Fluorene Isolation Lab Report

The main objective of this experiment was to isolate the compounds in a given mixture, which was composed of 50% fluorene, 40% o-toluic acid, and 10% 1, 4-dibromobenzene. Techniques of extraction and crystallization was used to perform the separation. The experiment was separated into two parts; each part was to isolate a major compound from one another. The two major compounds (fluorene and o-toluic acid) were also collected. The o-toluic acid was extracted first by using macroscale extraction and by testing for acidity. By adding a strong acid to the aqueous layer, which contained the 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 layer

The percent recovery of the acid was 42%, but there was originally 40% of o-toluic acid in the mixture. The extra 2% could have been the impurity, 1, 4-dibromobenzene, which was isolated in the next part of the experiment. There is also another possible reason on why more acid was recovered. The acid wasn’t dried completely before it was weighed; the clumpy solids of the acid prove that it was still wet and thus, the extra liquid added to its mass. This could have been prevented by allowing the acid to dry longer or by drying it in an oven. Since the volatility of o-toluic acid is almost the same as water, it takes longer for the compound to dry at room temperature. Nevertheless, the procedure for removing the acid was performed successfully. The melting point for o-toluic acid was discovered to be 99.2° – 101.1° C, which is lower than the literature melting point of 102°-104° C. However, there is not a huge discrepancy and obtained substances usually have lower melting points than the stated literature melting