Synthesis of Aspirin Essays

Synthesis of Aspirin Essays Synthesis of Aspirin Essay Synthesis of Aspirin Essay Essay Topic: Synthesis Sypnopsis In this experiment, acetylsalicylic acid was synthesized from the acidification of salicylic acid and acetic anhydride. The objective was to convert a specific amount of salicylic acid into the same amount of aspirin that was high in purity. 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. The amount of each compound should be the same because there is a 1:1 ratio between them. The purity of the synthesized aspirin was measured by determining its melting point and percent yield. Soluble impurities increase the range over which a compound melts and often decreases its overall melting point temperature1. If the experiment went as expected, a pure sample of aspirin with a high percent yield would have been obtained. The percent yield obtained was 56. 1% and the melting point was 134. 7- 136. 8. Introduction Aspirin (acetylsalicylic acid) is a versatile drug that is consumed in huge quantities worldwide. It is a non-steroidal anti-inflammatory drug (NSAID) with a wide range of physiological effects. The first discovery of aspirin occurred in England, in 1963, believing that the bark of willow trees with a beneficial effect in alleviating distress due to fevers, aches, and pains2. Salicylic acid was later extracted from the willow bark and it proved to be an active ingredient. Salicylic acid was synthesized from basic starting materials by 1860 which was helpful to the medicinal field but there were some problems2. Salicylic acid turned out to be irritating to the membranes of the throat, mouth, and stomach. The product had a high acidity of the compound but fortunately, successful amendments were done, namely, the replacement of the acidic phenolic hydrogen atom with an acetyl group. In 1893, a effective synthesis of acetylsalicylic acid was created, patented in 1899, commercialized under the trade name of ‘aspirin’ by the Bayer Company in Germany3. The name ‘aspirin’ was invented by the chemist, Felix Hoffman, who originally synthesized acetylsalicylic acid for Bayer3. At very low doses, aspirin is used to treat and prevent heart attacks and blood clots. At higher doses, it is used as an analgesic to reduce pain and as an antipyretic to reduce fever. At very high doses, it is an effective anti-inflammatory agent used to treat rheumatic fever, gout and rheumatoid arthritis. It is also an anticoagulant, it dissolves corns and calluses, and it provokes loss of uric acid (a toxin) but promotes retention of fluids in the kidneys. It kills bacteria and induces peptic ulcers. When ingested, acetylsalicylic acid remains intact in the acidic stomach, but in the basic medium of the upper intestinal tract, it hydrolyzes forming the salicylate and acetate ions. When ingested, acetylsalicylic acid remains intact in the acidic stomach, but in the basic medium of the upper intestinal tract, it hydrolyzes forming the salicylate and acetate ions. The exact mechanisms of its pharmacological actions are still under study. In many plants, salicylate can induce flowering. However, aspirin may cause side effects for example, nausea, vomiting, stomach pain and heartburn. Theory Aspirin is prepared from salicylic acid and acetic anhydride with the help of an acid catalyst. Concentrated sulphuric acid acts as a catalyst. After preparation, the product is purified. This is especially important for chemicals that are used as food additives and pharmaceuticals. The most common method of purifying solid organic compounds is by recrystallization. When an impure solid compound is dissolved in a solvent, it is then allowed to slowly crystallize out as the solution cools. As the compound crystallizes from the solution, the molecules of the other compounds dissolved in solution are excluded from the growing crystal lattice, giving a pure solid. Crystallization of a solid is different from a precipitation of a solid. In crystallization, there is a slow, selective formation of the crystal framework resulting in a pure compound. In precipitation, there is a rapid formation of a solid from a solution that usually produces an formless solid containing many trapped impurities within the solids crystal framework. For this reason, experimental procedures that produce a solid product by precipitation always include a final recrystallization step to give the pure compound. Figure: The esterification of salicylic acid by acetic anhydride5. The -OH group of salicylic acid that reacts with acetic anhydride to form an ester-like product. The carboxylic acid group of salicylic acid remains unchanged. Acetic anhydride is used because it is cheap and forms a by-product, acetic acid. Acetic acid is non corrosive and can be recovered to produce more acetic anhydride. Procedure 2. 