Tuesday, January 28, 2020
Esterification of 4-methyl-2-pentanol and Acetic Acid
Esterification of 4-methyl-2-pentanol and Acetic Acid Joseph Nuernberg Esterification of 4-methyl-2-pentanol and Acetic Acid by Reflux and Distillation and Characterized by Infrared Spectroscopy Abstract: The objective of this lab was to successfully synthesize an ester from an alcohol and acetic acid. This experiment used 4-methyl-2-pentanol with excess acetic acid to produce (1,3-dimethylbutyl) acetate as seen in Figure 1. The mixture of acetic acid with 4-methyl-2-pentanol and sulfuric acid was refluxed, extracted, distilled and identified using IR spectroscopy. The ester had a fruity smell when obtained. The mass of the final product was 0.582g which gave a 34.6% yield. The results obtained indicated that the final product attained was the ester (1,3-dimethylbutyl) acetate due to the similar bond groups of C=O and sp3 C-H. The reason why the percent yield was low was because the nature of the reaction itself formed ether and ester and some product was lost through extraction. For future experiments, the process must be done a lot quicker in order to ensure the least amount of product evaporates. Introduction: Often in chemical labs, esters are artificially synthesized in order to produce an imitation of a flavor. An ester can be synthesized by the reaction of an alcohol with a carboxylic acid. In this experiment, (1, 3,-dimethylbutyl) acetate was formed through excess acetic acid and 4-methyl-2-pentanol as seen in Figure 1. The limiting reagent in this reaction is 4-methyl-2-pentanol so the theoretical yield of the ester product is dependent on 4-methyl-2-pentanol. Figure 1: Reaction of 4-methyl-2-pentanol with excess acetic acid For this reaction, the reflux will be utilized. Heat is applied with a boiling chip, to allow the reaction to occur. The vapor rises and escapes from the round bottom flask and is then cooled by the water condenser. The vapor turns back into a liquid and drips back into the bottom flask. In order to remove certain compounds, the synthesis involved extraction to isolate compounds. The denser layer or the aqueous layer will be at the bottom and can be removed with a pipette. The product of ether and ester was distilled to isolate the ester because esters have lower boiling points than the ether. In distillation, the substance with the lower boiling point evaporates and reaches the water condenser. The cool temperature allows the vapor to change states from gas to liquid which forces the liquid to drip back down the into the Hickman head due to gravity. In this reaction, the (1, 3,-dimethylbutyl) acetate was isolated from an unknown ether by distilling into the Hickman head. An IR spect rum of the final product is conducted to determine the desired product by comparing the bond groups of the given values. If the IR peaks and bonds are the same as the given, then the purified product would be the ester. A percent yield will be calculated to assess the amount of ester produced. Procedure: First, obtain an empty round bottom flask and find the mass. Add about 1.5mL of 4-methyl-2-pentanol in the flask and reweigh. With the 3mL of glacial acetic acid added, add sulfuric acid with a boiling chip. Conduct reflux with the apparatus conducted in previous labs with a water condenser attached to cool the reaction. Heat the apparatus for 60 to 70 minutes. Cool the reaction mixture and while stirring, add 2-3 mL of 5% aqueous sodium bicarbonate until carbon dioxide formation ceases. Transfer mixture and shake hard. Remove the aqueous layer and repeat the separation technique two more times. Remove as much water from the organic layer by adding small amounts of sodium sulfate and let the reaction stand for 10-15 minutes. After a week, transfer the reaction with the ether and ester into a vial and conduct distillation. Conduct distillation for 15 minutes at around 180 to 200 oC. Obtain and mass the final product. Conduct IR of starting reactants and products. Clean up stations and calculate the percent yield. Results and calculations: Table 1: Table of masses during experiment Theoretical yield for (1,3-dimethylbutyl) acetate = 1.68g of Percent yield: x 100% x 100%= 34.6% IR: Figure 2: IR before distillation Figure 3: IR after distillation Table 2: Values of IR for ester (1,3-dimethylbutly) acetate after distillation Discussion and Conclusion: For this experiment, the ester (1, 3-dimethylbutyl) acetate was synthesized from acetic acid and 4-methyl-2-pentanol. However, this is not a one reaction pathway because of the tetrahedral intermediate prevalent in esterification. The addition of the acetic acid leads to a more reactive electrophile. This causes a tetrahedral intermediate in which there are two equivalent hydroxyl groups. Then one of the hydroxyl groups is eliminated, a process known as tautomerism. This then gives water and ester as the final products. The reaction was successful produced from reflux but problems arose during the second component of this experiment, distillation. The ester also had a very distinct fruity smell. This reaction is refluxed because heat acts as a catalyst for the reaction. In the reaction pathway, the temperature is increased, allowing more geometrical collisions with the products and requires lower activation energy. This can be seen as an example of the Maxwell-Boltzmann curve. This was done uniformly by using the aluminum block at around 110 oC. After reflux occurred, a distillation apparatus was used in order to purify the ester from the ether. The boiling chip