Date Report Written: 08/02/2009
Synthesis of Acetyl salicylic acid (Aspirin)
The following report contains information on how to produce aspirin. The experiment has been carried out on a small laboratory scale. The experiment starts by combining such chemicals such as salicylic acid and acetic anhydride. The synthesis of aspirin is classified as an esterification reaction. This is a substitution reaction where the alcohol group from salicylic acid reacts with ascetic anhydride to form an ester, (acetylsalicylic acid) which is commonly known as Aspirin. The report progresses further giving details to the procedure carried out and the experimental technique that has been developed to show how aspirin is produced. The report tests the melting point of the aspirin produced compared to textbook values as tests the amount of yield produced. The report also mentions how there are factors in the production of aspirin and how they affect the yield and purity. These can be found under the hypothesis subheading. As the report progresses the answers to the hypothesis become clear. The report then approaches to the hazards and risk analysis of the chemicals involved in the experiment and how precautions are taken to reduce these risks. The original data and obtained data are revealed, and then they are discussed with thorough interpretations along with conclusions made, as well as recommendations. Any information that is included in the report will be referenced at the end.
The following hypothesis will be tested:
➢ What is the actual yield produced in the experiment compared to the theoretical yield? ➢ Why are the reasons for this yield?
➢ What is the melting point of aspirin?
➢ What is the solubility of Aspirin in water?
➢ How is this affected by temperature changes?
➢ What are the major differences between your experimental process and the process most widely used in industry?
An experiment will take place producing aspirin (Acetylsalicylic acid) from Salicylic acid and acetic anhydride. Once the aspirin has been produced in the laboratory, its yield will be measured. From analysing the original data values it is possible to calculate the theoretical yield using moles and masses. Comparing the theoretical yield with the actual yield produced, the quality of the experiment carried out will become evident. Temperature will be one of the hardest aspects to control; the quality of the experiment heavily lies on this. Therefore the difference in yield from the actual yield produced compared to the theoretical yield will give a direct indication on how temperature changes affects the aspirin produced. As the yield is produced its melting point will be found, and it will be compared to values of aspirin that have been stated in chemical textbooks. Then it will be discussed as to why the yield produced are the same or different and also why the melting point are the same or different. Using these ideas it will be deduced as how the temperature of water affects the solubility of the Aspirin. Then a comparison will be made between the experiments carried out in the laboratory and how the production of aspirin is carried out in industry. The information on how aspirin is carried out in industry will be established using various text books and internet sources that will be referenced at a later date.
Procedure and Experimental Technique:
Method of Production of Aspirin:
➢ Before starting the experiment, read the COSHH analysis sheets for each of the chemicals that are going to be used in the experiments. This way an idea of the safety conditions and the handling of chemicals can be considered. ➢ Measure out 50g of salicylic acid with care.
➢ Measure out 80ml of acetic anhydride.
➢ Using a round-bottomed Quick-fit flask mix the measured Salicylic acid and the...