Suppose you need to extract an organic substance S from water into ether, where the distribution constant Kdist = [S]org/[S]aq is at first unknown.
a) By testing the solubility of the material in each solvent under saturating conditions at room temperature, you find that it has a solubility in water of 12 g L–1 but it is 36 g L–1 in ether. What is the value of Kdist for this solvent pair? Hint: Assume you start with 48 g.
b. If you use equal volumes of water and ether in your extraction, what percentage of the material will be transferred to the ether phase? Hint: Suppose you have 48 g of substance and use 1 L of each solvent, then use the solubilities in each phase and the Kdist value from part (a).
(c) What is the minimum volume of water required to dissolve 7.2 g of your substance?
d.Suppose now that you have a saturated solution in water. If you then extract this with one sixth the volume of ether as you have water, what percentage of the material will find itself in the ether phase? Hint: The Kdist value will still apply.