Conclusion In this lab, the reactivities of different types of hydrogens, including primary, secondary, tertiary aromatic, aliphatic, and benzylic hydrogens, were analyzed. The experiment was conducted twice, simultaneously. One set of test tubes containing bromine, dichloromethane, and one of toluene, ethylbenzene, tert-butylbenzene, cyclohexane, methylcyclohexane, or more dichloromethane (control), were exposed to UV light; the other equal set of test tubes were placed in a fume hood with the light off. This set of test tubes was not fully in the dark. Once the bromine was added to each test tube, the color of each test tube was monitored, and the time that a color change occurred in each test tube was noted. Bromine is red; when the solution was no longer red, it could be understood that the reaction had taken place. For the test tubes exposed to UV …show more content…
Methylcyclohexane became clear within about 28 minutes, cyclohexane was clear in about 55 minutes, and both the control and the tert-butylbenzene did not appear to change color. The dark test tubes changed color in the same order. Ethylbenzene became clear within about a minute, toluene became clear within 2 minutes, and methylcyclohexane was very light orange (almost clear) in 65 minutes. Cyclohexane, tert-butylbenzene, and the control were all still red, and had not appeared to have reacted. These results were expected; ethylbenzene and toluene had benzylic hydrogens, meaning they should be the fastest, which they were. Ethylbenzene also had
Observations The purpose of this experiment was to be able to synthesize triphenylmethyl bromide from triphenylmethanol by a trityl carbocation intermediate. During the experiment, 0.100 g of triphenylmethanol was placed into a small test tube. The triphenylmethanol looked like a white powder. Next 2 mL of acetic acid was added to the test tube and the solution turned a cloudy white color.
Something that was interesting to find out though, in the description of the reagent color test they show the lighter color on top and the darker one on the bottom. But just as the test that was conducted showed and what Officer had said was that the darker color is always on the top and the lighter on
To test for the presence of the ammonia cation, a scoop of the unknown compound was mixed with NaOH to see if the resulting solution had a noticeable smell that would affirm the presence of ammonia. A moist piece of pH paper was then held near the solution to see if the ammonium would dissolve the water on the pH paper. The next cation test performed was the flame test. A gram of the unknown compound was held by a metal stick above the flame of a Bunsen burner to see what color flame the compound would produce. The chart in the lab manual on page 63 was used to determine what cation correlated with what flame color.
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.
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.
Benzyne Formation and the Diels-Alder Reaction Preparation of 1,2,3,4 Tetraphenylnaphthalene Aubree Edwards Purpose: 1,2,3,4-tetraphenylnaphthalene is prepared by first producing benzyne via the unstable diazonium salt. Then tetraphenylcyclopentadienone and benzyne undergo a diels-alder reaction to create 1,2,3,4-tetraphenylnaphthalene. Reactions: Procedure: The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial.
However, after refluxing for a while, yellow precipitates begin to form near the top of the flask. It was assumed that the remaining starting material was concentrated from a decrease volume to reappeared in solution. Nevertheless, this may have been a sign of contamination that will negatively affect the entire reaction. This observation later resulted in a yellowish
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.
Abstract – Methyl trans-cinnamate is an ester that contributes to the aroma of strawberry. It can be synthesized by an acid-catalyzed Fischer esterification of a methanol and trans-cinnamic acid under reflux. The solution was extracted to obtain the organic product, and evaporated residual solvent The yield was 68%, but there is some conflicting data regarding the purity. The melting point, IR, GC-MS indicate a highly pure desired product whereas 1H NMR shows there are unreacted reagents still present.
This shows that the methylene blue was not reduced because no color change occurred and that the methylene blue did not gain any electron, so it did not function as a substitute for oxygen as the final electron acceptor. The tube that contained the MgCl2 solution showed a slight color change which means that the methylene blue was slightly reduced. The reason why there were not reduced is maybe because the enzyme found in yeast which is the dehydrogenase was inhibited; the yeast is therefore incapable of carrying out one or more stages in the transfer of hydrogen to methylene blue in order to be reduced.
Benzene, hydrogen and recycled cyclohexane with platinum catalyst contains low sulfur poisoning while nickel catalyst are permanently poisoned by sulfur.()Cyclohexane from petroleum is a complicated process which yields 85 wt. % purity. It is not a widely used method due to the close range of boiling points between byproducts dimethyl pentanes in natural cyclohexane concentrate. “It’s impractical to produce high purity yield.” () Physical and Chemical Properties Cyclohexane is a highly flammable liquid. It is colorless, mobile, water-insoluble, non-corrosive, easily vaporized and less toxic than benzene.
Dependent The time taken for the bluish -black color to fade away (color of Iodine solution mix with starch solution ). The rate of enzyme reaction Minutes (min) Table 1.1 – Table shows the controlled variables in the experiment variables Units Measures of controlled variables.
Use these results to determine the product concentration, using Beer-Lambert’s Law: A= ɛCl (where A is the absorbance, ɛ is the molar absorptivity, C is the product concentration and l is the length of solution that the light passes through). Calculate the product concentrations at every minute for 10 minutes for all 7 of the test tubes using Beer-Lambert’s Law. Plot a graph of product concentration vs. time and then use the gradients of the 7 test tubes to determine the velocities of the reaction. After calculating the velocities, plot a Michaelis-Menten graph of velocity vs. substrate concentration.
Introduction The term chromatography actually means colour writing, and signifies a technique by which the substance to be examined is placed in a vertical glass tube containing an adsorbent, the different segments of the substance traveling through the adsorbent at distinctive rates of velocity, according to their degree of attraction to it, and producing bands of colour at different levels of the adsorption column. The substances least absorbed emerge earliest; those more strongly absorbed emerge later. (Wixom et al., 2011) In chromatography of all types, there is a mobile phase and a stationary phase.
Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.