Radical Halogenation and Gas Chromatography

Discussion: In the synthesis of 1-bromobutane alcohol is a poor leaving group; this problem is fixed by converting the OH group into H2O, which is a better leaving group. Depending on the structure of the alcohol it may undergo SN1 or SN2. Primary alky halides undergo SN2 reactions. 1- bromobutane is a primary alkyl halide, and may be synthesized by the acid-mediated reaction of a 1-butonaol with a bromide ion as a nucleophile. The proposed mechanism involves the initial formation of HBr in situ, the protonation of the alcohol by HBr, and the nucleophilic displacement by Br- to give the 1-bromobutane. In the reaction once the salts are dissolved and the mixture is gently heated with a reflux a noticeable reaction occurs with the development of two layers. When the distillation was clear the head temperature was around 115oC because the increased boiling point is caused by co-distillation of sulfuric acid and hydrobromic acid with water. When transferring allof the crude 1-bromobutane without the drying agent,

During the halogenation reactions of 1-butanol, 2-butanol, and 2-methyl-2-propanol, there is a formation of water from the OH atom of the alcohol, and the H atom from the HCl solution. The OH bond of the alcohol is then substituted with the Cl atom. Therefore all of the degrees of alcohol undergo halogenation reactions, and form alkyl halides as products. This is because the functional group of alkyl halides is a carbon-halogen bond. A common halogen is chlorine, as used in this experiment.

Dichloromethane has a molar mass of 84.93 g/mol. It has a density of 1.325 g/mL at 25°C and a boiling point of 39.8-40.0°C. Dichloromethane is an irritant, a carcinogen, and highly toxic.

The data gathered and calculated in the experiment accurately portrayed the way the reactions would have taken place. The chloride analysis was a little bit off from other groups due to the fact that our AgCl was in clumps, creating less surface area, thus our product took longer to burn and may not have burned correctly compared to other groups; yet there are several experimental factors that could have caused us to have different results than other groups, i.e. different measurements for samples. Our sources of error could have included eye measurement error, timing of set solutions error, measurement errors, and small calculation errors. Among other variables, the calibration of the analytical balance and spectrophotometer could have

The objective of this laboratory experiment is to study both SN1 and SN2 reactions. The first part of the lab focuses on synthesizing 1-bromobutane from 1-butanol by using an SN2 mechanism. The obtained product will then be analyzed using infrared spectroscopy and refractive index. The second part of the lab concentrates on how different factors influence the rate of SN1 reactions. The factors that will be examined are the leaving group, Br – versus Cl-; the structure of the alkyl group, 3◦ versus 2◦; and the polarity of the solvent, 40 percent 2-propanol versus 60 percent 2-propanol.

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.

1. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene.

For the first part of this experiment, six dry test tubes were obtained and labeled accordingly to test the following halides: 2-chlorobutane, 2-bromobutane, 1-chlorobutane, 1-bromobutane, 2-chloro-2-methylpropane, and bromobenzene. To each of the six test tubes 2ml of 15% sodium iodide in acetone was added. 4 drops of the appropriate halide was added to the test tube labeled for that specific halide. After adding the halide, the test tube was then shaken to mix thoroughly. If a precipitate formed the time it took was recorded. Since none of the solutions formed a precipitate at room temperature after five minutes, the test tubes were placed inside of a hot bath at about 50°C. After one minute, the test tubes were taken out of the hot bath and allowed to cool. If any test tubes formed a precipitate, the time it took was recorded on a table.

