2-Bromohexane Reaction Lab Report

16) Heat some of the hexane to boiling and place the solid to be crystallized into an Erlenmeyer flask.

118℃ and 118-119℃, and 126℃ respectively), when adding heat to the solution, both reactants, 1-butanol and ethanoic acid, will boil and turn into a vapour before the ester, at approximately 118℃. Therefore, their vapour will pass through the Liebig condenser and be condensed back into liquid form to be collected as a distillate before the ester. Only when the temperature reaches approximately 126℃ will the ester undergo this same process and be distilled to obtain an ester distillate. However, as the ester is distilled after the reactants, its distillate can only be collected later as a mixture with the distillates of the reactants. Moreover, as the density of 1-butanol and the ester, 1-butyl ethanoate is very similar (i.e. 0.81gmL-1 and 0.88gmL-1 respectively), it will also be hard to identify the ester layer. Hence, if a distillation set up were used for the production and collection of the ester, isolation of ester as it forms would not be

Cyclohexane (10ml, 7.78g, 0.0924mol) and pyridinium hydrobromide perbromide (9.39g, 0.0294mol) were put into 50ml round bottom flask. The initiator AIBN of 0.1g was carefully added to the flask along with a boiling stone. Simple reflux was setup, and the mixture was refluxed gently for 30mn. White fumes of HBr can be seen on top of condenser can be proven by pH test turning to pink, which indicated that the reactions occurred. Then, the flask was allowed to cool for 15mn. Another small portion of AIBN (0.1g) was added, and

Methylene chloride is added to the flask with the diester. The seperatory funnel is attached to the flask with 1.0 M bromine inside. Bromine is added to ester mixture drop by drop until the solution stays a yellow color. After ten minutes a cyclohexene and methylene chloride mixture is added drop by drop to remove the excess bromine. Ester solution is placed on the rotary evaporator at 45°C. Ethanol was added to the product. Solution was cooled in an ice bath for thirty minutes and crystals began to form. Solution was vacuum filtered with a Hirsch funnel. The mass of the product was 0.47 g. MP 70.1-75.3°C The theoretical yield was .74 g. This makes the percent yield 64%. The expected melting point was 123-125°C. The diacid was not the product formed. With IR, HNMR, and CNMR data the identity of the final product was found. IR (neat) 2989.8 and 2955.7 (Sp3 C-H), 1785.8 (Lactone ester), 1735.8 (ester). 1H NMR (CDCL3) 5.073 ppm (d, 1H), 4.991 ppm (d, 1H), 4.637 ppm (d, 1H), 4.599 ppm (d, 1H), 3.764 ppm (s, 3H), 3.364 ppm ( m, 1H), 3.130 ppm (m,1H), 2.948 ppm (d, 1H), 2.558 ppm (m, 2H), 2.363 ppm ( m, 1H), 1.934 ppm (s, 1H), 1.728 ppm (s, 1H). 13C NMR (CDCL3) 177.037 ppm, 171.388 ppm, 88.171 ppm, 53.125 ppm, 50.270 ppm, 49.297 ppm, 49.328 ppm, 49.040 ppm, 41.317 ppm, 36.441

There was no distillate in the distillation head after 20 minutes on the setting of 40 so the Variac transformer was turned to 45. The first fraction was collected at 55.6°C. The ratio of hexane to octane was 87.437% to 12.563%. The second fraction was collected between 47.3°C and 40.5°C. 88.429% to 11.571% was the ratio of hexane to octane for this fraction. The third fraction was collected at 30.6°C, and the ratio of hexane to octane was 94.957% to 5.043%. The contents of the conical reaction vial were placed in a fourth vial and a chromatogram was obtained for it. The ration of hexane to octane was 7.501% to 92.499%. During the collection of the three fractions, a piece of the glass pipet broke off into the distillation head. The results of the experiment could have been incorrect because the glassware was not properly cleaned. The distillate also could have collected too fast which would have lowered the separations efficiency. From this information, infer that hexane has a lower boiling point than octane because most of the distillate was hexane. The majority of what was left in the conical reaction vial was octane because the temperature was not hot enough to turn it into a gas to go into the distillation

As UV and bromine were needed for the conversion reaction to occur, the mechanism must require light as an energy source and the chemical bromine to occur. The proposed mechanism begins with an initiation step of homolytic cleavage of bromine. When the UV light hit the bromine, highly reactive bromine free radicals formed. In the propagation steps, intermediates were formed; a free Br radical attacked the C=C double bond of dimethyl maleate, breaking the pi bond into a single bond, attaching Br to one of the Carbons, and giving a free radical to the other carbon from the destroyed double bond. Without the pi bond, the Carbons could rotate; one of the esters on the intermediate rotated 180°. Due to steric hindrance, the ester was likely to rotate

