Esters Hydrolysis Rates

The purpose of this lab is to examine the composition of three components of gas products of elimination reaction under acidic condition by conducting the dehydration of primary and secondary alcohol, and under basic condition by conducting the base-induced dehydrobromination of 1-bromobutane and 2-bromobutane. Then gas chromatography is used to analyze the composition of the product mixtures.

The three things that can cause the enzyme to denature is a large change in pH level, High Temperature, and substrate concentration. According to our knowledge, we know that a large change in pH will cause instability in the protein structure thus resulting in denaturation of the enzyme. From the data, we can see that pH 3 (total:6.3) and 10 (total:6.2) were the slowest because pH 3 is probably the highest acid and pH 10 is the highest base. The highest acid or base pH represents a large change which would cause the enzyme to denature. The fastest pH was 6 (total:34.5), and it seems that there wasn’t a large change which resulted in a stable structure. The temperature in our experiment was not very high which didn’t result in denaturation of peroxidase. The temperature seemed to be a constant that didn’t affect the experiment. If the temperature was higher in pH 3 and low in pH 10, then it would cause pH 3 to denature even more which would make the pH 3 total about 4.0. Substrate concentration basically means the amount used for the substrate. The substrate in our experiment was 0.1% hydrogen peroxide. The 0.1% is the concentration amount. Just like temperature and pH, substrate concentration can speed the reaction only up to a certain limit. When we mixed pH 3 enzyme tube with substrate tube, we used 0.3 mL of hydrogen peroxide, but if we were to increase the amount, then the experiment would have been faster. Our

Enzymes are needed for survival in any living system and they control cellular reactions. Enzymes speed up chemical reactions by lowering the energy needed for molecules to begin reacting with each other. They do this by forming an enzyme-substrate complex that reduces energy that is required for a specific reaction to occur. Enzymes determine their functions by their shape and structure. Enzymes are made of amino acids, it 's made of anywhere from a hundred to a million amino acids, each they are bonded to other chemical bonds. The enzymeʼs have an active site that allows only certain substances to bind, they do this by having an enzyme and substrate that fit together perfectly. If the enzyme shape is changed then the binding

LABORATORY REPORT Activity: Enzyme Activity Name: Natalie Banc Instructor: Elizabeth Kraske Date: 09.22.2016 Predictions 1. Sucrase will have the greatest activity at pH 6 2. Sucrase will have the greatest activity at 50 °C (122 °F) 3. Sucrase activity increases with increasing sucrose concentration Materials and Methods Effect of pH on Enzyme Activity 1. Dependent Variable amount of product (glucose and fructose) produced 2. Independent Variable pH 3. Controlled Variables temperature, amount of substrate (sucrose) present, sucrase + sucrose incubation time Effect of Temperature on Enzyme Activity 1. Dependent Variable amount of product (glucose and fructose) produced 2. Independent Variable temperature 3. Controlled Variables pH, amount of

In this lab, the oxidation of a secondary alcohol was performed and analyzed. An environmentally friendly reagent, sodium hypochlorite, was used to oxidize the alcohol, and an IR spectrum was obtained in order to identify the starting compound and final product. The starting compound could have been one of four alcohols, cyclopentanol, cyclohexanol, 3-heptanol, or 2-heptanol. Since these were the only four initial compounds, the ketone obtained at the end of the experiment could only be one of four products, cyclopentanone, cyclohexanone, 3-heptanone, or 2-heptanone. In order to retrieve one of these ketones, first 1.75g of unknown D was obtained. 1mL of Acetic acid was then added to Unknown D and the solution was stirred. Next, 15mL of sodium

4. Describe what is measured as an indicator of sucrase activity and why this is an indicator of sucrase activity.

To catalyze a reaction, an enzyme will grab on (bind) to one or more reactant molecules. In this experiment we examined how increasing the volume of the extract added to the reaction would affect the rate of the reaction. The enzyme used was horseradish peroxidase which helps catalyze hydrogen peroxide. Using different pH levels, the absorbance rate of the reaction was measured to see at which condition the enzyme worked best. The rates of absorption were calculated using a spectrophotometer in 20 second intervals up to 120 seconds. It was hypothesized that the optimal pH for the enzyme was pH 7 while the 1.0 ml peroxidase would have the best reaction rate. At the end of the experiment the results prove the hypothesis to be incorrect.

