The first step is to calibrate the colorimeter with0.20 M Fe(NO3)3and set the absorbance at 470 nm since it is known to keep an acidic solution throughout the entirety of the experiment. It was important to do this right at the beginning of the lab since the zeroed value of the acid was the calibration number for all of the other solutions. A total of seven solutions with different dilutions were used throughout the lab to conduct the equilibrium constant. The first step was adding 5 mL of 0.200 M Fe(NO3)3to each of the 5 test tubes. Once this was done, 0.00200 M NCS was added to the test tubes, each receiving a different amount; test tube one received 1 mL NCS-and with each test tube the amount of NCS-would increase by 1 mL, test tube 5 received 5 mL of NCS. . The next step was adding HNO3 to each test tube in different volumes; Test tube one received 10 mL of HNO3 and with each test tube the amount of HNO3 decreased by 1 mL, test tube five had no HNO3 added to it. The addition of these solutions formed five test tubes of different dilutions, but of equal volume, 10 mL each. After all of the previous trials had been completed the final step was to take each test tube and pour it into a different cuvette and measure the absorbance for each. Once the initial concentration was calculated of Fe3+, NCS and FeNCS2+ in molarity. The absorbency values were recorded and used to calculate the formation constant, K f The reference table containing volumes used in each solution is provided below…
A 125 mL flask was obtained. The square of aluminum was fashioned over the flask by laying the foil over the mouth and folding the sides down. A pin was then obtained and was used to poke a tiny hole in the center of the aluminum cap.…
This particular Diels-Alder reaction exploits an interesting phenomenon. Although aromatic compounds do not normally participate in Diels-Alder reactions, the central ring in anthracene is reactive as a diene. Since all three rings of anthracene can not simultaneously have benzenoid character (Figure 1), the electrons in the pi system of the central ring react more like those of a standard diene. The reaction of the central ring in anthracene allows for the formation of two, independent benzene rings, as seen in the mechanism outlined in Figure 2.…
2. To determine the densities of water, an unknown liquid, a rubber stopper, and an unknown rectangular solid.…
This experiment was performed using techniques of heating under reflux, vacuum filtration, recrystallization, and melting point measurements. These techniques were used to separate the Diels-Alder adduct of the unknown conjugated diene in eucalyptus oil and identify the diene. Dienes contribute to the characteristic flavors and aromas that are found in the essential oils of many plants. Some of these dienes are conjugated and have the ability to make Diels-Alder adducts with maleic anhydride. The Diels-Alder reaction is the conjugate addition of an alkene to a diene. In order for a Diels-Alder reaction to occur the diene must exist as an s-cis conformation and must be conjugated. One reactant (the diene) contributes four carbons and the other reactant (the dienophile, in this case the maleic anhydride) contributes two carbons to the six-membered ring of the resulting cyclic compound (the adduct). This reaction proceeds in one step with no intermediates. This reaction is also stereoselective and yields either of two more stable adduct, an exo or endo. (Lehman, 131).…
Overall, the Diels-Alder reaction of anthracene and maleic-anhydride to form 9, 10-dihydro-9, 10- ethanoanthracene-11, 12-dicarboxylic acid anhydride was a success. The percent yield was 66.3% and the observed melting point range was 258.2-260.3 ℃, affirming that the correct product had formed. Though this experiment was overall successful, it could still be improved: the experimental procedure can be slightly more rigorous which can help in obtaining better quantity and quality of final product. For example, the reaction could be performed on a slightly larger scale that would diminish the error associated with measuring small amounts of reagents. Furthermore, using an air-cooled condenser or running cold water during the reflux would reduce…
Peppermint: Chemical Name Caryophyllene 4H‐1,4‐Epoxy‐4a,7‐ methanonaphthalene, 1,5,6,7,8,8a‐hexahydro‐ , (1α,4α,4aα,7α,7aβ)‐ Cis‐Hydrindane 6‐Methyl‐ bicyclo[4.2.0]octa n‐7‐ol Acetic Acid, Chloro‐, Decyl Ester 3‐ Heptafluorobytyr yloxy‐6‐ Ethyldecane Cornmint: Chemical Name 1,5‐Dimethyl‐1,5‐ cyclooctadiene D‐Limonene 3‐Heptene, 2‐ Methyl‐. (E)‐ 3‐Heptene, 4‐ Methyl‐ Cycloheanol, 5‐ Methyl‐2‐(1‐ Methylethyl)‐ Cyclohexanol, 1‐ methyl‐4‐(1‐ methylethyl)‐ (1.alpha.…
