Some test tubes contained polymerized product that was not added to the flask. When you are ready to proceed, crush these tablets using a mortar and pestle until you have a coarse powder. Reweigh your sample and record the new mass sample. As such, it is used to treat , , , , , and. Tap the crystal product down to the bottom of the capillary tube. These resonance forms will help you understand why a partial positive charge appears on the carbon atom in acetic anhydride and how this results in a new bond forming at that carbon.
Transfer the crystals to a beaker. Heat a large quantity of solvent to boiling point, and slowly at the hot solvent to the sample in the Erlenmeyer flask 3. Add 3-4mL of acetone or 4-5mL of isopropanol per expected gram of acetylsalicylic acid to an appropriate container, and add in your powdered aspirin. Synthesis of Aspirin acetylsalicylic acid Salicylic acid will rapidly react with acetic anhydride in the presence of an acid to produce aspirin acetylsalicylic acid and acetic acid ethanoic acid. However compared to the theoretical yield it is evident that there was a great loss of aspirin that should have been formed. It is an acetyl derivative of salicylic acid.
Lower absorbance values would indicate that a greater concentration of phenol was present and the absorbance value could be used to directly determine the concentration 1 Cappelli, G. Make sure to get as much of the product into the Buchner funnel as possible. You will also probably smell some vinegar with this synthesis using acetic anhydride especially after destroying the acetic anhydride with water. Added both to 50 mL Erlenmeyer flask + stir bar. The elapsed time was noted and recorded.
Be sure the water is near freezing to minimize loss of product. For example Acetic Anhydride could be harmful is inhaled in large amounts. Stir to dissolve it completely, and then add 5 mL of warm 70°C deionized water. Interpretation of results - comparison of retention factors -Has a smooth side and a rough side. We could have accidentally boiled off some of our product. Shape of aspirin depending on the size and dosage in industry? After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in the solution as well as some sulfuric acid, aspirin, and acetic acid.
Raise the temperature of the hot plate to 125 degrees Celsius so that the solution boils. A larger amount of the substance was isolated in 1829 by Henri Leroux, a pharmacist. It is recommended for arthritis and related arthritic conditions, myocardial infarction prophylaxis. Assuming you haven't lost too much of your salicylic acid, add about 10 mL of water to the beaker still containing the crystals for every gram of salicylic acid you expect to obtain, as we are going to recrystallize it. At high temperatures, it behaves like alcohol! 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. Transfer the product to the watch glass.
The phenol test was to test the purity of the aspirin product that was created during the experiment. The reaction that takes place in this reaction is a 1:1 mole ratio reaction. Crystals will reform as the solution cools. Test a small amount of the product for the presence of unreacted salicylic acid using the ferric chloride solution. If none of the solid dissolved at room temperature, heat the tube.
Solubility Aspirin is only slightly soluble in water and acidic solutions such as is present in the stomach. Boil the water until you are sure that all of the salicylic acid has dissolved, then slowly cool the beaker, and finally chill it in a refrigerator or ice bath. The third factor that caused a low percent yield of our purified product was that when we vacuum filtered our purified product, some of our purified product fell through the filter and into the side arm flask. Compounds B and C both experienced a color change, though B experienced a stronger one, so it was not possible to distinguish them using the ferric chloride test alone. This method of forming acetylsalicylic acid is an esterification reaction.
This could have been a reason as to why the yield was not very accurate. Add hot water until the solution turns cloudy. Test this crude product for the presence of unreacted salicylic acid using the ferric chloride test. The sample should have been slowly cooled to 0 ˚C by placing it in a refrigerator and slowly lowering the temperature. Section I — Procedure: summarize the procedure using a flow chart format. Comparing the theoretical yield with the actual yield produced, the quality of the experiment carried out will become evident. The second part of the experiment was recrystallization.