With an auto-pipet, 400 l of cyclohexanone was placed into a large sample vial. 1000 l of methanol was added with the cyclohexanone. The sample vial was then capped and the solution was swirled gently. In the hood, 1200 l of sodium borohydride reducing solution was added to the solution by adding it in dropwise. The solution was then swirled and vented occasionally for 25 minutes. After letting it sit and swirling the solution, 4.0 ml of cold dilute hydrochloric acid (1 M HCl) was added into the mixture using a calibrated pipet. The aqueous mixture was extracted with the use of three 2.0 ml portions of methylene chloride. With each addition, the mixture was capped, shook gently, ventilated, and given time for the layers to separate. 2013 mg

A reflux allows for a mixture or compound to be continuously heated and condensed, so that no product is lost to evaporation, while still providing enough activation energy for the reaction to occur. The apparatus is simply a round bottom flask attached to a condenser with a continuous flow of water in and out. In this experiment the reaction

At this point the flask was attached to a refluxing apparatus. This process of refluxing helps to purify the mixture and keep the reaction at a constant temperature. Also, before the reaction mixture began to boil the separation of a clear top layer and a cloudy bottom layer helped to indicate that the reaction was working properly. The top layer was the alkyl bromide since the other components of the aqueous layer have the greater density. After the 45 minute refluxing process was complete, the apparatus was set up for simple distillation apparatus distillation commenced. Distillation took place until no more drops of product were dripping from the distillation head. The first drop of distillate occurred when the thermometer read 75°C, the actual temperature was probably a bit higher since the vapors might not have fully reached the bulb of the thermometer. The final drop of distillate was collected at about 115°C. Once the distillate was collected, it was placed in a seperatory funnel and the reaction flask was rinsed with 10 mL of water and added to the seperatory funnel. Rinsing the funnel ensured that all of the distillate from the distillation process was removed from the reaction flask and no product was left on the walls of the flask. After the water was added, two layers formed in the funnel. The top layer was the water and the bottom layer was the 1-bromobutane since the density of 1-bromobutane is higher than that of water.

Types of Chemical Reactions The purpose of the lab experiment was to identify different types of chemical reaction and the products of the formulas. The different types of chemical reaction include decomposition, single replacement, synthesis, combustion, and double replacement. There were many hazards that were involved in these experiments.

Chemical reactions happen in industrial processes, living systems, and chemical laboratories. These reactions are thought to form products during their processes. These reactions are called combustion, synthesis, decomposition, precipitation, single-replacement, double replacement, acid-base, and redox. Combustion is known as burning. It happens when a substance combines with oxygen, which results in the release of large amounts of energy forming heat and light.

Step 4.) The refluxing was essential in this specific step as we were using an organic substance. This is because by refluxing the solution it allows evaporation to happen at a more successful rate allowing it to be more precise and accurate for when it starts to condense again. This allows the solution to become heated making sure that the

Compared to anhydrous ferric chloride, sodium borohydride is a less reactive reagent and reacts at room temperature. An excess of sodium borohydride was used, and the product of the meso-hydrobenzoin was favored over the production of the racemic mixture of hydrobenzoin. The meso-hydrobenzoin was isolated from the racemic hydrobenzoin through recrystallization since the meso-hydrobenzoin was not resolvable and the racemic mixture was. Separation of the mixtures was performed using filtration. The mass of the meso-hydrobenzoin that was collected was 0.16g, which provided a 21%

In 2.1.1 and 2.1.2, the molarity of solution X is 0.1 M theoretically but after the preparation and calculation, we got 0.083 M. This might occur due to transfer the concentrate HCL into the conical flask excessively as we have to do it in the fume cupboard. Besides, pouring the distilled water more than the line also another factor. There are some precautions that must be follow during using fume cupboard such as the fume cupboard must place away from windows or doors and keep a distance from the fume while perform the work (Dugan,2013). Borax or known as disodium tetraborate was used as a base because it is solid (Sanjeetmanna, 2012) that can be measured easily, odourless, and colourless crystalline that forms from boric acid. Borax insoluble in cold water because cold water can hold less borax than hot water. When it completely dissolved in hot water and reached its saturation point, supersaturation occurred as it cannot

2.10. MTT Assay 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) is a yellow water soluble tetrazolium salt. A mitochondrial enzyme in living cells, succinate-dehydrogenase, cleaves the tetrazolium ring, converting the MTT to an insoluble purple formazan. Therefore, the amount of formazan produced is directly proportional to the number of viable cells.