The main objective of this experiment was to isolate the compounds in a given mixture, which was composed of 50% fluorene, 42% o-toluic acid, and 10% 1, 4-dibrombenzene. Techniques of extraction and crystallization was used to perform the procedure. The two major compounds in the mixture (fluorene and o-toluic acid) was collected; these were separated by two major methods. The o-toluic acid was extracted first by using macroscale extraction and testing for acidity. By adding a strong acid to the aqueous layer, which contained o-toluic acid, the solution becomes acidic and also allows the solid in the layer to precipitate. Data Tables 1 shows the observations from the acid addition. Though more HCl drops were needed to acidify the second aqueous …show more content…
The percent recovery for the acid was 42%, but there was actually 40% of o-toluic acid in the mixture. The extra 2% could be the impurity, 1- 4-dibromobenzene, which would be isolated in the next experiment. The procedure for removing the acid was performed successfully, though. Data Tables 1 also shows the final results in the isolation of the acid. However, there is a reason more acid was recovered. The acid wasn’t dried completely before it was weighed; the clumpy solids of the acid prove that it wasn’t dried. The extra liquid added to its mass. This could have been prevented by allowing the acid to dry longer, or drying it in an over. Since the volatility of o-toluic acid is almost the same as water, it takes longer to dry at room temperature or it requires high temperatures to …show more content…
This was obtained by techniques of extraction and crystallization. Once fluorene was isolated, it was also crystallized by vacuum filtration. Based on data tables 2, it seemed that the isolation of the neutral compound was a success, because there has been a 50% recovery. However, there was an error: about 0.414 grams of the impure fluorene and impurity was extracted, but 0.475 grams of pure fluorene was found. There has been an addition to the mass of the fluorene during the course of the experiment. This also means that the impurity, 1, 4-dibromobenzene, was not probably extracted completely; it should have been removed during vacuum filtration. However, all the steps for carrying out the extraction of the neutral compound was successful; there were no complications. The error must have occurred during the crystallization procedure. 95% Ethyl alcohol was used as the solvent to dissolve the
To find the mass percent of acetic acid in vinegar, the molar mass of acetic acid is 60.05 g/mole, and 1.00 g/mol of density, then 0.96 mol×(60.05 g/1 mol) = 57.65 g 57.65 g/1000= 0.0576 ×100 = 5.76% The average mass % of acetic acid in vinegar = 5.53% The average % of acetic acid was 5.53%, which is close to the acidity of the vinegar that was taken in the lab which was 5%, for the different percent we had it could be because of errors in calculations or errors in collecting data. 3.
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
By looking at our results, even though my partner and I didn’t obtain a high percent recovery for the unknown, we were still able to identified our unknown to be Acenapthene. We know that our unknown B8 is Acenapthene because of its melting range and its color. The unknown B8 was similar to the color of Acenapthene, and the mixed compound (Acenapthene and the recrystallized compound)’s melting range was close to Acenapthene’s literature melting range. With these two points, my partner and I believed our unknown B8 to be Acenapthene. According to our recrystallized vanillin, we know that our vanillin was pure because of its melting range.
Nonetheless, the light yellow solid was purified by using the recrystallization technique. The formation of o-nitroacetanilide is inevitable and in order to eliminate it, 95% ethanol is used as the solvent of choice. The ortho isomer is soluble in the cold alcohol solution whereas p-nitroacetanilide in insoluble. As a result, the ortho isomer remains in the liquid solution and the final product, the p-nitroacetanilide is isolated with a final vacuum
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.
A drop of bromothymol blue was added to the mixture which serves as an indication if the mixture would be completely neutralized with the addition of 6M sodium hydroxide. Then, 9 drops of 6M sodium hydroxide was added to the flask to neutralize the mixture. A significant color change was
The yellow solution containing the reactants was slowly poured into the beaker containing the cold water and the acid in order to cause the precipitation of the alcohol, 9-fluorenol and to destroy (hydrolyzed) the unreacted excess sodium borohydride. Subsequently, the white precipitate was vacuum filtered and washed twice with 20.0 ml portions of distilled cold water by pouring the liquid into the Buchner Funnel during filtration. It was necessary to wash the alcohol prior to recrystallization considering that the C-OH bond is easily broken by the formation of a stable and benzylic carbocation that favors the synthesis of difluorenyl ether. Finally, before the purification by recrystallization of the obtained product, the white solid alcohol was allowed to dry over a period of a
3. In this experiment, the percent yield was 90%. This number implies that there was little error in this experiment. However, this result could have been caused by certain external factors.
(150.22g/mol)(3.5 x 10^-3 mol of nucleophile) = 0.525 g Actual yield = 0.441 g, Percent Yield = (0.441g/0.525g) x 100% = 84% 10. Percent recovery from recrystallization = (0.172g/0.441g) x 100% = 38% 11.
The actual data is the result on our experiment vs theoretical, which is based on the calculations above. I have also learned to pay more attention to draining out all of the product completely before continuing to test the experiment, as any small drop of contaminant can veer our results into a different
The percent yield was calculated to be 88.1%. Some amount of the product was lost when transferring the product from the Buchner funnel to the balance to measure its mass. To ensure the formation of the desired product, melting point of the product was measured to be 119.8-121.90c, which is in the range of the normal melting point of 2,4,6-tribromoanilne, 120-1220c. Thus, the product was indeed
Additionally, while changing the receiver from cyclohexane to toluene there was a loss of distillate which also led to the errors observed in the data. Furthermore, if more data were collected for each compound it would be a better representation of the experiment's results. If these errors were avoided, then the experiment would be more efficient in distilling the two compounds from each other and the plateau would be as sharp as figure 6 in the lab
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.
That caused a new initial reading of NaOH on the burette (see Table1 & 2). The drops were caused because the burette was not tightened enough at the bottom to avoid it from being hard to release the basic solution for titrating the acid. The volume of the acid used for each titration was 25ml. The volume of the solution was then calculated by subtracting the initial volume from the final volume. We then calculated the average volume at each temperature.
The condensation product between the aromatic aldehydes and the aromatic ketones are 1,3-diphenylprop-2-en-1-ones, which are commonly known as chalcones. If any other types of aldehydes and ketones are used, the product is frequently known as α,β-unsaturated ketones. Chalcones and α,β-unsaturated ketones have been captivating, the medicinal,[1] synthetic,[2] and applied chemists[3] by virtue of their structural units (Figure 1) which have been gained many access to tailor the molecule suitably for wide range of applications in medicinal,[1] synthetic,[2] and applied chemistry.[3] The fluorine has the special topic of interest among the chemists as its introduction into the organic molecules leads to a dramatic changes in their physical and chemical properties.[4] The recent activities show a remarkable growth in fluorine chemistry as the chemists practiced to do polishing the organic molecules with fluorine to improve their properties, leading to widespread applications in medicinal,[4b,c,5] agrochemicals,[6]