Extraction of Organic Solvent

Extraction is a method used for separating and isolating materials. A compound is pulled from solvent A to solvent B and in this case, both solvents are miscible. These two concepts are not capable of mixing together; when they are mixed together, they form a bilayer. This can be seen when mixing oil and water together. When thinking of extractions, one can picture how coffee gets extracted. The flavors, molecules, caffeine, etc. are extracted from the coffee beans. In this experiment, a solution was extracted containing a known amount of benzoic acid in water with methylene chloride, an organic solvent. The amount of leftover acid was determined through the titration of the aqueous, not the organic, solution with basic NaOH. This allowed the student to calculate and determine the Kd value of both multiple and single extractions. The efficiencies of both single and multiple extractions were observed through this process.

The student began with mixing 50 ml of aqueous benzoic acid with 10 ml of methylene chloride inside a seperatory funnel. The seperatory funnel was shaken for about one to two minutes to allow the two layers to separate. While shaking, it was important for the student to point the stopcock at an angle where venting the funnel would not be a problem. The stem of the funnel was to be pointed away from everyone in case any built-in pressure was not released on time.
After performing these steps, the layers are now separated. The student was able to observe that the organic layer was less dense than water, thus, making it sit at the bottom of the seperatory funnel. The student drained the organic layer into a flask and the aqueous layer was also drained into a labeled Erlenmeyer flask.
Similar too this procedure, to compare the efficiency of multiple extractions, the only difference in the procedure was that

To compare the efficiency of multiple extractions, the same procedure was carried out as the first part with the same amount of