Introduction:
Esters are organic compounds which are naturally found in many flowers and fruits, esters are also created synthetically by a reaction between a carboxylic acid and an alcohol leading the formation of an ester, and water called esterification. The reaction uses an acid catalyst to speed up the process ex. Sulfuric acid (p.51 Nelson, 2010).
Esterification
The letters R in the reaction represent alkyl groups which are made up of carbon atom(s). An esters structure as shown contains a carbon atom double bonded to an oxygen atom, single bonded to an oxygen atom which is bonded to an alkyl group, and single bonded to another alkyl group as shown in the image (p.49 Nelson, 2010). The first portion of an esters name is derived
Condensation reaction is a chemical reaction that joins two reactants to form a larger molecule with the loss of a small molecule, usually water. 1 This reaction is used as a basis for many important process in the plastic/food industry. The most common being the formation of ester, also known as esterification. When a carboxylic acid is reacted with alcohol in the presence of a dehydrating agent, ester and water molecule are formed as products:
In this experiment, the Fischer Esterification of an unknown acid and an unknown alcohol was used to prepare an unknown ester. Sulfuric acid was used as a catalyst in the reaction which then was put under reflux. After cooling, the pH of the solution was raised to approximately 8 using sodium carbonate. Diethyl ether was added, then the aqueous layer was removed and the organic layer was washed with sodium chloride. The aqueous layer was removed again and sodium sulfate was added. The unknown product was then identified using gas chromatography (GC) to obtain the retention time.
Grignard reagents are reactive enough to also attach esters; however, two equivalents of the Grignard reagent are usually added because less then two equivalents leave a large quantity of unreactive ester. This reaction forms a tertiary alcohol.
To prepare and purify an ester: 1-pentyl ethanoate, using pent-1-ol and ethanoic acid. An annotated reaction showing this reaction is shown below:
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.
Enzyme catalysis is the increase in the rate of a chemical reaction by the active site of a protein. A catalyst is a substance that can help the reactants in a chemical reaction react with each other faster. The catalyst for this experiment is yeast. In this lab, the chemical combination of hydrogen peroxide and yeast are used to form a reaction of creating oxygen. The active sites of the yeast combines with the hydrogen peroxide and causes oxygen to form at various levels. Yeast is a one-celled organism belonging to the group of organisms called fungi. Yeast is sometimes used in genetic engineering to produce large quantities of enzymes that can be used for medical purposes as healing wounds and reducing inflammation (How Stuff
An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of 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 goal of this experiment was to synthesize aspirin. In this experiment aspirin, also known as acetylsalicylic acid, was synthesized from salicylic acid and acetic anhydride. In the reaction the hydroxyl group on the benzene ring in salicylic acid reacted with acetic anhydride to form an ester functional group. This method of forming acetylsalicylic acid is an esterification reaction. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in the solution as well as some sulfuric acid, aspirin, and acetic acid. Crystallization, which uses the principle of
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.
In this laboratory the objectives were to understand the effects that temperature has on a reaction, be able to calculate the reaction’s rate constant, and to calculate the activations energy from the recorded rate constant. Activation energy is the minimal amount of energy that is necessary to result in a chemical reaction. With an insufficient amount of energy, a reaction won’t occur, too much and it will react just fine. A great example of this can be lighting a match. The friction created when striking the tip covered in Potassium Chlorate against the match pad is enough energy for it to ignite.
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.
Abstract Enzymes are proteins known as catalysts—substances that increase the rate of chemical reactions. Within this experiment, an enzyme called catalase was measured in two experiments and observed to determine the time required to make 10 mL of oxygen through a catalyzed breakdown of hydrogen peroxide. For experiment 1, the effect of varying substrate concentration on enzyme kinetics, we tested the hypothesis that the higher the substrate concentration, the slower the reaction will be. In experiment 2, the effect of temperature on enzyme kinetics, we tested the hypothesis that the room temperature enzyme and the warm enzyme would have the fastest reaction rate (Hester, Degenhart 2015).
In this part of experiment, alcohol(2ml) and CH3COOH(1ml) will react to produce an ester, the ester's odor can then be compared with that of the ester bank to determine the identity of the ester. This is done by mixing the reagents in the solution with a glass stirring rod and then to further dissolve the solution, it