was added in reflux and distillation in order to ensure that the reaction did not overheat and burn the reaction. Boiling chips are often made from carborundum (carbon and silicon) which are chemically inert and allows sharp edges for bubbles to form which will not overheat the system. The substances in the reaction are allowed to boil more calmly rather than rapid boiling causing splatter and ruining the experiment. The water condenser was used for both in order to cool down the reaction in order to prevent burning of the reaction and ensuring that the product in the vapor state turned back into liquid state. The reason why anhydrous sodium bicarbonate was added was to ensure that any leftover water was absorbed and the remaining layer contained only the organic compounds. This was done a total of three times to ensure that minimal water was left, but some of the product leaked when shaken. The purpose of distillation is to separate compounds based on their boiling points. The reaction mixture that contained ester and ether was to be distilled in order to obtain the ester in the Hickman head. However, after letting the reaction stand for a week, most of the ether evaporated and the mixture was mostly ester. This explains why during distillation, the mixture in the conical vial disappeared as most or all went into the Hickman head. This can be seen in Figures 2 and 3. The IR of before and after distillation have similar values, peaks, and the exact functional groups which indicates that the mixture contained only the ester. The IR spectroscopy of after distillation shows that there is a C=O bond around 1735.27 cm-1, and a sp3 C-H bond around 2959.19 cm-1 which indicates that the compound shown is indeed an ester and that the objective was met since ester do have C=O bonds around 1750 cm-1 and sp3 C-H bonds around 2900 cm-1 . Ideally, the distillation process should be us eful in isolating the pure product, by allowing the ester molecules to be in a gaseous phase. Equilibrium will be established and allows the molecules to form back into a liquid phase in the Hickman head, but in this experiment distillation was not necessary. This just caused more chances of losing the ester by not fully attaining all the liquid from the Hickman head or by evaporating. The results yielded a 34.6% yield which suggested that there were errors within the reaction. One major reason as to why the yield was low was because of the nature of the reaction itself. The ether and ester in the conical vial was left to stand for a week. Because the ether had a lower boiling point than ester, most or all of the ether evaporated due to high volatility at room temperature. In addition, the ester also has a high volatility but lower than the ether because of the structure and the strength of the intermolecular forces. The ester has two oxygen atoms whereas the ether has one oxygen resulting in lower van der Waal forces. The ether was created as a byproduct which affected the maximum amount of yield of ester produced. Therefore, not all the reaction occurred to form an ester because during that time there were compounds that hindered the maximum amount of yield formed by forming a pathway for the ether. This was from the sulfuric acid reaction mechanism to produce an ether. The sulfuric acid dissociates into a proton and a bisulfate ion which forms with the OH group of the alcohol. The alcoholââ¬â¢s oxygen is protonated which forms an oxonium ion. The ion decomposes to carbocation and water and the carbocation reacts with another alcohol group to form another oxonium ion. The ion loses a proton to stabilize and forms an ether. If a stronger alcohol, perhaps 1-hexanol was used, a higher yield would be attained because the stronger intermolecular forces allows the reaction to have lower volatility and the ester and ether formed would also evaporate less. Because there are weaker van der Waal forces in the (1, 3-dimethylbutyl) acetate because of the lower carbon chains, more of the product was evaporated and lost. In order to ensure that a higher yield is attained, the reflux and distillation process must be done back to back or a lot quicker before the ester and ether evaporates at room temperature. Also an alcohol with a longer carbon chain s hould be used as stronger intermolecular forces allow more ester to form. While transporting the organic layers and further extraction, some of the product was lost. Even though this source of error is minimal, there were some product lost along the way by transporting through vials which affected the yield of the final product. Reflux is an effective technique that allowed Fischer esterification to occur. Distillation is a very useful technique, but should not be relevant when one of the substances evaporates due to high volatility. For future experiments, the reaction must be done much quicker in order to ensure that the least amount of ether and ester evaporates and is lost throughout the process and more precise instruments can be used to extract the organic layer. IR should still be used to discern the identity of the product. Because of the nature of the reaction itself, a yield close to the theoretical is very difficult to attain, a realistic approach would be around 60% yield. Work Cited: MSDS of (1,3-dimethyl butyl) acetate. http://www.chemicalbook.com/ChemicalProductProperty_EN_CB8373308.htm (accessed November 7, 2014). MSDS of 4-methyl-2-pentanol. http://www.sciencelab.com/msds.php?msdsId=9926088 (accessed November 7, 2014). Padias, Anne.Making the Connections. Hayden McNeil, 2011.
