Fluorene Chromatography

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

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

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