4 The distributiou coefficients for a compound X are as foll

4. The distributiou coefficients for a compound X, are as follows: Keyelobexauelwater = 1 .5 Kaliedhyl elieriwater 5.1 enlabe/waler If 100mg of X is in 50 m of water, underline the besf solvent and circle the nworst solvent to use in extracting compound X. cyclohexane, pentane, diethyl ether. Using the distribution coefficient, K, values for the best and the worst solvent, show how much is extracted when 50 mL organic solvent. Show work A. Calculate the amount extracted with the best solvent B. Calculate the amount extracted with the worst solvent

Solution

When a solute that is soluble in two immiscible liquids, the solute distributes itself between the two liquids in such a way that the ratio of its concentration in the two liquid phases is a constant known as the partition coefficient.

Among the given combinations K _{pentane/water} is highest i.e. 11.2. Therefore, pentane will be the best solvent. and cyclohexane will be the worst solvent.

A. if 100 mg of X is in 50 ml water, by extracting with 50 ml of pentane, the ratio of X in pentane and water will be 11.2.

i.e. 8.19 mg will be in water and rest of 41.81 mg will be in pentane.

B. if cyclohexane is used as a solvent for extraction, then the ratio of X in cyclohexane and water will be 1.5.

i.e. 20 mg will be in water and 30 mg in cyclohexane solvent.