Mixture Of Ortho And Para Nitrophenol Lab Report

The main goal of this lab was to determine which of the acetaminophen and acetylsalicylic acid exists in Anacin and which exists in Tylenol. In order to achieve this goal, Thin Layer Chromatography, an approach that uses the difference in the strength of intermolecular forces and polarity in molecules to separate mixtures, was used

2. The TLC results showed two different spots that traveled different distances on the TLC plate, one for ethyl vanillin and one for ethyl vanillin alcohol which proves there is no evidence of the starting material in our final product. The product (ethyl vanillin alcohol) was more polar and interacted more with the solvent than our starting material (ethyl vanillin). This increase in polarity is due to the extra alcohol group in the ethyl vanillin alcohol and the smaller Rf value also indicates it is more polar and pure than the ethyl vanillin.

The isosbestic point of the acid (pH6) and basic forms (pH10) of para Nitrophenol (PNP) was expected at 350nm. As you can see in figure 2, the graph shows the intersection of 2 curves at ~350nm, which is matched with the literature value. Also, the pKa of PNP was expected 7.15 at room temperature. Refer to figure 3, the pKa is estimated to be 7.15-7.2, which very close to the literature value. In addition, the lab was succeeded in illustrating the use of a spectrophotometry to analyze concentrations of chemical substance. The absorbances of 2 unknowns were felt on the standard curve as the expectation (refer to table 4). The minimum absorbance of the known standards was 0.193 and the maximum is 1.830. The absorbance of the unknown

This was concluded by combining information on melting points and TLC; melting range narrowed when filtered product was mixed with the standard product. Also, the Rf value of the pure product is closely related to the Rf value of the standard. TLC of filtrate showed no movement of the substance in the mixture under 9:1 ratio declaring the substance to be extremely polar. Of the three potential unknown reactants, 4-methoxyphenol would be the most polar and therefore would travel least up the TLC plate. (Q14:Yield) 81.2% product yield was collected. “Matter cannot be created nor destroyed”, therefore some product could have filtered through. TLC of filtrate confirmed remnants of product present. Filtering the filtrate could have increased the yield. (Q15:Recovery) The percent recovery of the product makes sense because it is the mass of the crystallized product divided by the crude product: 94.9%. The percentage reflects the mass of pure product (without the presence of impurities). (Q16:MP) Melting point coincides with the unknown nucleophile being 4-methoxyphenol because when the standard product was combined with our pure product, the melting range narrowed. When compared to the melting ranges obtained when mixed with the other two possible products the melting ranges significantly decreased and widened. This is often an indication of impurities being present, but because this was a

The goal of this was to successfully accomplish the synthesis of para-Chlorophenoxyacetic acid. In this experiment, para-Chlorophenoxyacetic acid was synthesized from 4-chlorophenolate and chloroacetic acid using an SN2 reaction. The product obtained was determined to be the para isomer of Chlorophenoxyacetic acid. This was confirmed by the melting point of 157.3-157.9 ◦C. The percent yield determined at the end of the experiment was 37.83 %. The TLC analysis showed that P-Chlorophenol was less polar than P-Chlorophenoxyacetic Acid because it had an Rf value of 0.38 in comparison to the value of 0.33 on a 50:50 hexane and ethyl acetate solvent mixture. In the NMR comparison, it was shown that both the starting material of chloroacetic acid and product contained a peak of integration two around 4 ppm representing the acidic proton. In the FT-IR comparison, it was determined that the Chloroacetic acid and the para-Chlorophenoxyacetic acid both had an OH bond at 3416 cm-1 and 3429.72 cm-1 respectively. The Chloroacetic acid and para-Chlorophenoxyacetic acid also both had a carbon-oxygen double bond at 1648 cm-1 and 1654.81 cm-1 respectively. The para-Chlorophenoxyacetic acid also contained a peak at 1236.18 cm-1 which represents the C-O-C bond.

6. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene; to purify the crude product of either trans-stilbene, cis-stilbene, or styrene reaction.

In the first part, there may have been cross contamination of materials, especially since periods before us had already performed the experiment. During chromatography, our spot sizes were initially very varied, as we didn’t know exactly how much of each substance to place when we began. Thus, the substances in more abundance would have greater opportunity to travel up with the eluent, skewing the results. In the beginning, we even put 6-7 drops, causing some of the substances to mix together. Touching the TLC plate may also have disrupted some of the substances traveling up.

