Aspirin has different chemical features than any other molecules. Caffeine is a trimethylxanthine in which the three methyl groups are located at positions 1, 3, and 7. Pure aspirin has a melting point of 5o, while salicylic acid has a melting point of 157159o. Once it is a liquid, the boiling point is the temperature that the vapor pressure of the liquid is large enough that bubbles form inside the body of the liquid. Fusion melting point data from nist standard reference database 69. Results page 4 about sample apa synthesis free essays. Chemistry 51 experiment 11 synthesis and analysis of aspirin. The melting point range of pure aspirin is 8140 c and the melting point range of the salicylic acid starting material is 158161 c.
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. Generate an infrared spectrum of your aspirin sample your instructor will demonstrate how to use the ft. It might seem strange to have a popular book of more than 300 pages dedicated to just one drug. Ancient asian records indicate its use 2400 years ago. Preparation and recrystallisation of aspirin contents page synopsis iii 1 introduction 1 1. The preparation of aspirin, the recrystallisation of aspirin and the melting point determination of aspirin. Nist chemistry webbook the national institute of standards and technology nist uses its best efforts to deliver a high quality copy of the database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. A melting point depression activity using two inorganic substances. Aspirin simple english wikipedia, the free encyclopedia. The percentage yield of the synthesis was calculated to be 78. In this experiment, you will measure the melting point of your synthesized asa product, salicylic acid, a crushed aspirin tablet, and pure asa from a manufacturer. In the 20th century, scientists discovered many details of aspirin s antiinflammatory and analgesic properties, including its molecular mechanism of action. Jan 10, 2020 for melting point analysis, preparation is straight forward.
For example, the literature melting point of ferrocene, is \172\\174\texto \textc\. Synthesis of aspirin and determination of melting point a. The ir spectrum readings were unreliable because of contamination andor overheating of compound. Results at the end of the experiment, the result gotten should be a result of 40 60 % yield and a melting point that is around the theoretical melting point of aspirin, which is 5ac 6ac. Both experimental successes and errors were analyzed. Range of the melting point indicate the purity of the compound. According to the melting point values the aspirin product.
The aspirin story nearly all of us have used aspirin at some time in our lives, but not many of us know that for hundreds of years a related compound from willow bark has been used to relieve pain and treat fevers. According to the melting point values, the aspirin product does not resemble pure aspirin because the melting point range was off by a little and was a bit too high. As a compounds melting point is a physical constant, it can be used to support the identity of an unknown solid. The first part of the experiment aims to synthesize aspirin from the reaction of salicylic acid with acetic anhydride. Impure compounds normally have lower melting points and broader melting ranges than if pure, even if the impurity would have a higher melting point itself. Aspirin, an acetyl derivative of salicylic acid, is a white, crystallize, weakly acidic substance, with a melting point of 6oc and a boiling point of 140oc meyers, 2007. On the anomalous melting point and the decomposition of acetylsalicylic acid. Due to its wide range, and lower value than that of the theoretical melting point of 6c, it was assessed that the prepared aspirin was impure. Melting point mp is a quick and easy analysis that may be used to qualitatively identify relatively pure samples approximately melting point analysis, as the name suggests, characterizes the melting point, a stable physical property, of a sample in. Determine the melting point of your aspirin sample your instructor will demonstrate how to use the melttemp apparatus. Here are some values from some standard references i have. Percentage yield is worked out by actual yield of synthesised aspirin.
Salicylamide is used in combination with both aspirin and caffeine in the overthecounter pain remedies. Newest meltingpoint questions chemistry stack exchange. Starting in medieval europe, the author explains the origins of aspirin from the willow tree, and recreates for the reader the various ways medieval europeans used the products of nature. The aspirin crystals were observed under the microscope and were drawn on the result sheet. Mar 01, 2007 the problem with getting a value for the melting point of an organic substance is the purity of the material. Salicylamide is the common name for the substance ohydroxybenzamide, or amide of salicyl. Aug 18, 2019 as a compounds melting point is a physical constant, it can be used to support the identity of an unknown solid. If phenol is present in a sample, the resulting color means. Preparation and recrystallisation of aspirin 1796 words 8 pages. Abstract aspirin is the common name for the compound acetylsalicylic acid, widely used as a fever reducer and as a pain killer. Highlighting the historical evolution of the salicylates and the commercial development of. The aspirin had an appearance of a white, needlelike crystalline solid.
A pure sample of a substance will melt at a sharply defined temperature, an impure sample will show a larger range. Even in ancient times, salicylatecontaining plants such as the willow were commonly used to relieve pain and fever. Aspirin has long been established as a useful analgesic and antipyretic. Before coming to lab prelab exercise grading grading for recrystallizationmelting point experiment. The crc handbook of chemistry and physics hbcp contains over 700 tables in over 450 documents which may be divided into several pages, all categorised into 17 major subject areas. Preparation and recrystallisation of aspirin 1796 words. The aspirin story nearly all of us have used aspirin at some time in our lives, but not many of us know.
Caffeines melting point was obtained to be 190230 which was also close to the pure compound melting point. As heat is applied to a solid, its temperature will increase until the melting point is reached. The melting point for aspirin was obtained to be 109 4. Apr 17, 2009 in general will the melting point of an aspirin tablet be higher or lower than that of pure lab made aspirin powder. If impurities are present in your crude sample, the melting point range for your product will be lower than the range of pure aspirin. Usp reference standards are rigorously tested and evaluated by multiple independent commercial, regulatory, and academic laboratories to confirm accuracy and reproducibility. Aspirin is one of the mostused medical drugs in the world. Preparation and recrystallisation of aspirin writework. The point assignments for each portion of the prelab are shown below.
