Suppose a reaction mixture, when diluted with water, afforded 300 mL of an aqueous solution of 30 g of the reaction product malononitrile [CH2(CN)2], which is to be isolated by extraction with ether. The solubility of malononitrile in ether at room temperature is 20.0 g/100 mL, and in water is 13.3 g/100mL. The ratio of these quantities is equal to the partition coefficient, k, which equals 1.5. What percent of malononitrile would be recovered by extraction of (a) three successive 100-mL portions of ether and (b) one 300-mL portion of ether? SHOW WORK. Suggestion: For each extraction, let x equal the weight extracted into the ether layer.
Side note: In part (a), for the first of the three extractions, the concentration of malononitrile in the ether layer is x/100 and in the water layer is (30-x)/300. Note in the 2nd of the 3 100-mL extraction the grams of malononitrile is no longer 30.