Addition reactions allow the reaction of two or more reactions to form into the adduct (the larger molecule formed). However, this only applies to compounds that have multiple bonds, for instance a double or triple bond. In this experiment, the reaction will be an addition of HBr to 1-hexene (an alkene). Both reactants are in reflux, which allows one to determine whether 1-bromohexane or 2-bromohexane is formed. In the reflux setup, 0.5 mL of 1-hexene, 2 mL of 48% HBr (aq), and 150 mg (0.15g) tetrabutylammonium bromide is added and then heated for two hours, along with stirring (using a spin vane). The reactants must be continuously stirred in order to mix the HBr and 1-hexene, since they are immiscible. It is also used to prevent bumping; …show more content…
The mixing in this step allows all the reagents to mix thoroughly and is vented to release pressure inside the funnel. After the mixture is left still, it will separate into an organic layer and an aqueous layer. In this experiment, the bottom layer was aqueous and the top was organic. The bottom layer was removed and 10% sodium bicarbonate was added to the organic layer left in the separatory funnel. The sodium bicarbonate is used to extract the organic layer again. The organic layer is then dried with Na2SO4 salts and filtered through a gravity filter (cotton in short-stem glass funnel). The filtered portion is placed in a vial and then placed on top of the steam cone in order to remove excess moisture. After an approved amount of solution is left in the vial, it will be set aside to perform the silver nitrate and sodium iodide tests. Three test tubes were used for each test, representing the different solutions of interest—10 standard, 20 standard and the solution created from the experiment. For the silver nitrate test, there is to be 2 mL of 0.1M solution of silver nitrate in 95% ethanol in the test tubes. Then 1-2 drops of the solutions of interest are placed in the test tubes. The following reactions are expected for the silver nitrate
Next rinse the funnel with cleaning solvent to ensure all impurities in the solvent are removed.
In part A, the Grignard reagent was created. Mg is added between the benzene ring and the bromine by means of a non-chain radical reaction. Initially, Mg donates and electron to bromide and heterolytically breaks the C-Br bond; therefore, this results in a carbon radical, Br - ion, and a Mg+ radical. Next, the carbon radical and the Mg+ radical bond together, and the Mg and Br - ionically bond together2. In the experiment, no initial color change to cloudy gray was observed. Eventually, it was decided to try and
The empirical formula for silver oxide for trial one is Ag5O4 and for trial two is Ag3O2. For trial one there is 0.451 grams of silver were produced from 0.504 grams of silver oxide. For trial two there is 0.456 grams of silver were produced from 0.500 grams of silver oxide. The difference between the mass of silver oxide and mass of silver is the mass of oxygen that vaporized into the air. There are 0.053 grams of oxygen vaporized into the air for trial one and 0.456 grams’ oxygen for trial two.
The crude product was washed by taking the reaction product in the separatory funnel and adding 23 mL of deionized H2O. The mixture was shaken and allowed to settle until layers were observable. The top layer was the desired product and approximately 25 mL of aqueous layer was extracted from the separatory funnel. Next, 25 mL of 5% NaHCO3 was added to the separatory funnel in order to neutralize the acid. This mixture was swirled, plugged with the stopper and inverted. Built-up gas was released by turning the stopcock to its opened and closed positions, releasing CO2 by-product. This was done four times in one minute intervals. The solution was allowed to settle until layers were observable. The bottom layer that contained salt, base and water was extracted from the separatory funnel. The crude product was washed again as mentioned previously.
The purpose of this experiment is to distinguish the relationships between reactants and products, in addition to expanding on concepts such as single displacement reactions, mole ratio values, moles to mass, theoretical yields, limiting reactants, excess, stoichiometric relationships and percentage errors.
The purpose of this experiment is to distinguish the relationships between reactants and products, in addition to expanding on concepts such as single displacement reactions, mole ratio values, moles to mass, theoretical yields, limiting reactants, excess, stoichiometric relationships and percentage errors.
3. Carefully felt the sides of the test tube and observed the resulted chemical reaction for about 30 seconds.
As the acid was being added, the mixture was being stirred over a stir plate. Once completed, the reaction mixture was poured from the round bottom flask into a 500 mL separatory funnel and its top (organic) layer was extracted into another beaker. The bottom (aqueous) layer was placed back into the funnel and extracted twice with 50.0 mL of ethyl ether each. The newly extracted layers were combined and dried over magnesium sulfate (MgSO4). The dried solution was the decanted into a beaker to remove the MgSO4 salts and the product solution was collected via Buchner vacuum filtration. The resulting product was transferred into an Erlenmeyer flask with an inverted beaker on top and stored in a drawer.
In the separating funnel, a heterogeneous mixture was formed: resulting in an organic layer (top) and a solvent layer (bottom). This effectively allowed the draining of the solvent, in order to isolate the organic layer, the impure ester (1-pentyl ethanoate)
Determining how a mechanism comes to be is crucial as a scientist and arriving to conclusions is a crucial component which lead to examining and determining which mechanism takes place when two or more substrates are made to react. At the end of the experiment a mechanism was determined based on the purified product’s melting point. This was accomplished by having the reaction take place but also through acquiring the melting point and comparing the number to the melting point which was already established by the scientific community. (Q1) When 0.252 g of trans-cinnamic acid was mixed in 2.5 mL glacial acetic acid and 0.434g pyridinium tribromide was added, the resulting product reflects an addition reaction. In general, reactions take place to achieve its lowest Gibb’s free energy because it’s at
By heating to refluxing, the temperature and thermal energy were controlled during the experiment. Heating the reaction is important because it is required in order for the bonds to break to cause a chemical reaction. Breaking bonds also means requiring energy and that is where activation energy comes into play. All chemical reactions has to overcome an energy barrier to generate the product from the reactant.
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,
When the crude product is transferred to a separatory funnel, it is washed with 10 ml of water. When the solution forms two layers, the bottom aqueous layer is disposed of.
14 mL of 9 M H2SO4 was added to the separatory funnel and the mixture was shaken. The layers were given a small amount of time to separate. The remaining n-butyl alcohol was extracted by the H2SO4 solution therefore, there was only one organic top layer. The lower aqueous layer was drained and discarded. 14 mL of H2O was added to the separatory funnel. A stopper was placed on the separatory funnel and it was shaken while being vented occasionally. The layers separated and the lower layer which contained the n-butyl bromide was drained into a smaller beaker. The aqueous layer was then discarded after ensuring that the correct layer had been saved by completing the "water drop test" (adding a drop of water to the drained liquid and if the water dissolves, it confirms that it is an aqueous layer). The alkyl halide was then returned to the separatory funnel. 14 mL of saturated aqeous sodium bicarbonate was added a little at a time while the separatory funnel was being swirled. A stopper was placed on the funnel and it was shaken for 1 minute while being vented frequently to relieve any pressure that was being produced. The lower alkyl halide layer was drained into a dry Erlenmeyer flask and 1.0 g of anhydrous calcium chloride was added to dry the solution. A stopper was placed on the Erlenmeyer flask and the contents were swirled until the liquid was clear. For the distillation
The purpose of this experiment is to synthesize 1-bromobutane from 1-butanol and sodium bromide. In order for this reaction to reach completion there are four major operations that need to be performed. The four major operations include refluxing, simple distillation, separation, and drying.