The melting point temperature ranges were 126oc2oc and 129oc4oc for the crude and recrystallized aspirin samples, respectively. The r f values have little significance in determining purity in the aspirin product because all the samples have relatively close results thus not proving the purity content in the aspirin product. Purity can be determined by identify the melting point of aspirin. Melting point tips and guidelinesif the melting point of a pure compound is within a degree of the value found a lab a sample is impure if it has a melting point range that is lower andor wider than below finally at a temperature of 75, all of the solid has aspirin ourmedin the course of his work on the synthesis and properties of. Most of us have used aspirin at some time in our lives, but few will know that a related compound derived from willow bark has been used to relieve pain and treat fevers for over 2,000 years. The melting point of pure salicylic acid is 150 c, the melting point of pure aspirin is 5 c. A compound that contains impurities will tend to melt over a range of temperatures and at temperatures lower than the fixed mp for the pure compound. One of the most brilliant medical historians and journalists of our time, the late roy porter, wrote a book called the greatest benefit to mankind. It is most commonly used as a pain killer, or to reduce fever or inflammation. Preparation of aspirin and determination of the melting point. Only 1 to 3 mm of sample is needed for sufficient analysis.
Aspirin, also known as acetylsalicylic acid asa, is a medication used to treat pain, fever, or inflammation. The melting point of impure organic compounds journal of. For example naphthalene, an ingredient of mothballs, has a melting point of 80c. The objective was to convert a specific amount of salicylic acid into the same amount of aspirin that was high in purity. The sample must be thoroughly dried and relatively pure aspirin had a melting point range of 56.
More heat then will convert the solid into a liquid with no temperature change. Also, your melting point range may be greater than 2 degrees. A purine alkaloid that occurs naturally in tea and coffee. The aspirin waste was discarded in the waste in the aspirin waste container. We offer publicly available, official documentary standards for pharmaceutical ingredients in the usp nf that link directly with a primary reference standard. Sep 21, 2004 this book brings to the light the trials and tribulations of those who helped bring the drug aspirin into being, and then made it into a worldwide commodity. Reviewing over a century of aspirin research and use, aspirin and related drugs provides a comprehensive source of information on the history, chemistry, absorption in the body, therapeutic effects, toxicology, elimination, and future uses of aspirin.
The experimental melting point range of aspirin was determined to be 122 2c. Determination of purity phenols form a colored complex with the ferric ion. The sample must be thoroughly dried and relatively pure melting point analysis capillary tube, which is simply a glass capillary tube with only one open end. A medical history of humanity from antiquity to the present bmj 1998. It also has an antiplatelet effect it reduces the number of platelets in the blood which reduces blood clotting in that function it is used to prevent heart attacks. Melting point, temperature at which the solid and liquid forms of a pure substance can exist in equilibrium.
Synthesis of aspirin lab chem 165 linkedin slideshare. This book contains eight freestanding activities that can be used singly or as a coherent package in a wide range of teaching and learning situations for both academic and vocational courses. Use water bath or electric heater or sand bath for heating. Furthermore, the other objectives were to enable students to conduct the synthesis of aspirin, reinforce skills or recrystallisation and the technique of melting point determination. To find out the purity of aspirin obtain by recrystallisation of prepared aspirin from reaction of salicylic acid with acetic anhydride. Perhaps a more meticulous experiment can increase the yield of aspirin. The melting point can be looked up in a reference book this value would then be called the literature melting point, and compared to the experimental melting point.
Bulletin of the chemical society of japan 1950, 23 1, 2325. Experimental synthesis of aspirin and melting point purity. Compare the melting point you recorded to the melting point in the literature. Miscellaneous the melting point of acetylsalicylic acid published by permission of the chairman of the committee of revision, u. You can also buy a copy of this book via the royal society of chemistry online shop for. The purity of sample was tested by determining its melting point range. The melting point is the temperature in which aspirin will go from a solid to a liquid. Batches of highly purified chemicals, intended for use as reference substances in the calibration of apparatus for melting point determinations, have been subjected to a collaborative assay by 15 laboratories in countries. Aspirin is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antiinflammatory compound that inhibits cox1.
For melting point analysis, preparation is straight forward. The search on this page works by searching the content of each page individually, much like any web search. Reduce the sample to a fine powder by using mortar and pestle. The documented value for the melting point of pure aspirin is 5 degrees celsius. Fecl 3 color test for phenols another test on the purity of the final product is the very sensitive test for phenols given by fecl3. Results and conclusion for aspirin synthesis essay. The synthesis of aspirin is classified as an esterification reaction.
When the aspirin was prepared, it was isolated and filtered. Our recrystalized aspirin product had a melting point range of 110. Since we only have a limited number of melting point apparatuses, some of you should do the sublimation first and melting point second. Aimed at post16 students in chemistry, this book contains activities for both academic and vocational courses. The melting point of a pure aspirin sample should be within 1c of its known melting point.
C, but had a quite a wide range which could be due to impurities present. For example, the literature melting point of ferrocene, is. A melting point capillary tube with 12cm depth of fine crystals was loaded. Aspirin melting point essay medicine and health articles. Aspirin, an acetyl derivative of salicylic acid, is a white, crystalline, weakly acidic substance, with a melting point of 6 c 277 f, and a boiling point of 140 c 284 f. Preparation and recrystallisation of aspirin research. The melting point range of the created product 1262 degrees celsius was lower than that for pure aspirin 1205degrees celsius. Pittsburgh pa section on practical pharmacy and dispensing, a. It has a role as a central nervous system stimulant, a ryanodine receptor modulator, an ec 3.
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