Monday, January 20, 2020
AIDS :: HIV Diseases Health Medical Essays
AIDS Sub-Saharan Africa is the region of the world that is most affected by HIV/AIDS. An estimated 26.6 million people are living with HIV/AIDS and approximately 3.2 million new infections occurred in Sub-Saharan Africa in 2003. In just the past year the epidemic has claimed the lives of an estimated 2.3 million Africans. Ten million young people (aged 15-24) and almost 3 million children under 15 are living with HIV. An estimated eleven million children have been orphaned by AIDS in Sub-Saharan Africa. This is not just an African problem this is a world wide concern. It is estimated that over 50 million world wide have contracted the HIV/AIDS virus. (www.avert.org/aafrica.htm) Why during such an epidemic are drugs not reaching the people who need them? There are a few issues surrounding the distribution of these and other drugs including market size, patent laws, compulsory licensing, and price discrimination. Pharmaceuticals have played a key role in improving health world wide. Health trends in the 20th century have had significant improvement due to vaccines and other technological advances. It has been shown from 1962-1987 that a 74 percent decline in infant mortality rates can be attributed to technological advances. (Journal of Economic Perspectives) However, distribution in developing countries is still in dire need of improvement. A major reason for lack of access to pharmaceuticals in developing nations is the size of the market and the lack of revenue that can be obtained from consumers there. As shown in Table 1 from the Journal of Economic Perspectives the US holds almost 40 percent of the worldââ¬â¢s pharmaceutical market while Africa has only l percent. The market in Africa and other developing nations is significantly smaller, ââ¬Å"Drug developers often do not even bother to take out patents in small, poor countriesâ⬠(Journal of Economic Perspectives p70). Diseases in developing countries mainly infectious and parasitic diseases differ from the noncommunicable conditions found in more developed countries, the high cost of research and development and the low payback from consumers in developing countries deter pharmaceutical companies from investing time and energy into diseases that mainly affect developing nations. Developed nations spend an average of $4,000 per person per year on health while developing nations spend on average less than $20 per person. Such a large gap in health spending does not give pharmaceutical firms an incentive to provide research and development in these areas.
Sunday, January 12, 2020
Cult of Masculinity in “In the Country of Men”
In the book ââ¬Å"In the Country of Menâ⬠, Hisham Matar, the author discusses his childhood experience in the 1970's during the revolution in Libya. The time when men overpowered and completely dominated women. The title itself describes Libya as a country that belongs to men where women are used like tools. We see that Suleiman wants to become a man as soon as possible through the story but on the other hand, the story also talks about a female being Suleimanââ¬â¢s mother ââ¬â Najwa who thinks she lost her freedom when she was just 14 and had to get married. However, after all the development from the 1970ââ¬â¢s till today, the current generation considers both men and women equally powered. Right from the starting, it can be predicted that Suleiman wants to be a man. When baba goes on the so called ââ¬Å"business tripâ⬠, Suleiman is the only male in the house making him the man of the house. It is just the way how baba says it every time he leaves ââ¬â ââ¬Å"Take care of your mother, you are the man of the house nowâ⬠(61). Suleiman handles these responsibilities very well. He takes care of his mother as he knows very well that she is ill every time baba is not home and wants to take over a men's responsibility of taking care of his mother. He even talks about him willing to take responsibilities like his father and be just like him, a man. Later in the story, we also see the cult of masculinity urge through Suleiman when he and the other neighborhood kids were at Adnanââ¬â¢s house to look at him inserting an injection in himself due to his illness. ââ¬Å"I also prayed for a disease that would give me what Adnan hadâ⬠(126). Suleiman thinks that Adnanââ¬â¢s disease makes him seem older and more independent like a man. Thus Suleiman wants to have Adnanââ¬â¢s illness so that he too could be like a man. ââ¬Å"I couldnââ¬â¢t wait to be a manâ⬠(148). Suleimanââ¬â¢s words prove how he wants to become a man and does not want to fall into kidââ¬â¢s category. However, on the other side, there are still clues given throughout the story that prove how Suleiman has failed to be a man. For example, during the visit of the RCC (Revolutionary Committee Men) to Babaââ¬â¢s house to find Baba and any evidence against him. ââ¬Å"I was wet beneath my clothes and realized what I had done. The pee felt warm and cold and sticky to my skinâ⬠(64). When the RCC man had asked him about his father, Suleiman gets scared and pees himself not being able to control him. Even though he was the ââ¬Å"man of the houseâ⬠this incident proves him as a kid who cannot control himself. Another example was when Najwa tells Suleiman about how Faraj, who she belonged to, and all the other men out there had to puncture his wifeââ¬â¢s veil and bleed her to prove his wife as a virgin. ââ¬Å"I didnââ¬â¢t