The objectives of this experiment are to carry out the process of synthesising aspirin and reinforce both the skills of recrystallisation and melting point determination. In this experiment, we are supposed to measure the amount of aspirin collected to calculate the percentage yield of aspirin. Apart from that, we are also required to find the melting point of aspirin.
Introduction:
1.1: aspirin
Aspirin, also known as acetylsalicylic acid, is an aromatic compound containing both a carboxylic acid functional group and an ester functional group. Aspirin, being a monoprotic weak acid, is only slightly soluble in water and it can be prepared by reacting salicylic acid and acetic anhydride in the presence of an acid catalyst.
1.2: History of aspirin
Aspirin was first produced about 110 years ago but the natural form, salicylic acid, found in plants (i.e. the willow and myrtle) has been used for thousands of years. However, as time goes by, more scientist discovered better and more modern ways to improve salicylic acid.
1.3: Uses of aspirin
Aspirin is used to treat pain, and reduce fever or inflammation. It is sometimes used …show more content…
If the substance melts over a very narrow range, it is assumed that the substance is relatively pure. Conversely, a compound that melts over a wide temperature range is assumed to be relatively impure. The melting point range of aspirin obtained from this experiment is 134.8-137.1 ̊ C and it has a difference of 2.3 ̊ C. This shows that the crystals obtained are not very pure. However, the literature melting point range of aspirin is 136 .0 ̊ C. The temperature range obtained from the experiment is quite close to the literature melting point range with a difference of approximately 1.2 ̊ C , the difference is not very large. Hence, the crystals obtained from the experiment is aspirin but contain