For this experiment, a Fischer esterification reaction was observed. A Fischer esterification is a reaction that converts a carboxylic acid into an ester. Within the reaction, the hydroxyl portion, -OH, of the carboxylic acid is replaced by an -OR group. The byproduct is water which is also a nucleophile. Therefore, water can be added back into the compound and undergo hydrolysis on the newly formed ester which produces the starting carboxylic acid. To make sure the reversibility did not occur, the reaction mixture was heated to force the water to evaporate and therefore be removed from the overall reaction. The main idea of Fischer esterification is to form a carboxylic acid and make it a better electrophile under acidic conditions. This is …show more content…
Fischer was a well-known chemist who won the second Nobel Prize in chemistry. He is also notable for Fischer projections. His method was to run the reaction under acidic conditions. To do this, the oxygen was protonated to make it a good nucleophile. The carbon is then strong enough to react with the alcohol. This can then go on to make a good leaving group, water, which comes off. In the last step, a proton is removed. His method was ran under acidic conditions to make the electrophile a better electrophilic carbon. This reaction works very well. An ester is derived from a carboxylic acid. The oxygen of the alcohol is the nucleophile and the carbonyl carbon of the carboxylic acid is the electrophile. The oxygen makes the carbon more electrophilic causing the alcohol to attack since the oxygen does not want to be positively charged. The solvent used was concentrated sulfuric acid which promoted the addition of the weak nucleophile, the alcohol of the carboxylic acid, to be replaced with an -OR group. A proton is gained back from the hydroxyl group of the carboxylic acid after being lost. After this, a proton shift occurs that gives up the leaving group of water which is the byproduct since it …show more content…
The first is the proton source. A certain one must be used. It is typically done with sulfuric acid, but hydrochloric acid can also be used. A strong base is not used so a strong acid is utilized. To make enough product, a strong acid is used to push the reactants into products to produce enough product. Phosphoric acid is an exception in that it can also be used but a strong acid is preferred to make the reaction go to completion. The second problem deals with equilibrium which is the most important. If the reaction was performed with an alcohol, methanol or ethanol, and a carboxylic acid, acetic acid, the equilibrium constant, Keq, would be 4. The Keq is the concentration of products divided by the concentration of reactants. In this case it would be ([ester][water])/([alcohol][acid]). The two products are ester and water and the two reactants are alcohol and carboxylic acid. The concentration of alcohol and ester are unknown, but they are equal to one another. The reactants are essentially the same and they should be in a 1:1 ratio to keep the concentrations equal to one another. In this reaction, a lot of waste is unwanted which this would produce excess waste. By producing a lot of waste, reactant, it increases the cost of waste disposal, so this method is not used. The main goal is to get the reactants to be equal to one another, so the reactants are (1-x). The
Table 6 shows the results of the biochemical tests. The isolate can obtain its energy by means of aerobic respiration but not fermentation. In the Oxidation-Fermentation test, a yellow color change was produced only under both aerobic conditions, indicating that the EI can oxidize glucose to produce acidic products. In addition to glucose, the EI can also utilize lactose and sucrose, and this deduction is based on the fact that the color of the test medium broth changed to yellow in all three Phenol Red Broth tests. These results are further supported by the results of the Triple Sugar Iron Agar test. Although the EI does perform fermentation of these three carbohydrates, it appears that this bacterium cannot perform mixed acid fermentation nor 2,3-butanediol fermentation due to the lack of color change in Methyl Red and Vogues-Proskauer
The experimental Fischer esterification of 8.92g of acetic acid with 5.0g of isopentyl alcohol using concentrated sulfuric acid as a catalyst yielded 4.83g (65.3% yield) of isopentyl acetate. The product being isopentyl acetate was confirmed when the boiling point during distillation had similar characteristics to that of the literature boiling points2. Physical characteristics like color and smell also concluded a match of our product with what was intended. 1H-NMR spectroscopy analysis supported this claim due to the fact that the integration values and chemical shifts were comparable to isopentyl acetate. Lastly, infrared spectroscopy (IR) showed similar key characteristics of our product’s wavelengths to that of pure isopentyl acetate5.
Hydration of alkenes is characterized by the addition of water and an acid-catalyst to a carbon-carbon bond leading to an alcohol. Dehydration is exactly the opposite in which dehydration of an alcohol requires water to be removed from the reactant. Equilibrium is established between the two processes when the rate of the forward reaction equals the rate of the reverse reaction. The alkene that is used in this experiment is norbornene. Through hydration of norbornene, an alcohol group should be present on the final product yielded what is known as exo-norborneol. Percent yield is a numerical indication of how much of the reactant was actually reacted to yield product. The equation for percent yield is shown below:
The weight of the final product was 0.979 grams. A nucleophile is an atom or molecule that wants to donate a pair of electrons. An electrophile is an atom or molecule that wants to accept a pair of electrons. In this reaction, the carboxylic acid (m-Toluic acid), is converted into an acyl chlorosulfite intermediate. The chlorosulfite intermediate reacts with a HCL. This yields an acid chloride (m-Toluyl chloride). Then diethylamine reacts with the acid chloride and this yields N,N-Diethyl-m-Toluamide.