4g of salicylic acid was weighed and poured into a 100ml conical flask. The actual weight was then recorded. In the fume hood, 6ml of acetic anhydride was added to the salicylic acid in the flask. To this mixture, 3 to 4 drops of sulphuric acid was added, swirled to mix and then heated in a water bath for 10-15 minutes to complete the reaction. The mixture was removed from the water bath while it was still hot and then 1ml of distilled water was added from a dropper carefully to decompose the excess acetic anhydride. An additional 40ml of cold water was added and stirred with a stirring rod to induce crystallisation. The crude product was collected by suction filtration and washed with a little cold water. The crude product is relatively impure; hence it was needed to be purified by recrystallisation. A solvent suitable for this recrystallization process would be a mixture of ethanol and water. The crude product was dissolved in approximately 5ml of ethanol in a 100ml conical flask and heated on a hot plate. To the solution, 30ml of hot distilled water was added in. The solution was then warmed till all solid has dissolved. The solution was allowed to cool. A clean, dry watch glass together with a filter paper was weighed and the weight was recorded. The recrystallised product was obtained by suction filtration using the weighed filter paper. The crystals and filter paper was transferred onto the weighed watch glass and dried in to the oven (100Â °C) for 15 to 20 minutes. The crystals, filter paper and watch glass are then placed in desiccators for 5 to 10 minutes. The dried crystals, together with the filter paper and watch glass were weighed. The weight was recorded and the weight of dried, recrystallised aspirin was calculated. The expected yield of aspirin was calculated from the amount of salicylic acid used. The percentage yield of dried, recrystallised aspirin was also calculated. The melting point of aspirin was determined. Results Mass of salicylic acid Mass of filter paper and watch glass Mass of dried, recrystallised aspirin, filter paper and watch glass Mass of dried, recrystallised aspirinMass of dried, recrystallized aspirin, filter paper and watch glass Mass of filter paper and watch glass Percent yield Number of moles of salicylic acid used (mol wt of salicylic acid = 138) Expected number of moles of aspirin Expected mass of aspirin Percent yield Melting point Temperature Range134. 7 – 136. 8 Appearance The crystals are white and shiny, shaped needle-like. The crystals resemble glass wool. Discussion The results and calculations shows how much acetylsalicylic acid was synthesized compared to how much salicylic acid was used. Since there is a 1:1 ratio between the two, then the amount of salicylic acid used should be equal to the amount of acetylsalicylic acid recovered at the end of the experiment. As the result shows, this is not the case, for 1. 83g of acetylsalicylic acid was harvested when 2. 40g of salicylic acid was used. This could have some effect on the purity; for the melting point of the harvested acetylsalicylic acid which is 134. 7 – 136. 8 was not very close to the theoretical melting point. The percentage yield is only 56. 1%. Since the final product was determined not to be very pure, it is highly likely that less than 1. 83g of the product was acetylsalicylic acid. Further analysis of the product will have to be done to determine exactly how pure the product actually was. There were several problems that could have contributed to the low purity or mediocre percent yield. When dissolving the initial amount of salicylic acid in the solution of acetic anhydride and concentrated sulphuric acid, it did not completely dissolve into the solution, even when it was heated. There could also be loss of product on the filter paper. Some crystals would be stuck onto the filter paper and this might have affected the mass of the crystals. The sample may not have been completely dried out before weighing. This could have a slight impact on the results of the overall yield of aspirin because it was possible that not all of the salicylic acid was synthesized. To determine if this affected the synthesis of aspirin at all, the experiment should have been ran a second time to see if the same thing occurred. Conclusion The experiment did not go completely as expected. The reaction yielded only 56. 1% of its expected product. The purity of the aspirin was not very high, because there might be impurities in the acid used. Reference 1. Henry, Dr. Geneive. 2004. Susquehanna University. Synthesis of acetylsalicylic acid (aspirin). 2. The history of Aspirin, accessed 25th May 2009, 3. History of Aspirin, viewed on 13th Dec 2010, ; http://inventors. about. com/library/inventors/blaspirin. htm; 4. Theory, accessed 15th Dec 2010, 5. Dr. Carman. 2002. University of Nevada, accessed, 15 Dec 2010, ; http://tooldoc. wncc. nevada. edu/aspirin. htm; 6. Synthesis of Aspirin, accessed 13th Dec 2010, 7. Aspirin, accessed 14th Dec 2010,

