TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.
The percent yield was 22.33%. In most cases, that means that a lot of possible product was lost. However, in this case, that was not true. When Benzaldehyde reacted with the Wittig reagent, it produced two products: E-Stilbene and Z-Stilbene. The Z product was a liquid, while the E product was a solid.
One error that could have affected the percent yield is not filtering out all of the liquid from the filter paper in the funnel before setting it off to dry. This would have increased the final mass of the solid, not making it accurate. To stop this from happening again, the liquid could be drained more thoroughly until it fully stops dripping into the Erlenmeyer flask. Another error that could have affected the percent yield is the amount of trials performed. This would have made the results less accurate and made any errors change the final results even more.
Polar molecules will spent most of the time moving with the solvent because there will not be as much as attraction between the hydrocarbon chains attached to silica and the polar molecules in the solution. About the non polar mixtures, because of the Van der Waals forces will tend to form attractions with hydrocarbon
If the two ions are mixed in solution, a precipitate will tend to form. If steps have been taken to remove ions that form competing precipitates, the presence of a properly colored solid can be used to confirm the presence of a given ion. If several different precipitates remain, the conditions of the solution can be manipulated to selectively redissolve one or more of the solids. When the equilibria involved are well understood, selective precipitation can be a powerful tool in the identification of unknown
They found that carbon dioxide needed to be activated to build hydroxybenzoic acids with alkali metal phenoxide. They came to this realization by coordinating the alkali metal with the carbon dioxide. This caused the formation of the MOPh-CO2 complex. As the carboxylation reaction proceeded, a direct carboxylation of the benzene ring with another molecule of carbon dioxide did not take place, instead, the CO2 moiety of the MOPh-CO2 complex performed an electrophilic attack on the benzene ring in the ortho and para positions.
This is due to the boiling points of the two compounds are too close for an effective simple distillation. A simple distillation only works when the boiling points of the two compounds are separated by at least 50 °C (CITATION). Meanwhile, the boiling points of the compounds of the mixtures are 82.3 °C for 2-pronanol and 117 °C for 1-butanol (National Center for Biotechnology Information). As well, while fractional distillation is more difficult due to the added fractionating column and insulation, it allows for better separation and condensation of the individual compounds.
In order to complete the synthesis, the other hydroxyl group present in morphine must also undergo the above steps. Diamorphine is then formed. The HCl that was made in the process reacts with the basic tertiary amine group on diamorphine to form its hydrochloride salt derivative. This above reaction could also have been carried out with acetic anhydride instead of acetic chloride.
A ﬂow sheet giving the diﬀerent approaches for pretreatment of waste cooking oil is shown in Figure 2. Issariyakul et al. Have reported the treatment of waste cooking oil using centrifugation for the removal of solid portions of the oil. Water was
Excess or lesser amounts of 1.00 M NaOH can lead to inappropriate standardization. Consequently, an incorrect standard solution prepared yielded to the wrong number of moles of NaOH which consequently give us wrong data. Another issue arose with the amount of the indicator used. Since drops are the measurement associated with the amount of phenolphthalein, it is quite difficult to obtain an accurate amount. A slight error in the indicator can shift the endpoint and consequently affects the volume of the obtained NaOH.
Also, the capillary tube may have been contaminated. This lead to nearly identical marking on the TLC plate and similar Rf values. Due to this, it is not possible to conclude whether or not acetaminophen was separated from the sample of Excedrin. The Rf value of the pure isolated caffeine was 0.28. This was 0.16 higher than the Rf value of the pure caffeine.
Based on the obtained results from the experiment, the unknown liquid was determined to be methanol. The results were very close to the theoretical values, all within 15.92 % error. In this experiment it showed that the methanol have different intermolecular forces at work and at different vapor pressures implying that the amount of intermolecular forces they exhibit affects the vapor pressure. Possible source of error that occurred throughout the experiment was that the temperature was hard to control leading to the variances between the temperature of the reading in the water bath and the actual temperature causing slight changes in the vapor
When determining the solubility of malonic acid in different solvents both water and methyl alcohol were found to be polar when mixed with malonic acid. Hexane however was insoluble. Lastly biphenyl was mixed with water and was found to be insoluble, methyl alcohol was determined to be partially soluble. Hexane on the other hand was the only soluble solvent for biphenyl 2. Part B. of this experiment determined the solubility of different alcohols in hexane or water.
In order for a substance to be pure, its melting point, from start to finish, must stay within 3 oC or 4 oC because more pure organic substances melt within the range of 1 oC – 2 oC. (Craine et al., 2012) The range of the crude was 5.3 oC, a clear indication of impurity. In addition, it was well below the literature melting point of 9,10-dihydroanthracene-9,10-α,β-succinic anhydride at 262 oC – 264 oC, which was another indication of impurity. However, the pure product had a melting point of 260.3 oC – 263.9 oC, which was much closer to the melting point of the pure product and stays within the range of 3 oC – 4 oC, which could indicate that there was still a small amount of impurity, but the product attained was close to a pure
so that means that the longer chain will have a slow reaction. It does not have a color and it does not cause fires to happen. It may burn the skin because it is a corrosive substance which is why you should wear gloves when you are handling it. If you swallow the hydrogen chloride then it can be dangerous because it is a toxic substance The bonding in hydrogen chloride is called covalent bonding because nonmetals and metals have the capability to react