Silica Beadss Experiment

On a large scale ethanol and ethanoic acid is added to get the product ethyl ethanoate and water.

Based on the 1H NMR spectrum that was collected, a few things can be determined. Based on deshielding and electronegativity, the peak that occurs around 4.7ppm is associated with the O-ethylsaccharin product and the peak at 3.8 ppm is associated with the N-ethylsaccharin product. Based on the height ration, the N-ethylsaccharin product is the more prevalent result.

Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.

This experiment utilized the dehydration process of 2-methylcyclohexanol to give a mixture of 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane. According to Zaitsef’s rule, 1-methylcyclohexene is the major product because it is the most highly substituted product, making it the most stable. 25 mL of 2-methylcyclohexanol was placed into a 100mL round-bottom flask along with 10mL of 9 M sulfuric acid and swirled to mix the contents. [1] H2SO4 is used for the E2 reaction of dehydrating a primary alcohol. The –OH group in 2-methylcyclohexanol donated two electrons to a proton from H2SO4, which forms an alkyloxonium ion. [5] The HSO4- nucleophile attacks an adjacent hydrogen and the alkyloxonium ion leaves, forming a double bond. [5]

The objective of this experiment is to prepare and identify several types of esters by the process of dehydration synthesis using an alcohol with an acid.

The reaction took place in a conical vial and .2mL of each of the reactant samples were added to it along with some 95% ethanol. Two drops of NaOH were added shortly after and stirred at room temperature for fifteen minutes. The vial was cooled in and ice bath and crystallized. Vacuum filtration was performed to filter the crude product. The crude product was recrystallized using methanol and filtered again. We made one change to the procedure and instead of using .7mL of ethanol we

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

In basic chemistry, ester can be formed through alcohol and carboxylic acid reactions. Ester have functional group of (-COO-) that will attach on the reaction. In the review of Faraj et al., 2010, the fischer esterification is an equilibrium response, while other esterification courses does not include equilibrium. To move the equilibrium to support the generation of esters, it is standard to utilize an abundance of one of the reactants, either the liquor or the corrosive. In the present responses, an abundance of the phenol (Aldrich, 98% virtue), dodecylamine (Merck, 97% virtue), 1-octadecanol (Merck, 97% immaculateness), and polyethylene glycol (Fluka with 98% virtue and a normal sub-atomic mass of 14000) have been utilized, on the grounds that it is less expensive and less demanding to evacuate than the carbon nanotubes. Another approach to drive a response toward its items is to expel one of the items as it structures.

Jack Kelly Experiment 2: Esterification Organic Chemistry II Lab CH224-53 Dr. Kwan Introduction Experiment 2 involves an esterification reaction, shown in figure 1. Each student was given an unknown, which consisted of an acid and alcohol mixed together. The unknowns all had low molecular weights, causing them to have a strong odor. For this reason, the unknowns were only supposed to be opened under the hood, so that no strong scents were sitting in the lab. Each unknown was heated and mixed with concentrated sulfuric acid, producing an ester and bi-product of water, which can be seen in figure 1 as well.

As the reagents were heated, a strong banana odor was present, and was especially strong during extraction. The condensed product was then cooled to lower the temperature, which allows for the C-O and O-H bonds in the products to form. Sodium bicarbonate was added to the acetic acid to form sodium acetate and carbonic acid, since the acetic acid was highly water soluble. The carbonic acid was then spontaneously broken into water and carbon dioxide molecules. The sodium acetate was extracted after each time the sodium bicarbonate was added for a total of four times.

This data would indicate that the ester was converted into the targeted alcohol. In order to confirm this assumption H-NMR was employed. Since both compounds contain a benzene ring and at least one methyl group, the peaks around the 7ppm and 1.5ppm regions would not be enough to distinguish between the two compounds (6, 7). Instead the signals at 5.9ppm and 4.8ppm were looked at to distinguish between the two compounds. Since esters contain multiple electronegative oxygens the proton attached to the carbon adjacent to the ester experiences a greater magnetic field and thus a more downfield signal at 5.9ppm (6, 13), whereas the single oxygen of the alcohol induces a slightly weaker upfield signal at 4.8ppm (7, 13). Additionally, for the NMR spectra with the signal at 4.8ppm, there was a single short peak at 2.7ppm that is a unique signature to the presence of an alcohol (13). Lastly TLC chromatography was used while monitoring the progress of the lipase reaction. The ester is slightly less polar than the alcohol because the ester lacks the ability to be a hydrogen bond donor making it more nonpolar by comparison. As a result while monitoring TLC the ester had traveled further up the polar stationary phase, silica plate, while the alcohol traveled slower the plate (11). This same logic was applied to explain why it took the alcohol longer to elute from column

As each stage of the experiment was completed the current ‘compound’ was spotted on the plate, establishing the following results: 2-naphthol had an Rf of (3.1/4.5=0.69), the post-microwave/pre-work up had two spots with Rfs of (2.9/4.5=0.64) and (3.4/4.5=0.76), and the post-extraction had one spot with an Rf of (3.4/4.5=0.76). Since the product we’re looking for is less polar, we expect it to have a higher Rf value than the starting value; the data collected supports this, as 0.76 > 0.69. Therefore the TLC plate supports the formation of the correct product. Additionally, the third lane of the plate was centered very precisely at an Rf value of 0.76 and did not have an additional spot like the second lane did. Thus the post-extraction product contains only one pure

Two catalyst reactants are used in the experiment, thiosulfate and starch, to dictate the time of reactions.

The purpose of this lab experiment is to study a simple esterification reaction, producing acetylsalicylic acid (aspirin), thus becoming familiar with synthetic chemistry tools and techniques.

with the reaction of alcohol and acyl chloride, with the ester there is HCl, so in such esterification