Kin Words

Kin Words Kin Words Kin Words By Maeve Maddox The other night a local television anchorman, not noted for a large or literary vocabulary, surprised me with the following: I feel such a kinsmanship with these survivors. The anchor’s sentiment was kind, but kinsmanship is out of place in modern English. Kinsmanship has an entry in the OED, and Emily Dickinson (1830- 1886) used it. It shows up on the Ngram Viewer, but at a minuscule percentage compared to the far more common kinship. And Word’s spellchecker underlines it in red. It’s safe to say that kinsmanship has been replaced by kinship as the modern English word to describe a sense of fellow feeling. A kinsman is â€Å"a blood relation,† but the word is not common in ordinary speech. It has a literary feel, as in the title Two Noble Kinsmen. Both kinsman and kinship derive from the same Old English noun: cynn, a word with several meanings, one of which is â€Å"people related by blood.† From the same word we also get kind in the sense of class or group. Kinship is what one feels for people with whom we identify in some way, people who are of the same kind as we. Here are some recent uses of kinship on the Web: Quecreek  survivor feels kinship  with Chile miners.   When two  firefighters  meet for the first time, they will  feel  a  kinship  with each  other that transcends many other examples of mutual hobbies or interests. Why do so many feel a connection - be it kinship or competition - with utter strangers just because they share a name? Kids who’ve lost limbs find kinship at Camp No Limits on Lake  Coeur  d’Alene The nouns kin and kinfolk refer to people related by blood ties: I had, it seemed to me, hundreds of kin- aunts, uncles, cousins, second cousins- near the small town of Oak Hill, Ohio. By adolescence, â€Å"what to do with Eleanor† began to concern her Roosevelt kin. Arab immigrants are bound to each other by strong  family  ties, and most want to live and work  close  to  kin.   While Arthur was serving in the New York militia during the conflict, his wife privately sympathized with the Confederacy, for which many of her Virginia kinfolk were fighting. A qualitative approach was used to look into the experiences of male caregivers in offering to look after kinfolk with harsh psychological sickness. The expression â€Å"next of kin† means â€Å"the closest living relative† and is often used in a legal context: Historically, the next of kin have exercised proprietary rights in the control of dead bodies. If the person is under 18, the parent, legal guardian, custodian or next of kin may have authority to apply on the person’s behalf. Police are withholding the name of the deceased, pending notification of next of kin. Finally, the idiom kith and kin means friends and family. The noun kith is related to the archaic adjective couth, known or familiar. Kith are people one is acquainted with. Here are examples of this idiom: People helped each other and expected help in  return. This included soldiers who assumed  kith and kin  would help the wives and children they left behind. As the album title suggests, Selways songs are laced with references to his  kith and kin. I had  neither kith nor kin  in England, and was therefore as free as air.   â€Å"Mind you,† said the  old man, â€Å"even if I make good on this reef, Ive  neither kith nor kin to leave my money to.   Note: Kin is frequently used alone, but kith seems always to be linked to kin Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Vocabulary category, check our popular posts, or choose a related post below:Regarding Re:25 Russian Words Used in English (and 25 More That Should Be)Sentence Adverbs

Critically evalutate the evidence that criminal profiling is effective Essay

Critically evalutate the evidence that criminal profiling is effective - Essay Example It is usually carried out in a three stage process: â€Å"First, police officers collect crime scene data and forward it to a profiler; second, the profiler conducts an analysis of the crime scene data; and third, the profiler provides predictions about the type of individual likely to have committed the crime in question.† (Snook et al,, 2007, 438) There was initial enthusiasm for this approach, especially in the United States where the FBI set up a special ‘Behavioral Science Unit’ which analysed crimes and made recommendations for the application of criminal profiling in serious crime cases. From the beginning it was clear that the process involves multiple skills and multiple agencies, being a technique that combines elements of both art and science (Cook and Hinman, 1999, 230) and crosses over traditionally constructed professional boundaries. There has been discussion about some of the tensions arising from this multi-disciplinarity, and the gulf between res earchers and practitioners. (Alison et al, 2004). Critical opinion on the practice of criminal profiling has been mixed, ranging from positive evaluations to serious doubts as to whether criminal profiling is any more valuable than common sense. This paper reviews the underpinning theories behind criminal profiling, discusses its methodologies and the problems that can arise in its use, and then finally evaluates its effectiveness. Theories behind criminal profiling. Psychology is the major science behind criminal profiling and its origins can be traced back to the beginning of the twentieth century: â€Å"the inferring of general characteristics of a person on the basis of a limited amount of information about them, has scientific roots in psychometric testing.† (Canter, 2000, p. 3) This in turn is based on a large body of research into the variation that exists between individuals. Psychologists searched for ways of isolating small individual features which, when considered together and against a large database can predict with some degree of accuracy what type of personality a person has and how they are likely to behave in different situations. The predictions are inferred, which means they start with what is known, but move into speculation based on a number of different areas of knowledge including past experience and databases collected and collated over the years. The so-called â€Å"homology assumption† asserts that â€Å"criminals who exhibit similar crime scene actions have similar background characteristics.† (Doan and Snook, 2008, p. 61). In practice this means that investigators in a case of rape, for example, will go on the assumption that there is â€Å"a positive linear relationship between the similarities of the crime scene actions and the corresponding similarities in the background characteristics for a sample of rapists.† Any inferences that are made are deliberately not absolute statements, but are based on li kelihood and similarity: â€Å"It’s certainly possible for some characteristics to be consistent or homologous, and indeed this can be demonstrated in some cases. However, it is not a reasonable assumption in every case or even in most cases.† (Turvey, 2008, p. 540) Additional factors such as drug or alcohol use and mental illness with or without adequate medication can affect the offender’s behaviour in unpredictable ways, causing a depart at times from his or her enduring characteristics. Because of these variables, some of which cannot be known by