know what Mama meant, but feared that when the time came I might not have what it takes to ââ¬Ëpunctureââ¬â¢ a womenâ⬠(13). Suleiman fears he might not be able to do the duty that every man is to do to prove his wife a virgin. Even though there are some responsibilities of a man that Suleiman has fulfilled, he still doubts if he will be able to be a real man just like his father was. Najwa, Suleiman's mom, as she like to say, lost her freedom when she was just 14 years old. She had been forced to marry a completely strange man who was 9 years older than her even though she wanted to complete her education first. She being the girl was not even allowed to reject the marriage or even argue to defend herself. The High Council decided my fateâ⬠(144). When she says ââ¬Å"High Councilâ⬠it meant all the males in the house ââ¬â her father and all her brothers. Here we see that women had no choices but to obey what the males or so called ââ¬Å"High Councilâ⬠said. Also the only reason why the family to marry Najwa as quickly as possible is because one of her brother had seen her with another guy same age as her at the Italian Coffee shop and so they wanted to get rid of her before someone can spread rumors about them and ruin their reputation. In a family like Najwa's, members cared more about the family's reputation then ever caring about a woman. She remembered her grandmother say to her ââ¬Å"If a slave came to propose, a slave as black as this night, I would give you to himâ⬠(144). This definitely proven that girls/women did not have any right to speak up for themselves. They were just there to keep their men happy and follow their orders. After the ââ¬Å"Black dayâ⬠ââ¬â day she got forced to marry baba, her life has not changed very much. She is only there to keep baba happy since he is the man of the house. When baba is away she is ill. She starts drinking alcohol as a symptom of depression due to the freedom she has lost. And when baba returns, she dresses up good to please her man. ââ¬Å"During those nights, when Baba was home, Mama dragged her blanket behind her to the sofaâ⬠(85). She does not like to sleep in the bed with Bu Suleiman even though he is her husband. However if the man demands something then she could not reject him. She is basically like a slave of the man in the house. For example, the marital bed scene describes what she has to do for her man. ââ¬Å"I saw him on top of herâ⬠¦. she lay beneath him, unmoving, looking awayâ⬠(86). Also, the only role of women seen in the book is ââ¬Å"A women had to be young and strong enough to bear children and serve the man well into his old ageâ⬠(151). This definitely proves how women did not have the rights to express them self, were treated like slaves and their only role was to obey their man. Therefore, it could be concluded that the Cult of Masculinity has a huge impact on Suleiman and Mama. Males are always considered the higher authority in a family. It changes the way how Suleiman thinks and how Um Suleiman ââ¬â Najwa losses her rights to live her life the way she wants to. However, it still concerns me why women were treated so unequally compared to today. Today the women do not just have to take care of their family but can also work in any type of career they want to, while being treated equally as men.
Friday, January 3, 2020
The Health Organization Of The United States - 1290 Words
The World Health Organization (WHO) defines immunization as ââ¬Å"the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccineâ⬠(Immunization, 2014). The purpose of the vaccine is to use the bodyââ¬â¢s own immune system to protect the individual against a possible disease or infection later on. Immunizations have been proven to control and even eliminated life-threatening infectious diseases. It has been proven to be a very cost-effective investment, they are accessible to all populations including those who are at risk populations, and they do not require any major lifestyle changes. Immunizations have prevented between two million and three million deaths each yearâ⬠¦show more contentâ⬠¦Out of the Ten Essential Public Health Services it is clear that Healthy Peopleââ¬â¢s 2020 goal is using all ten of the services. They have been monitoring the health status of individuals in a community fo r health problems. They are diagnosing and investigating that health problems are a concern to the community. They are making it a point to inform, educate, and involve people about the current health issues. They are including the community and partnerships to help solve the health issues, and are developing policies and plans to support individual and community health efforts. Some places are enforcing policies and regulations to protect individualââ¬â¢s health and ensure safety. These policies are then linking the personal that is needed to assure the provision of health care. The public health and personal health care is competent, and they are evaluating the effectiveness, accessibility, and quality of personal and population-based health services. The research is continuing to look for new insights and ways to solve these health care issues (Hunting Gleason, 2012). Not only are all Ten of the Essential Public Health Services being used, but so are all three of the core functions which include; assessment, policy development, and assurance (Hunting Gleason, 2012). A study was performed in nine states from the
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