Liquid-Liquid Extraction Sample Essay

The success of pull outing each compound out of the solution can be seen in the IR graphs for each substance. For ethyl 4-aminobenzoate. the N-H. C=O and C-O are distinguishable in their proper wavenumber places. The aminic N-H stretch was found between 3224 cm-1 and 3423 cm-1. The C=O was found at 1681 cm-1 and the C-O was at 1280 cm-1. The IR for benzoic acid besides displays its important bonds. O-H and C=O. The O-H was between 2566 and 3222 cm-1 and the C=O stretch was found at 1685 cm-1. The IR for 9-fluorenone did non demo any important bonds except for at 1681 cm-1. the C=O stretch.

To divide 4-aminobenzoate into an aqueous bed. HCl was added to protonate the NH2 side group and organize a salt. making its high solubility in H2O and low solubility in quintessence. This allowed the non-miscible beds to be distinguished. The add-on of NaOH after pouring out the aqueous solution allowed for aminobenzoate to reform from its salt signifier. However. while inverting the funnel to blowhole before pouring out the bed. some solution leaked out of the cap. which may account for the loss of wholly retrieving this compound because merely 39. 3 % of ethyl 4-aminobenzoate was recovered.

For the recovery of benzoic acid. NaOH was added to change over the carboxylic acid of the benzine to the water-soluble benzoate anion. which dissolves in the aqueous NaOH solution while the non-acidic drosss remain in the organic stage. After dividing the aqueous bed into an Erlenmeyer flask. the basic solution of Na benzoate was acidified by rinsing it with HCl and filtrating it with DI H2O. This compound had to most important recovery of 46. 3 % . but some may hold been lost through the escape of the old extraction.

The impersonal compound left in the organic bed was the most hard to pull out. It’s IR graph does non properly demo a pure substance. but many mistakes were involved in its extraction. Since this was the last staying compound in the organic bed. an anhydrous drying agent. Na2SO4. was used to adhere to H2O and take it from the organic liquid. Not much of the organic bed was left over. but more and more of the drying agent had to be added because the solution kept organizing bunchs. so a big sum of H2O must hold been present. More organic dissolver should hold been added besides. but at the clip. it was non. so some merchandise may hold been lost by its soaking up on the drying agent. After 10 proceedingss. the drying agent was washed. and the ether solution was transferred to a new flask to be recrystallized on a hot home base. Recrystallization involves fade outing an impure solid in a hot dissolver and destructing the impure crystal lattice. so returning it to a solid by precipitating in a cool dissolver and bring forthing a purer crystal lattice.

However. bonds appear in the O-H part of the IR graph and show that this compound was still impure. This may hold happened because the solution should hold been dried longer with the drying agent. or the recrystallization happened excessively fast because it was at a hot temperature. Slow chilling is supposed to advance the formation of pure crystals because the molecules of the drosss. that do non suit good into the freshly forming crystal lattice. have clip to return to the solution. However. the rapid crystal formation must hold trapped the drosss because the lattice grew so rapidly that the drosss were surrounded by the crystallising solute. This is why 9-fluorenone seemed impure and how excessively much drying agent and escape during filtration may hold contributed to its 27 % recovery.