From the results that were acquired from mixing the liquid reagents with each powder, it was determined that Unknown Mixture #1 consisted of baking soda and cornstarch. When individually testing the substances from Unknown Mixture #1 with the liquid reagents, a few noticeable reactions occurred. Mixing baking soda with vinegar caused bubbling to occur. This is because a neutralization reaction took place between the two reactants. In this reaction, sodium bicarbonate(baking soda) reacts with vinegar and produces sodium acetate, water, and carbon dioxide(HC2H3O2(aq) + NaHCO3(aq) NaC2H3O2(aq) + H2O(l) + CO2(g) ). The gaseous carbon dioxide most likely tried to escape into the atmosphere and caused the bubbling to occur. Another noticeable reaction

In this experiment, 0.31 g (2.87 mmol) of 2-methylphenol was suspended in a 10 mL Erlenmeyer flask along with 1 mL of water and a stir bar. The flask was clamped onto a hotplate/stirrer and turned on so that the stir bar would turn freely. Based on the amount of 2-methylphenol, 0.957 mL (0.00287 mmol) NaOH was calculated and collected in a syringe. The NaOH was then added to the 2-methylphenol solution and allowed to mix completely. In another 10 mL Erlenmeyer flask, 0.34 g (2.92 mmol) of sodium chloroacetate was calculated based on the amount of 2-methylphenol and placed into the flask along with 1 mL of water. The sodium chloroacetate solution was mixed until dissolved. The sodium chloroacetate solution was poured into the 2-methylphenol and NaOH solution after it was fully dissolved using a microscale funnel.

0.300 grams of biphenyl/ p-toluidine sample was weighed. Next, 10 mL of dichloromethane was measured in a graduated cylinder. The dichloromethane was transferred to a small beaker then the solid mixture was dissolved in it. A Thin Layer Chromatography (TLC) was conducted with the dissolved mixture in 20% Ethyl Acetate and 80% Hexane solution. The TLC plate was observed to be impure with two spots. To being extraction, a separatory funnel was placed inside of the hood and the stopcock was closed. A flask was placed under the funnel then the mixture was added to the funnel. Next, 10 mL of 3M HCL was measured in a graduated cylinder and

First, dichloromethane was the least polar solvent, so it barely moved up the plate. Hence, the spots on the TLC plate stayed at almost the same place they were spotted on, and separation did not occur. As a result, the retention factor (Rf) values for these components were too small. In addition, the second solvent, methanol, was the most polar solvent out of the three, and the solvent moved up the plate too quickly. This resulted in the components moving up the plate based on the solvent's polarity instead of their own, and a smear of all components at the solvent front was observed. Hence, the Rf values could not be determined. Lastly, ethyl acetate, a moderately polar solvent, moved up the plate with moderate speed. This gave the components time to move up the plate according to their polarity, and the Rf values could be used to identify the unknown compound. According to the TLC method with ethyl acetate solvent, the unknown compound had the same Rf value with acetanilide (Rf = 0.40). As a result, the unknown compound was identified as

In this column chromatography, acetylferrocene was more polar, therefore was held by the silica gel more tightly and moved through the column more slowly when the eluting solvent was nonpolar hexane. Increasing the polarity of the solvent would move all components faster. That explained when the solvent was switched to the more

On a thin chromatography plate, five spots were placed ( as shown in table 2) and the plate was developed using chloroform/methanol. This was later visualized with dragendorff’s reagent under the UV light. All separated components were observed, identified and recorded.

The extraction of the p-tert-butylphenol was then carried out in the exact same fashion as the p-toulic acid, with the exception that the aqueous solution added to the remaining ether solution was 10 mL of 0.5M NaOH. The solution was mixed and the gas was in the funnel, along with the extraction of the aqueous layer three times into a clean and labeled 100-mL beaker. As in the previous step an addition of 5 mL of deionized water was used in the final extraction step. The extracted solution was also saved for later in the experiment as was the ether layer remaining in the separatory funnel.

After wearing the gloves we obtained a chromatography vial from professor and label it with my and my peer initials. We dried up the chromatography vial in fume hood and added 1 ml of chromatography solvent to the vial. Then we took a chromatography strip and measure it 1.5 cm with ruler from one end of the strip and drew a line with pencil we cut two small pieces below the pencil line to form a pointed end. We applied spinach on the strip using quarter to rub the spinach leaf on the line that we drew on the strip and put it into the chromatography vial and placed that in fume hood. We observed as the solvent was moving up the chromatography strip by capillary action. When the solvent was reached approximately 1 cm from the top of the strip then we removed the cap from the vial. We took out the strip from the vial using forceps and marked up the location of the solvent front because it evaporates quickly. We measure out the distance as well as the pigment in order to find out the rf value. Moreover we compared rf values to the one in reference list in order to identify the