Synthesis of aspirin lab report answers Rating:
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Aspirin, also known as acetylsalicylic acid, is a commonly used pain reliever and anti-inflammatory medication. It is synthesized through a chemical reaction known as esterification, which involves the reaction of salicylic acid with acetic anhydride in the presence of an acid catalyst.
In a lab setting, the synthesis of aspirin can be demonstrated by carrying out the following steps:
Prepare a solution of salicylic acid in a small amount of water.
Add a small amount of concentrated sulfuric acid to the solution as a catalyst.
Slowly add acetic anhydride to the mixture, while stirring constantly.
Continue stirring the mixture until it becomes thick and pasty.
Allow the mixture to cool, and then filter it to separate the solid aspirin from the liquid.
Wash the solid aspirin with a small amount of cold water to remove any excess reagents.
Dry the aspirin thoroughly, and then weigh it to determine the yield of the synthesis.
In order to determine the purity of the synthesized aspirin, it can be analyzed using thin-layer chromatography (TLC). This technique involves separating the compounds in a sample based on their relative ability to move through a stationary phase, such as a layer of silica gel or cellulose. The sample is applied to the TLC plate, and then the plate is placed in a solvent, which causes the compounds to move up the plate at different rates based on their affinity for the solvent and the stationary phase.
After the TLC plate has been developed, it can be sprayed with a reagent that will cause the aspirin to change color, allowing it to be visualized and identified. The purity of the synthesized aspirin can then be determined by comparing the intensity of the aspirin spot on the TLC plate to the intensity of a reference spot, which is a known pure sample of aspirin.
In conclusion, the synthesis of aspirin involves the esterification of salicylic acid with acetic anhydride in the presence of an acid catalyst. The purity of the synthesized aspirin can be determined using thin-layer chromatography, which separates the compounds in a sample based on their relative ability to move through a stationary phase.
Aspirin synthesis Lab report
Thus, there was error percent in gaining the product while using the technique of crystallization and vacuuming. Some potential errors could have been letting the synthesis reaction run too long or letting the flask cool for too long during the recrystallization. There were no errors in this experiment. The 0 % difference between the theoretical and actual aspirin recovered, can be attributed to incomplete reactions as a result of insufficient heating time or amount of catalyst added to the reactant mixture, earlier in the synthesis. Ice DI water was used in transferring remainder of the crystals in vial to Hirsch funnel. Determine the optimal wavelength for creating the standard curve and set up the mode of data collection. Tube 2 shows faint yellowish color due to the presence of aspirin.
The first pile was mixed together, the second pile was added to acetanilide, and the third pole was added to phenacetin. Your observations of the experiment as it progresses is important, new information. Causes mild skin irritation. Aspirin: Health benefits, uses, and risks. Salicylic acid is toxic and causes mild skin irritation and severe eye damage in case of contact. You can use this information to calculate the purity of your aspirin sample.
The percent yield of aspirin was calculated to be 88%. Set up a 150 mL beaker with water to warm up on a hot plate medium heat 2. I believe there may have been errors in my technique that could have led to different values. Calculate the percent yield of your synthesis. Another cause of error could be with the aqueous salt; not all the aspirin salt reacted with the HCL which would be filtered off, In addition, some of the aspirin could have been left with the unknown and later evaporated in the DCM.
When most of the liquid has been drawn through the funnel, turn off the suction and wash the crystals with 5 mL of cold, distilled water. Visualization of the sample - our result will be viewed under UV light 4. Also, the melting point range will seem broader than it really is. Signals that corresponds with the aromatic ring of the salicylic acid will also be present, these signals are quite similar to those of the aromatic ring in acetylsalicylic acid, two doublets and two triplets within the range of 7-8 ppm. Insert the Buchner funnel into the flask; make sure the funnel is properly resting on the Buchner ring.
Have access to eyewash. Aspirin has many uses in medicine, it is very versatile. Once the crystals dissolved, the flask was covered and left to cool to room temperature before it was placed in an ice bath for 10 minutes to fully crystallize. Salicylic acid is extremely bitter tasting, and frequent use can cause severe stomach irritation. There mass is measured and recorded then the yield is calculated. It is broken down into two smaller reaction, saponification and esterification. Thus, pure aspirin was synthesized.
The OH on the aromatic ring is deprotonated and the acyl groups reacts with the oxygen to create the ester Clark, 2019. Addition of denaturant makes the product poisonous. Discussion Question 1: The signals for the aromatic protons seem to fall within the range of 7. Discard the capillary tube and sample as directed by your instructor. When adding a few drops of concentrated sulfuric acid, which acted as a catalyst, effervescence transpired and some of the salicylic acid dissolved. This result proves that the unknown tube contain pure aspirin as the color shows faint yellowish instead of showing dark purple.
Mix the solution thoroughly. Swirl the mixture to dissolve the solid. The iron chloride test proves the presence of pure aspirin as it shows more faint yellowish color instead of dark purple. Ashley Islam TA Jeremy Liew Chem L255 December 1st, 2020 Aspirin Synthesis Abstract: The main objective of the experiment is to synthesize acetylsalicylic acid aspirin through esterification of salicylic acid and acetic anhydride using phosphoric acid as a catalyst. The signal at around 11-12 ppm would also be expected for acetylsalicylic acid. Obtain acetic anhydride that you need for your reaction in your 10 mL graduated cylinder. The two values marked on your graph describe the estimated melting temperature range of your substance.
Theoretical yield is 2. Esterification reaction is used in the manufacture of paints, varnishes, lacquers, medicines, dyes, soaps and synthetic rubber. A percent yield of 23% was calculated from our theoretical and actual yield. This same test can be used when seeing how pure a sample of salicylic acid. The created of the desired product, acetyl salicylic acid, was confirmed using NMR analysis.
Collected crystals by vacuum filtration again. Another error that would have significantly affected the results is not letting the flask to sit in the temperature bath for long enough as it would decrease the amount of aspirin that is synthesized. Note: If the absorbance value does not fall within the range of the salicylic acid standard solutions in your data table, you can repeat Step 22e using a more dilute or more concentrated solution. If necessary, use a sparingly small amount of distilled water to rinse down any bits of solid that may be on the inner walls of the flask. When these compounds are mixed with the unknown they are reduced to approximately 92 C and 104 C respectively. Introduction Although seemingly complicated the aspirin synthesis reaction is actually quite simple.
Sulphuric acid is added to the mixture and is swirled. They are to explain activity WM5. Discussion Question 2: The combined peaks of both salicylic and acetylsalicylic acid would be observed in the H NMR spectrum. Synthesis of Aspirin Acetylsalicylic Acid Abstract: This experiment is about the synthesis of aspirin under laboratory conditions. The polarity of aspirin is the reason for its melting point has such a wide range. Once solid dissolved, weigh the watch glass and filter paper, use the filter paper to carry out suction filtration, place crystals on watch glass, weigh the dried crystal and calculate the weight of the aspirin.
