a. The goal of the Extraction lab is to separate and purify benzoic acid, 2-naphthol, and naphthalene. These organic solids are purified by partitioning the solid in 2 immiscible solvents, diethyl ether and sodium bicarbonate or sodium hydroxide. II. Significance
a. The significance of the Extraction lab is to purify Acetanilide benzoic acid, 2-naphthol, and naphthalene by determining the partition coefficient. This value is determined by dividing the solubility of the given solute in the extraction solvent (Sodium bicarbonate or Sodium hydroxide)) by the solubility in the original solvent (Diethyl ether). III. Theory
a. New Techniques
a.i.1. Dissolve 1.082g of benzoic acid, 2-naphthol, and naphthalene mixture in 2mL diethyl ether. Extract the solution with 20mL 1.25M sodium bicarbonate. Shake the conical vial vigorously for 1 minute periodically removing the cap to relieve pressure from the carbon dioxide. The layers separate and the “bicarbonate extract” is removed from the vial. The remaining solution is extracted with 2.5M sodium hydroxide. The same procedure for separating the two solutions is followed for the “hydroxide extract”. The organic solution after the two extractions is removed from the vial and labeled “neutral compound”. Let sit 15 min. a.ii. Precipitating and drying
a.ii.1. After the “hydroxide extract” is cooled, acidify with 3M HCl and cool, a precipitate will form and crystallization will begin. Filter the precipitate with vacuum filtration and follow the recrystallization procedure with water and IPA. Follow these steps with the “bicarbonate extract” but recrystallize with water and ethanol. The organic solution is dried by adding sodium sulfate until the solution becomes clear. After drying the “neutral compound”, remove the solvent using rotary evaporation and weigh the remaining contents to calculate the percent recovery of naphthalene. b. Characterization Method...
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