The battle of Trenton Essay Example | Topics and Well Written Essays - 250 words

The battle of Trenton - Essay Example In fact this war served as a morale booster and gave immense confidence to the American army to continue the American revolutionary war even though American army suffered lot of setbacks earlier. One of the major significances of this war is the fact that it occurred in the Christmas night. Hessians and British troops never thought that American army may attack them on that particular day. Moreover, they never anticipated that American troops may try to cross the Delaware River under difficult and risky conditions. However George Washington took the risk of crossing this river using some boats even though the river was filled with ice blocks. British troops and the hessians were taking rest or sleeping while American troops arrived quite unexpectedly. More than one hundred British and hessians soldiers were killed in this battle and the rest were captured live. Not even a single American soldier was killed in this

Was in my final year at high-school Essay Example for Free

Was in my final year at high-school Essay I was in my final year at high-school. I was only seventeen and the pressure of knowing that the outcome of school results would determine my whole life ahead finally got to me. I snapped. One day, in the absence of my parents, I ran away from home, hoping never to return. This was the turning point in my life. With an incomplete education on one hand, I was a lost soul, unaware of what to do or where to go. I ran into a group of people who claimed they could assist me out of this dark web I was now tangled in. They introduced me to drugs. Dosed with pills of heroin and cocaine, my life was tumbling downhill like a snowball, only gathering wrong as it rolled. It was those times where I was not even aware of what I was doing until I slept and then craved for more of the vile drugs I had already once ingested. I was a rogue who lived by my wits in a corrupt society. I had no contact with my real family and over time, these people became my new family. They led me to commit a chain of robberies, homicidal attacks a chain of crimes. Day by day, I became a wanted criminal. No conscience made me look back; I was not overshadowed by my guilt. It was only a matter of time before I was caught and sentenced to nineteen years of imprisonment. The words of Gregory David Roberts described my situation as I felt it- I was a revolutionary who lost his ideals in heroin, a philosopher who lost his integrity in crime and a poet who lost his soul in a maximum-security prison. Two years in jail and I escaped in broad daylight and took asylum in the jhopadis of Dharavi in Mumbai. I got involved in the mafia and started a business of smuggling guns and ammunition and counterfeiting money. The money I earned was enough to pay off any heart fancying a call to the police. I was a notoriously known figure now, and probably the most wanted person in the whole of the country. Everyday I met new people interested in my business. One day to my surprise a female entrepreneur came to my office. She was gorgeous and from the moment I set my eyes on her I fell in love with her. She helped my business for six months and became a close part of my life until finally she betrayed me to the police. It seemed she was involved with them and did this for a sum of money. I was imprisoned again. It was here that I was chained beaten, stabbed and starved. I was at constant war with myself. Should I have done what I did? But it did not matter now. My companions lost sanity while I kept my nerve. I buried them and their lives into my own as it was only with their help that I was still alive. I realized through the pain and sufferings within, that even in my brutal, gory helplessness, I was still free- to hate those who were torturing me, or to forgive them. It may not have been everything but in times like those, it was all I but and it seemed like a whirlpool of possibilities. This hardest choice I thought, could determine where I may end up next and I chose to forgive. Time flew by and the nineteen years of torture soon ended. I thought and reflected upon my half-life as it began back in high-school. I thought of what I could have been- a better human being. Pondering over the thought that a life wasted is not worth living, I realized that it was time to turn over a new leaf. I penned my experiences and memories in an autobiography to ensure that young adults would make the right choices in life and would not fall in the same trap as I did. My book- Realization- as it is titled is a guide for youngsters today and has earned me fame. My life has changed ever since. Life now seems beautiful. I regret having ruined a long part of, what could have been, a fabulous journey throughout. It was an expensive realization