need is water and an ester and we will end up with an organic acid produced as
The purpose of the experiment is to study the rate of reaction through varying of concentrations of a catalyst or temperatures with a constant pH, and through the data obtained the rate law, constants, and activation energies can be experimentally determined. The rate law determines how the speed of a reaction occurs thus allowing the study of the overall mechanism formation in reactions. In the general form of the rate law it is A + B C or r=k[A]x[B]y. The rate of reaction can be affected by the concentration such as A and B in the previous equation, order of reactions, and the rate constant with each species in an overall chemical reaction. As a result, the rate law must be determined experimentally. In general, in a multi-step reac...
And that is almost assuredly his goal from the very beginning, as it must be for any published author in the chemistry community. Works Cited Church, L. B. & Co., L. B. The Chemistry of Winemaking. A Unique Lecture Demonstration.
The three butene products have been verified to elute in the following order: 1-butene, trans-2-butene, and cis-2-butene. Theory: The dehydration of 2-butanol, a secondary alcohol, progresses readily in the presence of a strong acid like concentrated sulfuric acid (H2SO4). The reaction is completed via the E1 mechanism. Initially, the hydroxyl group is a poor leaving group, but that is remedied by its protonation by the acid catalyst (H2SO4) converting it to a better leaving group, H2O. The loss of this water molecule results in a secondary carbocation intermediate that continues to form an alkene in an E1 elimination.
The percentage yield gained was 70% from the Fischer Esterification reaction, which evaluates to be a good production of yield produced as the reaction is known to be reversible where conditions such as the concentration of the reactants, pressure and temperature could affect the extent of the reaction from performing. These white crystalline crystals were tested for impurity by conducting a melting point analysis and taking spectrospic data such as the IR spectra, HNMR and CNMR to confirm the identification of the product. These spectrospic methods and melting point analysis confirmed the white crystalline crystals were benzocaine.
Chemical kinetics is a branch of chemistry that involves reaction rates and the steps that follow in. It tells you how fast a reaction can happen and the steps it takes to make complete the reaction (2). An application of chemical kinetics in everyday life is the mechanics of popcorn. The rate it pops depends on how much water is in a kernel. The more water it has the quicker the steam heats up and causes a reaction- the popping of the kernel (3). Catalysts, temperature, and concentration can cause variations in kinetics (4).
In our Biology Lab we did a laboratory experiment on fermentation, alcohol fermentation to be exact. Alcohol fermentation is a type of fermentation that produces the alcohol ethanol and CO2. In the experiment we estimated the rate of alcohol fermentation by measuring the rate of CO2 production. Both glycolysis and fermentation consist of a series of chemical reactions, each of which is catalyzed by a specific enzyme. Two of the tables substituted some of the solution glucose for two different types of solutions. They are as followed, Table #5 substituted glucose for sucrose and Table #6 substituted the glucose for pH4. The equation for alcohol fermentation consists of 6 Carbons 12 Hydrogens 6 Oxygen to produce 2 pyruvates plus 2 ATP then finally the final reaction will be 2 CO2 plus Ethanol. In the class our controlled numbers were at Table #1; their table had 15 mL Glucose, 10 mL RO water, and 10 mL of yeast which then they placed in an incubator at 37 degrees Celsius. We each then measured our own table’s fermentation flasks every 15 mins for an hour to compare to Table #1’s controlled numbers. At
Introduction Most mammals are initially born with the ability to break down the polysaccharide, lactose into smaller monosaccharides but at an early age, usually as the child starts to rely less on their mother for direct nurturance, this ability ceases. This inability to break down lactose is known as lactase non-persistence. Lactase Non-persistence is the wild type in the population surprisingly even though a vast majority of the population is lactase non persistent. Individuals with the ability to digest the lactose found in milk are considered lactase persistent or lactose tolerant.
The aim of this experiment was to investigate the affect of the use of a catalyst and temperature on the rate of reaction while keeping all the other factors that affect the reaction rate constant.
electrophile (electron pair acceptor) with an attached leaving group. This experiment was a Williamson ether synthesis usually SN2, with an alkoxide and an alkyl halide. Conditions are favored with a strong nucleophile, good leaving group, and a polar aprotic solvent.
Introduction Enzymes are classified as being a class of proteins. In other words, the basic structures of enzymes are formed by chains of amino acids. Enzymes, as all other kind of structures, can breakdown in some circumstances. The pH, for instance, is one of the factors that affect the enzymes. Changes in pH not only affect the shape of an enzyme, but it also charges properties of substrate, which will eventually block the bind of the substrate with the active site and prevent it to undergo catalysis (Boumis 2012).