When it comes to organic chemistry and the synthesis of specific products there is an abundant amount of routes that can be taken and still get you the same result. For the following experiment, the main focus is the use of a cycloaddition reaction, also known as Diels-Alder. According to the lab manual, this reaction consists of the addition of a diene and a dienophile and that the Diels-Alder reaction builds stereospecific ring compounds with ease (Weldegirma 80). The reaction takes place between the two pi electrons from the dienophile and the 4 pi electrons from the diene; what happens is the bonds react together in order to form new single bonds because they are more stable, in terms of energetics (Diels-Alder Reaction). In order for the…
.2400 grams of the unknown compound. This is done in duplicate and purple-tinted precipitates are placed in Gooch crucibles. The precipitates are suction dried using ethyl alcohol then acetone to…
The Diels-Alder reaction is one of the most powerful tools used in the preparation of important organic molecules. When two carbon-carbon double bonds are positioned next to one another, a conjugated diene is formed. Conjugated dienes undergo a cycloaddition reaction (also called pericyclic addition) with certain double bonds to afford cyclohexenes and related compounds. The reaction of Cyclopentadiene with Maleic anhydride is an example of a Diels-Alder reaction. This reaction forms a six-membered ring from two reagents: a conjugated "diene" (which provides four of the ring atoms) and a "dienophile" (which provides two of the ring atoms). In this case, the dienophile is Maleic anhydride and the diene is cyclopentadiene. The Diels-Alder reaction is facilitated by the presence of electron donating groups (EDG) on the diene and by the presence of electron withdrawing groups (EWG) on the dienophile. For instance, maleic anhydride is a very good dienophile because it contains two highly electron withdrawing carbonyl groups.…
In this experiment, the cyanide ion served three purposes: first of all, it acted as a nucleophile, then it stabilized the intermediate carbanion, and in the end functioned as a leaving group. The Benzoin produced was then in turn purified and used to synthesize Benzil in the next experiment through Copper (II) ion oxidation. The Benzil was obtained by catalytic oxidation of the Benzoin using the Copper (II) ion as the catalytic oxidant. The Benzil produced was then purified and used as the reactants in the third and final experiment of the sequence which was this one, to produce Tetraphenylcyclopentadienone which is a five-membered carboxylic ring. The Benzil was reacted with 1,3- Diphenylacetone to undergo adol condensation and therefore produce Tetraphenylcyclopentadienone. The first step of the reaction to from the Tetraphenylcyclopentadienone requires the loss of -hydrogen to the base, resulting in a negatively charged carbon that bonds with the carbonyl group from the benzil. The bonding then…
Shen M-R, Batzer MA, Deininger PL (1991) Evolution of the master Alu gene(s). J Mol Evol…
While performing the lab experiments in the first unit, my observation included finding the appropriate tools in the kit in order to carry out the tasks. These experiments really showed me how to differentiate the types of tools we are using and understand the differences and reason for the differences in each. Touch was a big activated sense in these experiments, the heat from boiling the water and the cold ice from the temperature labs allowed for the connection between the results and the way the temperature felt.…
There are twelve key principles of green chemistry that are used to evaluate how green a reaction may be. A green reaction prevents waste before it is created with little to no toxicity. Green experiments should be designed to maximize the starting materials into the final products while minimizing toxicity. Raw materials should be renewable and products should break down and not persist in the environment while reducing derivatives. All experiments should be performed in real time with use of catalysts while minimizing potential chemical accidents.…
The study of the Wittig Reaction is important because it is often used to form alkenes from carbonyl compounds. The purpose of this experiment is to isolate the trans, trans-1,4-diphenyl-1,3-butadiene, which is formed by a Wittig reaction along with the cis, trans isomeric diene. The reaction is carried out in two steps. First the Wittig salt is obtained through a simple nucleophilic displacement of chloride ion by triphenylphosphine. When treated with base, the Wittig salt forms a ylide which is a carbanion that acts as a nucleophile and adds to the carbonyl group. In this experiment, cinnamaldehyde is used as the carbonyl compound and yields mainly the trans, trans-1,4-diphenyl-1,3-butadiene. Purification was done via crystallization. Characterization was analyzed through TLC, UV-vis spectroscopy, and melting point.…