Introduction: In this experiment, the identity and absolute configuration of an unknown chiral secondary alcohol will be determined using NMR and CEC. By using the given NMR data, the identity of the alcohol an be determined. In order to identify the stereochemistry of the alcohol, it will have to undergo an esterification reaction in which propionic anhydride, two enantiomers of HBTM(each used in different reactions), and triethylamine are used. Thin layer chromatography will be run at a specified time in the reaction, and the results will be examined both quantitatively(via ImageJ) and qualitatively to which reaction reacted more quickly. With this information, the stereochemistry of the alcohol can be deduced.

In this laboratory, methanol is reacted with a tertiary alkyl chloride to make ether. The triphenylmethyl is isolated from the triphenylmethyl chloride. Methanol is then added and the class does the recrystallization . The methanol acts as a solvent for the reaction as a nucleophile. Because it is a tertiary benzylic halide, the reaction is considered an SN1 type. To test the purity, the class then uses a TLC.  When one places,” a spot of the substance on the absorbent surface of the TLC plate, the solvent (or solvents) run up through the absorbent,” (Zubrick223). The initial mass of the reactant, triphenylmethyl chloride was 2.006 grams. The experiment yield is 1.589g, which is a 80.3% yield. The triphenylmethyl methyl ether is almost pure with only a 0.05 difference in Rf values.

The ester synthesis of isoamyl acetate for this lab was carried out through nucleophilic acyl substitution. The purpose of this lab was to demonstrate the procedure for the synthesis of an ester from a carboxylic acid and alcohol using the techniques of refluxing. An ester is a very important functional group because it is widely distributed in nature. Additionally, esters can be synthesized with different methods such as direct reaction between carboxylic acid and alcohol in the presence of a strong acid catalyst, this is called Fischer Esterification. Furthermore, the by-product of the reaction is water, which is produced as a result of a condensation reaction. Most importantly, this reaction is reversible, therefore, an excess of acetic acid is added to shift the equilibrium to favor the ester product. Also, to acid is removed from the product mixture for the ester to separate from the water by neutralizing the acid with a base. Overall, banana oil will be synthesized from acetic acid and isopentyl alcohol.

In this experiment, the reaction kinetics of the hydrolysis of t-butyl chloride, (CH3)3CCl, was studied. The experiment was to determine the rate constant of the reaction, as well as the effects of solvent composition on the rate of reaction. A 50/50 V/V isopropanol/water solvent mixture was prepared and 1cm3 of (CH3)3CCl was added. At specific instances, aliquots of the reaction mixture were withdrawn and quenched with acetone. In addition, phenolphthalein was added as an indicator. The aliquots were titrated against sodium hydroxide (NaOH) solution until end point was reached, after which volume of NaOH consumed was recorded. The value of the rate constant, k, obtained was 0.0002 s-1. The experiment was then repeated with 40/60 V/V isopropanol/water mixture and a larger value of k = 0.0007 s-1 was obtained. We concluded that the rate of hydrolysis of (CH3)3CCl is directly proportional to water content in the solvent mixture.

In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes. After reflux, we removed the reaction mixture from the apparatus and cooled it for several minutes. We transferred the mixture to the beaker that contained water (30 mL). We cooled the mixture to room temperature and added sodium carbonate to neutralize the mixture. We added sodium carbonate until the pH of the mixture was 8. After neutralize, we collected benzocaine by vacuum filtration. We used a Buchner funnel to collect benzocaine. We used three 10 ml of water to wash the product. After the product was dry, we weighed, calculate the percent yield and determined the melting point of the product.

As per schedule1, 0.212g of aspirin was added to 50 ml boiling water to form salicylic acid in a 100 ml flask, of which 1 ml was then pipetted to a 50 ml volumetric flask at the 5th min. Following an ice bath, the solution was mixed

There are several factors which affect the rate of reaction: catalyst, reactant concentration, and temperature.1,2

The goal of the experiment is to examine how the rate of reaction between Hydrochloric acid and Sodium thiosulphate is affected by altering the concentrations. The concentration of Sodium thiosulfate will be altered by adding deionised water and decreasing the amount of Sodium thiosulphate. Once the Sodium thiosulphate has been tested several times. The effect of concentration on the rate of reaction can be examined in this experiment.