Organic Chem Crystallization of Benzoic Acid and Fluorene Using Hexane and Methanol

Alicia Zahnen

3-10-15

M-W-F Lab 1:25-4:30

Purification and Crystalization of Benzoic Acid and Fluorene using Hexane and Methanol

Intro:

One technique commonly used to purify solid organic substances is called crystallization. The technique involves dissolving a specific solid in a minimal amount of a particular hot solvent creating a saturated solution. The dissolved material has decreased solubility at lower temps and upon allowing it to cool slowly, it will form pure crystals out of the solution. There’s a few things that effect crystallization one needs to pay special attention to while attempting the procedure, boiling points of solvents, solubility, temperature, the polarity of both solutes and solvents and that the solvent is inert and volatile. Extraction, I think, yields a purer product. The difference between extraction and crystallization is that while extraction is difficult in the sense that one must know the reactions occurring as well as what they are looking for within the process, it is much easier in the sense of finding agreeable solvents, and removing impurities within your product. It also has a smaller amount of steps within the procedure. Crystallization is both difficult and frusterating. The steps are more tedious, is easier to make errors, and it is more difficult to find an agreeable solvent to use. One must also know more information within the molecular level and what to expect within the reactions in order to make a successful batch or crystals with impurities removed.

This experiment was about taking benzoic acid and fluorine we had previously isolated through extraction, and learning how to use the technique of crystalization, and comparing the melting points of them both before and after as crystals and see how pure they were after the crystallization process.

Structures:

Physical Data for Reagents.

Compound | Molecular Weight g/mol | Melting Point C | Boiling Point C | Density g/mol |

Fluorene | 166.22 | 113-117 |...