Almost all solids are more soluble in a hot than in a cold solvent, and solution crystallization takes advantage of this fact. Amount of water added to solution K; indentified as polymorphic form IV by DSC; Uncertainty assigned by TRC = 6. Temperature range of purified(recrystallized) sample The procedure performed in our experiment involved chemically reacting salicylic acid and acetic anhydride in order to form acetyl salicylic acid.

Chim., 1916, 14, 174. Also, during the procedures, one should remember to avoid skin contact while handling acetic anhydride and sulfuric acid. But only 1.57g of aspirin was gotten by the end of the experiment. Also, since it was determined that the aspirin gotten at the end was quite pure, we can say that from the 1.57g of the aspirin, it is very likely that majority of the product is pure. Stir and rub mixture to induce crystallisation. This whole step must be done in the fume hood. [all data], Kofler and Sitte, 1950 Since its isolation in 1897 aspirin has been used widely to treat a variety of ailments and diseases. Aspirin, an acetyl derivative of salicylic acid, is a white, crystallize, weakly acidic substance, with a melting point of 136oC and a boiling point of 140oC (Meyers, 2007). When comparing the data obtained for the crude and recrystallized aspirin samples one can conclude that steps that increase purity lead to a reduction in actual yield. H�b```f``j��x����������I���0����y��l9)�B��^� x�>�DrM���R�� ��N���љ�#j��j�_p�A)蘓P�kM���x{>9�c��@��2�GB&zH&� InChI=1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12), National Institute of Standards and This method of analysis can be used to determine the relative purity of aspirin samples. The dried crystals were weighed together with the filter paper and watch glass. Once the aspirin crystals were dissolved 25mL of deionized water was added to the beaker. ; Shaw, P.,

6 minutes Database and to verify that the data contained therein have Another important observation is that synthesis techniques that increase the purity of a sample also lead to a decrease in percent yield.

The percent yield of the aspirin obtained from my experiment is 46.3% yield. K; by Dahm metho, not ground; Uncertainty assigned by TRC = 2.5 K; by Dahm metho, not ground; Uncertainty assigned by TRC = 0.5 K; Dahms melting point apparatus, Hg-in-glass thermometer, graduated 0.1 deg, calibr. Summers, M.P. Aspirin can be made by reacting salicylic acid with acetic anhydride. 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. Simply put, esterification is a reaction between a carboxylic acid and an alcohol which is catalyzed by a mineral acid which is, in this experiment, sulfuric acid. errors or omissions in the Database. K; by German Pharm. The weight was recorded.

; Herron, C.S., Water is added once removed from heat with addition of cold water and suction filtration is carried out. Synthesis of Aspirin is known as esterification. Chemsrc provides Aspirin(CAS#:50-78-2) MSDS, density, melting point, boiling point, structure, formula, molecular weight etc. G. Chim. 6mL of acetic anhydride is added to the salicylic acid to the flask in the fumehood. Why Management Is Important For Business Business Essay. J. The limiting reactant in this chemical reaction was salicylic acid, with acetic anhydride present in excess in order to react with any water produced during the reaction of the reactants, and thus improve the yield of aspirin. 67oC-78oC If you spill any (even a drop) clean it up immediately using lots of water. The solvent that is used for this is ethanol and water. Sulfuric acid is another dangerous chemical. However, the presence of water in the samples leads to not only inaccurate data but also inaccurate conclusions regarding percent yield, purity of our aspirin samples, and the effectiveness of our synthesis techniques and chosen reactants and catalysts. It is used in polymer industry. This might have affected the results. In addition to the Thermodynamics Research Center When we tested the melting point, the range was 106-118. If you continue to use this site we will assume that you are happy with it. This way, after the impure solid is dissolved in the hot solvent, any undissolved impurities can be removed by filtration.

Technology, Office of Data Aspirin, also known as acetylsalicylic acid (ASA), is a medication used to treat pain, fever, and inflammation.Specific inflammatory conditions in which it is used include Kawasaki disease, pericarditis, and rheumatic fever.Aspirin given shortly after a heart attack decreases the risk of death. K; by differential thermal analysis, peak also obs. J. Pharm. The impurities in our recrystallized sample actually lowered the melting point of the overall sample and widened the melting point range. Aspirin is a derivative of salicylic acid that is a mild, nonnarcotic analgesic useful in the relief of headache and muscle and joint aches. Aspirin, an acetyl derivative of salicylic acid, is a white, crystalline, weakly acidic substance, with a melting point of 136 °C (277 °F), and a boiling point of 140 °C (284 °F). K; by Dahm method, ground; Uncertainty assigned by TRC = 2. New York, NY: McGraw Hill Sneader, W. (2000). Appl., 1920, 2, 291. A. Solvent suitable for this recrystallisation process is a mixture of ethanol and water. There could be problems that might have affected the product of course, such as, when dissolving the initial amount of salicylic acid in the solution of acetic anhydride and concentrated sulfuric acid, it did not completely dissolve into the solution, even when it was being heated. Phase Diagrams of Aspirin- Acetominophen-Urea Systems, When attempting to recrystallize the aspirin, some may have stayed in solution and not crystallized during each of the cooling procedures. Synthesis The synthesis of aspirin is classified as an esterification reaction. Uncertainty assigned by TRC = 12. [all data], Schwartzman, 1972 This solution was mixed thoroughly and then allowed to cool. Monatsh. By continuing we’ll assume you’re on board with our cookie policy, The input space is limited by 250 symbols. This sample had a median melting point temperature of 129oC. K; pre-heated to 120 deg C; Uncertainty assigned by TRC = 2. The scope of this experiment is to examine one of the most common methods of aspirin synthesis and then examine the efficiency of the process and the purity of the samples produced. You can get your custom paper from and Informatics, NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data), Thermodynamics Research Center, NIST Boulder Laboratories, Kenneth Kroenlein director. 1.399g Concludes that aspirin does not exist in polymorphic forms; Uncertainty assigned by TRC = 5. Sulphuric acid is added and heated for a short period to complete reaction. K; identifed as polymorphic form VI 1 by DSC; Uncertainty assigned by TRC = 10. Determining the relative percent yield and attained purities of different synthesis processes is vital to the viability of an affordable commercial product for the aspirin market.

[all data], Summers, Carless, et al., 1970 Acetic anhydride is uses as it is cheap and forms a by-product, acetic acid which is not corrosive and can be recovered to make more acetic anhydride unlike other acetylating agents that also can be used. After removing from heat, 1 mL of distilled water is cautiously added to the mixture while it is hot to decompose the excess acetic anhydride. In lab today, we measured the actual yield and melting point of aspirin that we had made in lab last week. The recrystallized aspirin was dried in an oven and then massed.

Dielectric Constants of Some Organic Compounds Over A Wide Temperature Range, (File Format: Jpg, Gif, Png, PDF,Zip,Txt,doc or xls Max Size: 3MB), The username will be used as the login user name and retrieve the password, Copyright 2017 © ChemicalBook. J. Pharm. As for recrystallisation of aspirin, collected crude product prepared in preparation of aspirin which is impure is dissolved in ethanol and hot distilled water is added to the solution. Reichsanstalt thermometer; Uncertainty assigned by TRC = 0.5 K; Dahm melting point apparatus, Hg-in-glass thermometer, graduated 0.1 deg, calibr.