This essay sample essay on synthesis of aspirin offers an extensive list of facts and arguments related to it. Your experiment may have some unisolated variables, such as calibration of temperature measurement equipment and also you will have errors. Salicylic acid is extremely bitter tasting, and frequent use can cause severe stomach. Preparation and recrystallisation of aspirin contents page synopsis iii 1 introduction 1 1. Although the salicin in willow bark has analgesic properties, purified salicylic acid was bitter and irritating when taken orally. Organic chemistry students determine the melting point of samples. Preparation and recrystallisation of aspirin 1796 words 8 pages. Before the melting point was determined if one crystal sample contains methanol due to incomplete solvent removal, and the other crystal sample contains water by absorbing moisture in the air what effect could these have on the observed melting points from the two samples. Now do titration of the samples stored after each recrystallisation. Caffeine is a trimethylxanthine in which the three methyl groups are located at positions 1, 3, and 7. Aspirin given shortly after a heart attack decreases the risk of death. If the aspirin crystals were not completely dried before. 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. The temperature at which a solid melts is known as the melting point mp of that substance.
To use the concept of melting points for identification and characterization of organic compounds. State two observations during this melting point determination, that would indicate that the sample is not pure. Answer to a pure aspirin has a melting point of 56c. The melting point of the experimental aspirin sample will be identified using a melting point apparatus which will act as the indicator to justify the purity of the sample. These properties include the melting point and boiling point.
Record the first temperature of the melting range with the. Acetylsalicylic acid is weakly acidic substance with a melting point 6c. Introduction in this laboratory you will identify an unknown compound by using mixture melting points. You will mix iron iii nitrate with salicylic acid in your aspirin sample to complex the salicylic acid, which is a bluishpurple colour. Now determine the melting point of commercial aspirin your synthesis converted most, but not all, of the salicylic acid into acetylsalicylic acid. Acetylsalicylic acid, european pharmacopoeia ep reference standard. Find, read and cite all the research you need on researchgate.
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. In practice, a solid usually melts over a range of temperatures rather than at one specific temperature. Pdf crystallization and morphological characteristics of acetyl. 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. Aspirin rsc education the royal society of chemistry. Aspirin synthesis lab report by eddie zhang on prezi.
The melting point of a compound is the temperature at which the solid phase and. Specific inflammatory conditions which aspirin is used to treat include kawasaki disease, pericarditis, and rheumatic fever. Preparation of aspirin and determination of the melting point. Determine the percentage of aspirin acetylsalicylic. Properly fill and use a capillary melting point tube. The melting point is a physical property of a solid and can be used to help identify a substance. Predict a melting point if you combined and mixed 10 mg each of the three reference samples. Bulletin of the chemical society of japan 1950, 23 1, 2325. Experimental synthesis of aspirin and melting point purity. It has a role as a central nervous system stimulant, a ryanodine receptor modulator, an ec 3.
Laboratory 1 melting points and mixture melting points. Pdf preparing a pure aspirin acetylsalicylic acid researchgate. Suggest why a pure sample of aspirin may sometimes appear to. Chemistry aspirin lab question wyzant ask an expert.
Then, read through sections 1 and 2 of chapter 3 describing the prelab writing format with examples. Stepbystep procedures for melting point determination. Also, the literature value is obtained under strict lab conditions. You may find information in reference books, in libraries, in pharmacies and by. Describe briefly how you would determine an accurate value for the melting point of this aspirin. 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. Insert the capillary tube containing the sample into the melting point apparatus. 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. You can also buy a copy of this book via the royal society of chemistry online shop for. Before the melting point was determined if one crystal sample contain. Lab 2 recrystallization 31057 organic chemistry ilab.
In the next activity you measure the melting point of your sample before and. 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. If impurities are present in your crude sample, the melting point range for your product will be lower than the range of pure aspirin. If another melting point trial is to be performed directly after the first, the metal block should be rapidly cooled to at least \20\texto \textc\ below the next melting point by touching it with wet paper towels figure 6. It also helps to know the source of the information some sources are more rigorously researched than others. Range of the melting point indicate the purity of the compound. A purine alkaloid that occurs naturally in tea and coffee. Determine accurate melting point ranges for a wide variety of organic. Sypnopsis in this experiment, acetylsalicylic acid was synthesized from the acidification of salicylic acid and acetic anhydride. 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.
To check the purity of the aspirin the student determined its melting point. This sample had a median melting point temperature of 129oc. 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. The melting point of the experimental aspirin sample will be identified using a melting point. The melting point of the aspirin was found to be 110115. The search on this page works by searching the content. Using recrystallisation improve the purity of aspirin biology essay. The median melting point temperature of this sample was 1. Different substances tend to have different melting and boiling points, and any pure substance will have a specific melting and boiling point. Glass capillaries are used to determine the mixed melting point. Aspirin melting point essay medicine and health articles. When we tested the melting point, the range was 106118. One of the compounds used in the synthesis of aspirin is salicylic acid, which is itself a pain reliever that was known to many ancient cultures, including the native americans who extracted it from willow tree bark. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Aspirin is also used longterm to help prevent further heart attacks, ischaemic. Sample name material weight melting point range actual temperature of melting impure acetanilide mixture 1. A pure sample of a substance will melt at a sharply defined temperature, an impure sample will show a larger range. There are a variety of methods by which a samples melting point can be measured, with the. The recrystallization and dissolution of acetylsalicylic acid ubc. The aspirin crystals should be firmly packed, and fill the capillary tube to a depth of no more than 12 mm. On the anomalous melting point and the decomposition of acetylsalicylic acid. First, read through the introduction and all the experimental sections given in this chapter. 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. If the expected melting point of the compound is not known, heat the sample at a medium rate the entire time and determine an approximate melting point. A melting point capillary tube with 12cm depth of fine crystals was loaded. Aspirin, also known as acetylsalicylic acid asa, is a medication used to reduce pain, fever, or inflammation. The problem with getting a value for the melting point of an organic substance is the purity of the material. In lab today, we measured the actual yield and melting point of aspirin that we had made in lab last week.
Aspirin british pharmacopoeia bp reference standard synonym. Melting points university of massachusetts amherst. The melting point range of pure aspirin is 8140 c and the melting point range of the salicylic acid starting material is 158161 c. Fusion melting point data from nist standard reference database 69. The melting point temperature ranges were 126oc2oc and 129oc4oc for the crude and recrystallized aspirin samples, respectively. Hence, the depression of the melting point of individual crystals is related to.
Dont heat too fast aspirin is used to relieve pain, reduce inflammation, and lower fever. Start studying chemistry isa 2 past papers learn vocabulary, terms, and more with flashcards, games, and other study tools. You are provided with a small sample of pure aspirin in a melting point tube. Also, your melting point range may be greater than 2 degrees. Therefore, be forewarned that the prelab is quite extensive and because its your first one, will probably take about two hours to do. Since the melting point of pure aspirin is 8140, this means that our aspirin was. The experimental melting point range of aspirin was determined to be 122 2c. It is particularly used for organic compounds, where a sample with a known identity and melting point is mixed with an unknown purified sample to determine the melting point. Mixed melting point is a technique used to identify chemical compounds. Take some of aspirin for each sample and leave some in the test tube for testing the melting point. The preparation of aspirin, the recrystallisation of aspirin and the melting point determination of aspirin. Aspirin originally was derived by boiling the bark of the white willow tree. Depending on the impurity material, it could lower or higher the melting point, in your case it is making it higher. Record the temperature where the melting point is first observed and when it becomes a liquid completely.