The Advantages And Disadvantages Of An Esters

In the Casey Anthony case Jeff Ashton who is a former state attorney in Orange county Florida, and also the first prosecutor in the United States to get a conviction based on DNA decided to use a new Forensic method in the Anthony case. The smell of death would be the allowed as evidence for the first time ever. In the trunk of Anthony’s car was a stained area on the carpet and an odor. Ashton stated that the smell was that of human decomposition. That piece of carpet was removed, sealed and sent to Dr. Vass, a forensic anthropologist at Oak Ridge National Laboratory. Dr. Voss has been studying human decomposition at the University of Tennessee’s “body farm”.

In this experiment, an unknown alcohol underwent a Fischer Esterification reaction by reacting it with acetic acid as well as sulfuric acid catalyst. The unknown product material was purified through distillation and characterized by analyzing an IR spectrum and determining the density of the product. In addition, the boiling point test was performed to test for an ester. Lastly, the starting material, an unknown alcohol, was determined after finding out the product and examining the IR spectrum for the reactant.

At room temperature (25°C), esterification reactions are relatively slow, therefore requiring the rate of the chemical reaction to be increased for the products to be formed efficiently. This is implemented, by using a catalyst, such as concentrated sulphuric acid (H2SO4 (aq)), as well as by heating the mixture: using a heating mantle. As a result, the energy of the reactants can be greater than the activation energy, increasing the rate of reaction. Hence, as the reactants are relatively volatile, so reflux apparatus such as a pear-shaped flask and a Liebig condenser were used, to minimise the amount of reactants lost, as well as allow the reaction to take place at the highest temperature possible. In addition, boiling chips were added prior to reflux, to prevent bumping and a decrease a loss of volatile reactants, during the reflux

Ethyl ethanoate: Ethyl ethanoate is an ester. Esters are group of organic compounds which have a functional group of –COO-. Esters are liquids that become vapours quickly so they are present in perfumes.

We took two versions of the same foods, one with additives and preservatives and one without, and fed them to participants. The foods are as follows: Canned and preserved carrots and carrots that were boiled in salted water at home, chemically preserved bacon and naturally preserved (salt) bacon, coke sweetened with high fructose corn syrup and coke sweetened with cane sugar, and mountain dew sweetened with high fructose corn syrup and Mountain Dew sweetened with sugar, and made from scratch vanilla cupcakes and vanilla cupcakes made from a boxed cake mix. We ended up having store-bought vanilla cupcakes with poppy seeds for the first half of our experiment and vanilla cupcakes made from boxed cake mix for the second half because we did not have access to boxed cake mix at first and then re ran out of vanilla cupcakes with poppy seeds, so the box-made cupcakes were introduced. They were very similar in flavor and the change made no impact on our experiment. The participants were fed the food, one version and then the other for all the categories and then asked to identify which foods they thought had additives and preservatives and then asked to justify their answer. This was to ensure that they were not simply guessing the

The purpose of this lab was to synthesize the ester isopentyl acetate via an acid catalyzed esterification (Fischer Esterification) of acetic acid with isopentyl alcohol. Emil Fischer and Arthur Speier were the pioneers of this reaction referred to as Fischer Esterification. The reaction is characterized by the combining of an alcohol and an acid (with an acid catalyst) to yield and ester plus water. In order to accomplish the reaction, the reactants were

The purpose of this experiment is to prepare isopentyl acetate by direct esterification of acetic acid with isopentyl alcohol. After refluxing there is an isolation procedure where excess acetic acid and remaining isopentyl alcohol are easily removed by extraction with sodium bicarbonate and water. The ester is then purified by simple distillation and the IR is then obtained.

In this experiment, a Fischer Esterification reaction was performed with two unknown compounds. The unknown compounds, Acid 2 and Alcohol D, were identified by using the knowledge of the reaction that took place, and the identity of the product that was synthesized. The identification of the product resulted from analysis of IR and NMR spectra.

Purpose: The purpose of the experiment was to perform the acid-catalyzed Fischer Esterification of acetic acid and isopentyl alcohol to form isopentyl acetate, or banana oil, which is used in flavor industries. The equilibrium of the reaction was changed by adding an excess amount of acetic acid. The reaction was refluxed and product was purified by extraction and distillation. Isopentyl acetate was analyzed by infrared spectroscopy and 1H NMR spectroscopy.

Next, we looked at the olfactory responses of the remaining six odorants from the panel of seven that were mentioned above. As mentioned in the previous paragraph, starved and non-starved larvae were subjected to the two-choice assay after 2 hours of the starvation protocol. Data collected for all seven different odorants are shown in Figure 2. Of all the seven odorants tested, only three odorants showed significant changes in response indices upon starvation. Acetal (shown in Figure 1), 4, 5-dimethylthiazole, and pentyl acetate were the three odorants that showed higher RI values for starved state larvae when compared to non-starved larvae. In other words, for these three odorants starved larvae had higher attractiveness towards odorants compared to non-starved larvae. This supported our hypothesis that individual ORNs might be differentially modulated by the animal’s starved state.

There are various factors that can affect the sensitivity of our nose towards the odorants. Human, in fact, has an extraordinary superb sense of smell. We can sense the smell of sweat when we are in fear. We can detect and identify an odorant even at an extremely low concentration. We can also improve our sense of smell by practicing. (Sela & Sobel, 2010)

From Figure 1.2.1., there are 6 odourant samples (vinegar, black pepper, ginger, chocolate flavour, olive oil and bay leaf) have higher frequency of usage than accuracy of identification, while 4 samples (vanilla extract, cherry flavour, turmeric, mint) are the opposite.

Semiochemicals are organic molecules that transmit chemical messages within the same or different species of animals and plants. There are multiple distinctions within semiochemicals like pheromones, kairomones and allomones (Zumdahl, 1989). Pheromones are chemicals that have an effect on the receptors within similar species of the producer, and they tend to be highly volatile compounds (ibid). There are different types of pheromones according to the response they stimulate on the receiving party, as shown in figure 1. Volatile pheromones are represented as either sex or defensive pheromones and they usually produce a specific odor.

One of the major elements of human attraction is pheromones. Pheromones are biochemical molecules that can take many different forms, such as skunk spray, or pheromones in bees that direct them to flowers, or even sex pheromones. According to Psychology Today, The evaluative sniffing that mammals engage in during courtship were clues that scent is the chemical equivalent

* Fruits: Fresh fruits such as apples, strawberries, cherries unfortunately do not yield the expected odors when extracted; if such fragrance notes are found in a perfume, they are synthetic. Notable exceptions include litsea cubeba, vanilla, and juniper berry. The most commonly used fruits yield their aromatics from the rind; they include citrus such as oranges, lemons, and limes. Although grapefruit rind is still used for aromatics, more and more commercially used grapefruit aromatics are artificially synthesized since the natural aromatic contains sulfur and its degradation product is quite unpleasant in smell.