Political History of Global Warming Essay -- Global Warming Climate Ch

Political History of Global Warming There is a lot of ambiguity surrounding the theory of 'global warming' and the proper political response to it. At the very center of the scientific debate on the variability of global climate is to what extent human activities influence climate change. Another unforeseeable is whether the potential impacts of climate change will be harmful or beneficial for humans, managed agriculture, and natural ecosystems. Some question the authority with which current scientific data has been given in international negotiations on the regulation of greenhouse gases. Others are convinced that immediate actions must be taken to limit the potential effects of excess greenhouse gases released into the atmosphere since the beginning of the industrial era. It would be difficult to credit a single event that encouraged the U.S. Government to begin a major program to investigate global climate change; instead it would best be explained as a long series of events, mostly in response to the international attention given it. The idea that excess carbon dioxide in the atmosphere could trap heat in Earth's atmosphere was first put forward in 1898 by Swedish physicist Svante Arrhenius. But it wasn't until the late 50s that scientists within U.S. federal agencies started to participate in scientific workshops, international conferences, and international scientific research that explored the nature of Earth?s climate system and the role of carbon dioxide (CO2) and other greenhouse gases believed to modify it. In 1965 the President?s Science Advisory Committee issued a report, Restoring the Quality of Our Environment, that identified climate change and CO2 buildup as deserving expanded monitoring and study. The... ...nal Climate Program Act, P.L. 95-367, 15 USC Â §2901 et seq., Revkin, Andrew C., and Katharine Q. Seelye, ?Report by the E.P.A. Leaves Out Data on Climate Change,? New York Times, 6/19/2003, Vol. 152 Issue 52519, pA1, 0p. Rowe, Richard, and Larry Jeffus. The Essential Welder: Gas Metal Arc elding Classroom Manual. Albany:Delmar, 2000. Suraje, Dessai, and Nuno S. Lacasta, Katharine Vincent. International Political History of the Kyoto Protocol: from The Hague to Marrakech and Beyond, International Review for Environmental Strategies Vol. 4, No. 2, pp. 183 ? 205, 2003 United Nations Framework Convention on Climate Change. 2006. United Nations. April 2nd, 2006. U.S. Global Change Research Information Office. 2002. Department of State: Bureau of Oceans and International Environmental and Scientific Affairs. April 2, 2006.

Oniomania: Psychology and Higher Income Levels Essay

This condition generally interferes with the functioning of an individual where an individual is faced with an overwhelming urge to shop. Signs include; someone being overly preoccupied with shopping (shop till you drop), excessive shopping of especially items that are not used, which eventually leads to debts, marital problems with the spouse, or even other family members such as parents. Other signs include; thinking excessively about money, feeling a rush of euphoria and anxiety when shopping, and ultimately lying about purchases made.(Krueger 1988) How it starts Oniomania has no direct cause, since there is no specific pattern to the way of life of the people who have been diagnosed with as being shopoholics. Some Psychologists speculate that this condition might generate from developmental neurobiological and cultural influences, thus early life influences such as sexual abuse might be some of the cause. It should also be noted that this condition is mostly common in the developed world, probably because of higher income levels thus more of the disposable income and a higher ease of access to credit facilities. Oniomania is also higher in women as compared to men, with a survey in the USA revealing that of those people that were diagnosed with the condition 80% were women.(Lawrence 1990) Advantages The biggest beneficiaries of shopopholism are the retailers who benefit with increased sales especially during the festive seasons. Shopoholics on the other hand benefit to some extent by having a wide variety of items that they bought to choose. They also feel elated in the experience of shopping and hide from the problems in their lives, and some even feel more gratified than even being in a relationship. It should be noted however that these benefits ultimately lead to bigger problems. Disadvantages Advantages include; financial loss, incurring huge debts, family breakdown, loss of friendships and poor work performance caused by loss of time. One can also revamp into theft and psychological trauma. How to stop it Compulsive spending may come with a host of other disorders, which include; alcoholism and eating disorder. It is important for someone who bears the symptoms to seek counseling. Works cited Roberts JA, Tanner JF Jr. Compulsive buying and sexual attitudes, intentions, and activity among adolescents: an extension of Roberts and Tanner (2000). Aboujaoude E, Gamel N, Koran LM. A 1-year naturalistic following of patients with compulsive shopping disorder. J Clin Psychiatry. 2003