Separation of Three Compounds by Extraction free essay sample

Separation of Three Compounds by Extraction Introduction: The purpose of this experiment is do demonstrate the proper procedures of extraction and to develop a practical understanding of this method. In this experiment, extraction is used to separate a known acid, base, and neural compound from each other. The first two compounds undergo proton transfer reactions in the presence of acids or bases. Acids RCOOH, like benzoic acid, was deprotonated to form RCOO-. Bases RNH2, like ethyl 4-aminobenzoate are protonated to form RHN3+. Once the compounds separated into either the aqueous or organic layers, neutralizing the aqueous solution reverses the proton transfer. The major reaction mechanisms are shown below: Results: The results for this experiment are summarized in the data table below. Compound| Real Comp. | Obs. Comp. | Actual Yield| Theoretical Ratio| Obs. Ratio| Obs. m. p. | Physical Appearance| Ethyl 4-aminobenzoate| . 233g| . 2093| 89%| 30%| 20%| 89 Â ° C| Off white appearance; powdery| Benzoic Acid| . 233g| . 243| 104%| 30%| 20%| 125 Â ° C| Clear crystals| 9-fluorenone| . We will write a custom essay sample on Separation of Three Compounds by Extraction or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 11g| . 623| 200%| 40%| 60%| 82 Â ° C| Yellow, filmy,flakes| Discussion: Based on the results, the most accurate extraction achieved was the first compound, ethyl 4-aminobenzoate. With an 89% actual yield of the compound, a 3rd or 4th extraction would acid would have yielded more compound, since several extractions with small amounts is more efficient than one extraction with a larger amount. During the first extraction of benzoic acid with NaOH, it was noticeably hard to distinguish the aqueous and ether layer because both were yellow. Since 9-fluorenone is soluble in both the aqueous and organic solutions, it is possible for some of this compound to be present in the aqueous layer. In the second extraction, however, the two layers were clearly defined, and there was not as much 9-fluorenone in the aqueous layer, due to the fact that the addition of more base to the aqueous layer resulted in a more polarized solution, and the solubility of 9-fluorenone in water decreased. The initial presence of 9-fluorenone in the aqueous layer explains why the observed mass was greater than expected; solid 9-fluorenone was present along with the benzoic acid crystals after the crystals were dried. The weighing scale used could potentially account for the large error in our observed mass of 9-fluorenone. If anything, the observed mass was expected to be less than the real composition, since some of the mass was present with the benzoic acid crystals. The tested melting points for all three compounds correspond with their literature value or range. The accuracy of the measurement for 9-fluorenone might be compromised, since the melting point had to be re-measured with an already heated device, causing 9-fluorenone to melt almost instantly. In the experiment, the most efficient extraction occurred when smaller amounts of the acids and bases were added to the solution multiple times, as demonstrated by our second extraction of benzoic acid contaminated with 9-fluorenone. Due to the molecular geometry of the atoms involved in forming benzoic acid, the compound formed crystals, as expected. Conclusions: In conclusion, the extraction method was used to separate unknown masses of ethyl 4-aminobenzoate, benzoic acid, and 9-fluorenone using strong acids and bases. Through empirical evidence, several extractions with smaller amounts of solvent are more efficient than 1 extraction with larger amounts of solvent.