirin to melt. The energy was then slowly lowered to 65 volts
and thus the melting point of aspirin was obtained which came out to be 119 to 123 in Celsius.
The melting point of aspirin is 136 in Celsius as compared to the result found of 119 to 123 in
Celsius. It is different because there might be some impurities present in the aspirin formed so
it has disturbed the crystal lattice of aspirin.
Part 2 – Spectroscopic analysis.
0.239 g of aspirin is weighed in a beaker where 5 ml of 1.0M sodium hydroxide is added which
converts aspirin to salicylic acid. A transfer pipette is used to transfer 20ml of the solution to
100ml volumetric flask which is then rinsed with DI water. Furthermore, the concentration of
the synthesis product is calculated using the formula M1V1=M2V2 where M2 is the unknown