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/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3. williamson, kenneth l.; masters, katherine m.. macroscale and microscale organic experiments (available titles coursemate) (page 163). cengage textbook. kindle edition.

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a) 1.5 = (x/100mL) ether / [(30-x)/300] water 
1.5 = 300x / (3000-100x) 
1.5 (3000-100x) = 300x 
4500-150x = 300x 
4500 = 450x 
X= 10 g (1 portion of 100-mL ether) 
portions of 100-mL ether = 10 g x 3 = 30g malononitrile recovered 

b) 1.5 = (x/300mL) ether / [(30-x)/300] water 
1.5 = 300x / (9000 - 300x) 
1.5 (9000 - 300x) = 300x 
13500 -450x = 300x 
13500 = 750x 
X = 18 g 18 g malononitrile recovered
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