The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst. It forms a complex with HBr and extracts it from the aqueous phase into the organic phase where the alkene is. This dehydrates the acid, making it more reactive so that the addition reaction is possible. Rapid stirring is required in order to maximize the surface area …show more content…
This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone. In this test, primary halides precipitate the fastest while secondary halides need to be heated in order for a reaction to occur. Comparison of the rates of precipitation of the obtained product to standard 1° and 2° bromide solutions will show whether the product is a primary or secondary
After adding the acetic acid and hydrobromic acid to the solution, and heating and recrystallizing the solution, the product triphenylmethyl bromide was created and had a mass of 0.103 g. The theoretical yield was calculated by determining the limiting reagent in the reaction. The triphenylmethanol was the limiting reagent in the reaction. The total amount of mass from the triphenylmethanol was converted to moles by using the molar mass of the triphenylmethanol. The amount of moles was then converted into grams to determine the theoretical yield, 0.125 g. The percent yield was then calculated by dividing the actual yield by the theoretical yield and multiplying the result by 100%. The percent yield was 82.4%.
In this lab experiment, I experimented with 2 different amount of borax (1g and 5g) to see if the amount of borax affects the bounce height of the ball. The ball is made up of polyvinyl acetate (school glue), borax and water. In the experiment the independent variable is borax and the dependent variable is the bounce height. I found out that borax has sort of a protective layer that creates the bounciness. Therefore, I hypothesized that the more borax that is used, it would be more bouncy, because there is more of a protective layer to it.
Chem 51LB Report Ngoc Tran - Student ID # 72048507 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. Gas chromatography (mobile phase) is used to analyze the composition of three components of the gas products. A syringe needle with gas product is injected into the machine, and the component is eluted and the composition is related to the column or the peaks.
This experiment was started to measure the height equivalent of a HETP column to calculate twenty theoretical plates. The company need this information to separate the cyclohexane from the toluene. The separation was accomplished by the use of fractional distillation and gas chromatography. The process yielded one plate for the17.6cm column meaning, that the porcelain beryl saddles as a packing material are ineffective. Although the results were found to be inefficient this may have been due to an error in the calculation, or the amount of time per temperature spent collecting the fractions.
A human heart cDNA library was screened with a probe corresponding to the mouse PPARg (7). Three overlapping clones were identified, purified, and sequenced. The nucleotide sequence is shown in Fig. 1. The longest open reading frame starting from the nucleotide at position 91 coded for a polypeptide of 505 amino acids.
Chem 51 LB Experiment 3 Report Scaffold: Bromination of Trans-Cinnamic Acid 1. The goal of this experiment was to perform a halogenation reaction through the addition of two bromides from pyridinium tribromide. This was accomplished by reacting trans-cinnamic acid with pyridinium tribromide. After the reaction took place, melting point analysis was conducted to find out the stereochemistry of the product, which could either be syn-addition, anti-addition, or syn + anti-addition. 2.
The purpose of this experiment is to perform a two step reductive amination using o-vanillin with p-toluidine to synthesize an imine derivative. In this experiment, 0.386 g of o-vanillin and 0.276 g of p-toluidine were mixed into an Erlenmeyer flask. The o-vanillin turned from a green powder to orange layer as it mixed with p-toludine, which was originally a white solid. Ethanol was added as a solvent for this reaction. Sodium borohydride was added in slow portion as the reducing agent, dissolving the precipitate into a yellowish lime solution.
On April 6, 2016 at approximately 11:45am, a local police station got a call about a hostage situation at a local pharmacy. When police and medical examiners got to each crime scene, they learned that all of the hostages were given drugs and had overdosed on them. Some of the pills, in powder form, were found near the victims. One of the victims was stable enough to tell the investigators that the power on the floor were the drugs they were forced to take. The medical examiner found out each hostage was given either unknown A or unknown B.
Nevertheless, the latter is not used in this experiment since it is very reactive and extremely flammable. On the contrary, NaBH4 is relatively mild and it can be used with protic solvents. In this manner, 1.507 grs of the ketone 9-fluorenone were mixed with 30.0 ml of 95% ethanol in a 125 ml Erlenmeyer flask. The bright yellow mixture was stirred during 7 minutes until all the components were dissolved.
The objective of the Bromocresol Green Equilibrium System Lab was to determine if the equilibrium constant, K, was a true constant at constant temperature. To determine this, the value of the constant was found at different concentrations of HIn, HIn-, and at varying pH, which was used to determine the concentration of H+. K was found using the equation K= [HIn]/([In-][H+]). In order to be a true constant, none of the values of K found should differ from the average by more than two standard deviations. The values of K for solutions 1-5 and U were 4.39E4, 4.53E4, 4.23E4, 4.70E4, 6.35E4, and 4.03E4 respectively.
Lab Report Experiment 6 Rates of Chemical Reactions By Nikhola Mirashirova Lab Partner: Dina Abetova Section 3, Saturday October 31, 2015 Introduction Rate reaction is the measure of the change in concentration of the reactants or the change in concentration of the products per unit time.1,2 Rate law for this experiment: Rate = k(I-)m(BrO3-)n(H+)p There are several factors which affect the rate of reaction: catalyst, reactant concentration, and temperature.1,2 A catalyst is a substance that changes, increases or decreases, the rate of a chemical reaction but is not being used up during the reaction.3 It provides an alternative way, so that the rate of reaction changes.4 Catalyst, which is used in this experiment, is (NH4)2MoO (0.5 M).
Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above.
The objective of this lab was to determine the activating strengths of the directing groups in aniline, phenol, acetanilide and anisole by using melting point to identify the products of their electrophilic aromatic bromination reactions with pyridinium tribromide in glacial acetic acid. The amount of substitution in an aromatic compound in a electrophilic aromatic bromination reaction is dependent upon the reactivity of the aromatic compound itself, which is determined by its substituents’ inductive effects. In the case of this experiment, four different aromatic compounds were used, containing either -NH2, -OH, -OCH3, and -NHCOCH3 as substituents. Of these four, the most activating substituent is -NH2 in aniline because nitrogen is less electronegative than the oxygens in -OH and -OCH3 in phenol and
Chapter Vitamin B12 Absorption and Transport in Human Body Omar Abuyaman, MSc Department of Clinical Biochemistry, Aarhus University hospital, Aarhus, Denmark. Abstract Mammals are unable to synthesize B12. Instead, they have a sophisticated multistep pathway for specific and efficient transport of this vitamin from its food source to the target body cells.
Biochemical tests are the tests used for the identification of bacterial species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one species to the other. These differences in carbohydrate metabolism, protein metabolism, fat metabolism, production of certain enzymes and ability to utilize a particular compound help them to be identified by the biochemical tests. Gram’s stain was originally devised by histologist Hans Christian Gram in 1884. Gram-positive bacteria stain purple, while Gram-negative bacteria stain pink when subjected to Gram staining.