The goal of this experiment was to isolate three different molecules (acidic, basic, and neutral) from a mixture and identify their molecular structure. This was accomplished by using acid/base liquid extraction and H NMR analysis. The neutral component of the unknown mixture #191 was fluorenone. This was evident due to an H NMR spectra that had a high presence of hydrogen signals in the 7.2- 7.7 ppm range. Chemical shift values for fluorenone stated in the lab manual were 7.27, 7.47, 7.48, and 7.6 (CITE), indicating that the corresponding H NMR spectra for the neutral unknown is of this chemical. The other possibility for the unknown neutral, 1,4-dimehtoxybenzone, would have had an H NMR spectra with two peaks; however, the spectra obtained did not show chemical shifts for an aromatic ester group and had many hydrogens in the aromatic …show more content…
When comparing the neutral unknown to the unknown mixture, there is a prevalent overlap in the aromatic hydrogen ppm range, presenting a distinct correlation between my isolated neutral and the mixture containing this chemical. Another indicator that was used to determine the identity of this neutral chemical was the melting range, which was tested to be 68.7 C to 71.5 C. The literature value for fluorenone is 80 C to 83 C (CITE), indicating that my compound was slightly contaminated. However, the melting point range for 1,4-dimehtoxybenzone is 57 C, and therefore, it can be concluded that the neutral compound isolated was indeed fluorenone. The contamination that caused this depression in melting point was likely due to acetone, which appeared on the H NMR spectra. Also, when weighing the watch glass after evaporating the ether the yield was not as high as predicted. Upon removing the fluorenone from the watch glass and re-weighing, a much more reasonable yield of 52 mg or 52% recovery was obtained. This discrepancy in weighing led to
This aqueous solution was then heated until all the dichloromethane evaporated off. An error could have occurred at this point in the experiment if the hot plate was too hot. If the hot plate was set above the boiling point of the ketone, the ketone could have evaporated of along with the dichloromethane. This would result in a lower percent yield of the ketone. To prevent this from happening, the hot plate should not exceed 130˚C, so no matter what ketone was isolated, it would not evaporated off.
Chemistry 1051 Portfolio Over my time in chemistry 1051, I have learned many valuable lessons, and skills. Accurate recording of data was one of those skills, as was creating a well-organized lab write up that correctly laid out the process we completed. During the very first lab we were also given the task of creating our own method to test the density of a peace of glass. We decided to both measure and weigh the glass, effectively testing the density, and afterwards critiquing both methods and choosing the most effective one.
Identification of an Unknown Compound using Quantitative and Qualitative Analysis Lauren Tremaglio Chemistry 1011 Lab, Section 16 Instructor: Steven Belina October 3, 2014 Our signatures indicate that this document represents the work completed by our group this semester. Experimental Design and Discussion of Results The objective of this experiment was to identify an unknown compound through quantitative and qualitative analysis. In order to find the identity of the unknown compound, an initial qualitative test for solubility was performed.
Unknown Lab Report Unknown # 25 By: Jenna Riordan March 19, 2018 Bio 2843 1. Introduction Microbiology is the study of microorganisms found in all different environments throughout Earth, from the hot thermal vents at the bottom of the ocean to the ice at the top of a mountain.
The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst.
Even though we had a strong smell of banana, but there was the presence smell of some other compounds as the NMR spectrum shows (see attach sheet). This showed that the product obtained was not completely pure due to the extraction or distillation process, but not to forget that it can also be due to the unclean of materials. The NMR data was consistent with the one expected for the product, where the CH bond was deshield, and the CO bond the shield, but not the least shield (see attach sheet). Conclusion
The purpose of this experiment was to identify the two components of an unknown mixture through diverse experimental techniques such as recrystallization, extraction, melting point, and acid-base reactions. From this, the group to which these two compounds belong to had to be determined. These groups are: Carboxylic Acids, phenols, and neutrals. By determining the melting points of the two unknown compounds, these values were compared to the values of melting points in the chart and the proper compound was selected. For the case of this experiment, the unknown mixture contained, 4-methylbenzoic acid.
Elijah Brycth B. Jarlos IX-Argon 1. Multicellularity is a condition of an organism to have multicellular cells. An example of a organism who has multicellular cells are plants, animals, and humans. The main reason of why scientists have a hard time finding a good set of existing organisms to compare. Is neither the first set of organisms which is being compared is dying as fast as the second specimen is being examined or they just can’t find the right species.
We identified unknown A as acetaminophen. This is because unknown A had all the same tested properties as acetaminophen when we performed our tests. For unknown B we found it to be acetaminophen and caffeine. This is because like unknown A, unknown B properties were the same as acetaminophen, but unknown B was acetone soluble. Unknown B has similar properties to caffeine because it was acetone soluble and because caffeine was the only basic pH tested to change color during the FeCl3 test.
Leah Romero 10/30/2017 Conclusion Lab 3 Chem 102L In lab 3, fundamentals of chromatography, the purpose was to examine how components of mixtures can be separated by taking advantage of different in physical properties. A huge process in this lab was paper chromatography, which was used to isolate food dyes that are found in different drink mixes. The different chromatograms of FD&C dyes were compared to identify which dyes are present in each of the mixes.
The purpose of this experiment was to learn about metal hydride reduction reactions. Therefore, the sodium borohydride reduction of the ketone, 9-fluorenone was performed to yield the secondary alcohol, 9-fluorenol. Reduction of an organic molecule usually corresponds to decreasing its oxygen content or increasing its hydrogen content. In order to achieve such a chemical change, sodium borohydride (NaBH4) is used as a reducing agent. There are other metal hydrides used in the reduction of carbonyl groups such as lithium aluminum hydride (LiAlH4).
Unknown Lab Report Mikee Lianne Gonzales Biol 351- 1005 Holly Martin Unknown: # 76 Abstract This report is about identifying the respective genus of the given unknown organism. The goal is to show and prove the student’s understanding of microbiology and laboratory learned experimental techniques.
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.
This supports the isolated product is majority made of the desired product and is largely pure. Mass spectrometry of the crude product shows the molecular ion peak is 162.1, which is the largest fragment in the mass spectrum (Figure 4) and corresponds to the molecular weight of methyl trans-cinnamate (Table 1). The base peak is 131, inferring the fragment lost is 31 m/z in size. This 31 m/z matches the OCH3 fragment of the ester, and would not result from a trans-cinnamic acid. This is evidence the product was successfully
This was proved by utilizing the IR spectrum to verify the C =O was not in the final product as it lacked the 1640 cm-1 peak. The melting point of 113-115 degrees C proved that the final product obtained was the E-Stilbene. The TLC plate proved that the E and the Z product was produced, show cased by the double intensity of the DCM spot to the final product’s spot, both which had an Rf of 0.92. The double intensity proved that both products were produced, but through heating and filtering, the Z-Stilbene was