The free radical chlorination of 1-chlorobutane resulted in a mixture of at least 4 different possible products from the reaction. Gas chromatography-mass spectrometry helped in figuring out which of the products are most abundant in the sample product created as well as in discovering the ratio of relative reactivities of the hydrogens. This experiment showed that the ratio of relative reactivities was found to be 1.0 : 3.5 : 6.2 : 2.4, which indicates that the secondary hydrogens are more reactive than the primary hydrogens and that reactivity further increases the further away the hydrogen is from the chlorine on the 1-chlorobutane. The results agree with the conjecture that the primary hydrogens are less reactive than

The products of interest within this experiment are 2-methyl-1-butene and 2-methyl-2-butene from sulfuric acid and phosphoric acid catalyzed dehydration of 2-methyl-2-butanol. The reaction mixture was then separated into its separate alkene components by steam distillation and then analyzed by gas chromatography (GC), Infrared Radiation (IR) spectroscopy, and Nuclear Magnetic Resonance (NMR) imaging. Gas chromatography is an analytical technique that is able to characterize if specific compounds exist in a reaction mixture, even if they are in low quantities, assess how much of a compound exists within a reaction mixture relative to other components within the sample, and determine the purity of an isolated product. In the case of this experiment, gas chromatography is used to analyze how pure the alkene reaction sample was and if any remnants of impurities or 2-methyl-2-butanol remained in the sample after isolation of alkene components.

Distillation is a method of separating two volatile chemicals on the basis of their differing boiling points. During this lab, students were given 30 mL of an unknown solution containing two colorless chemicals. Because the chemicals may have had a relatively close boiling point, we had to employ a fractional distillation over a simple distillation. By adding a fractionating column between the boiling flask and the condenser, we were able to separate the liquids more efficiently due to the fact that more volatile liquids tend to push towards the top of the fractionating column, thereby leaving the liquid with the lower boiling point towards the bottom. After obtaining the distillates, we utilized a gas chromatograph in order to analyze the volatile substances in the gas phase and determine their composition percentage of the initial solution. Overall, through this lab we were able to enhance our knowledge on the practical utilization of chemical theories, and thus also demonstrated technical fluency involving the equipment.

The purpose of the experiment is to oxidize a secondary alcohol (2-octanol) by using sodium hypochlorite (bleach) to produce 2-octanone. The starting material consisted of a sample of 2-octanol that was placed into a three-neck flask along with acetic acid and acetone creating an acidic solution. While monitoring temperature fluctuations to ensure a temperature of 400 Celsius was not reached, sodium hypochlorite slowly dripped from a separatory funnel into the acidic solution. Once this reaction reached its entirety, the solution was combined with sodium bisulfate to remove any of the remaining oxidizing agent. This solution was then tested and brought to a neutral pH using a sodium hydroxide solution. The reaction material was extracted using ether and was then washed with a saturated sodium chloride solution. The organic solution was then dried using magnesium sulfate and was then decanted and placed onto the rotovap. The produced weighed .599g and based on the infrared spectrum analysis (see Figure 1) preformed on the product it was determined to be 86.1% 2-octanol, which means .516g of 2-octanol was obtained in the final product.

Even though the result of an experiment is accurate and matches the literature value, it does not mean that there were no mistakes made. As the difference of the percentage uncertainty and the percentage error suggests there were random errors made. First of them was the heat energy lost to the surrounding environment during the experiment process taking place. This caused the recorded highest temperature to be smaller than the actual highest temperature that was meant to reach. This could have been prevented by adding in more and perfect

Methane production from hydrogen and ethanol effluent was conducted. The effect of effluent concentration and trace element addition was investigated. All of experiment was done in triplicate using serum bottle. The serum bottle was cap with rubber stopper and aluminum cap then flushed with N2 gas to create anaerobic conditions, and placed in an incubator at the room temperature. During the incubation period, gaseous and liquid samples were taken and

This lab consisted of the conversion of alcohols into alkyl halides through common substitution methods. These methods include SN1 and SN2 mechanism, both of which can occur for this type of reaction. For both reactions, the first step of protonation will be to add hydrogen to the –OH group and then the rest of the reaction will proceed according to the type of mechanism. SN1 reactions form a cation intermediate once the H2O group leaves, then allowing a halide (such as Br) to attack the positively charged reagent1. On the other hand, SN2 reactions are one-step mechanism in which no intermediate is formed and the halide attaches as the leaving