In this experiment, nitration was used show electrophilic aromatic substitution of bromobenzene. To achieve this, the nitration of bromobenzene was performed, followed by thin layer chromatography and column chromatography. For the nitration, 4.01 mL of nitric acid, 4.00 mL of sulfuric acid, and 4.56 mL bromobenzene were used to complete the reaction. With these measurements, bromobenzene was found to be the limiting reagent. Since only 4.56 mL of bromobenzene was used, the amount of product predicted to be recovered was 8.7533 g. This was a combined weight of all of the products, with p-bromonitrobenzene contributing the most to the amount recovered. This was shown in the % recoveries found for all of the compounds. Overall, the amount of
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This was then multiplied by 100 to get an overall percentage of total products recovered. The p-bromonitrobenzene powder was 65.24 % of the 59.57 % of product that was recovered. This was the greatest contributor to the overall amount recovered. This fact is represented in the physical amount of this compound, which is much more than any of the other recovered products. The second largest contributed was the ortho-para mixture isolated from column chromatography. This was 28.07% of the 56.57 % recovered. Next was the p-bromonitrobenzene with 6.29 %, and finally o-bromonitrobenzene with 0.39%. Even though, the pure compounds isolated from column chromatography resulted in a low yield, both compounds were analyzed by spectroscopic means and their identities were …show more content…
After the nitration, the mother liquor and the white powder recovered were analyzed. This resulted in a TLC plate containing 3 spots, one for the white powder and two for the mother liquor. By the comparison of the two compounds, two products were present. The powder consisted of p-bromonitrobenzene, while the mother liquor contained bot ortho and para products. This is seen in the Rf values of the compounds. Both compounds contain an Rf value of about 0.59. This represents the para product because the para product is not trapped by the silica therefore resulting in a larger value than the second Rf value seen in the mother liquor compound. This value was 0.48, which was significantly lower than the other two. This Rf value represents o-bromonitrobenzene. This TLC also indicated that there was no multi-substituted bromobenzene recovered. A multi-substituted bromobenzene would have resulted in another spot lower to the origin in the mother liquor. Overall, the TLC confirmed that the reaction stopped at the correct stopping point for this experiment, and gave an initial confirmation of the products identity. TLC was also used to monitor column
This was then multiplied by 100 to get an overall percentage of total products recovered. The p-bromonitrobenzene powder was 65.24 % of the 59.57 % of product that was recovered. This was the greatest contributor to the overall amount recovered. This fact is represented in the physical amount of this compound, which is much more than any of the other recovered products. The second largest contributed was the ortho-para mixture isolated from column chromatography. This was 28.07% of the 56.57 % recovered. Next was the p-bromonitrobenzene with 6.29 %, and finally o-bromonitrobenzene with 0.39%. Even though, the pure compounds isolated from column chromatography resulted in a low yield, both compounds were analyzed by spectroscopic means and their identities were …show more content…
After the nitration, the mother liquor and the white powder recovered were analyzed. This resulted in a TLC plate containing 3 spots, one for the white powder and two for the mother liquor. By the comparison of the two compounds, two products were present. The powder consisted of p-bromonitrobenzene, while the mother liquor contained bot ortho and para products. This is seen in the Rf values of the compounds. Both compounds contain an Rf value of about 0.59. This represents the para product because the para product is not trapped by the silica therefore resulting in a larger value than the second Rf value seen in the mother liquor compound. This value was 0.48, which was significantly lower than the other two. This Rf value represents o-bromonitrobenzene. This TLC also indicated that there was no multi-substituted bromobenzene recovered. A multi-substituted bromobenzene would have resulted in another spot lower to the origin in the mother liquor. Overall, the TLC confirmed that the reaction stopped at the correct stopping point for this experiment, and gave an initial confirmation of the products identity. TLC was also used to monitor column