Analytical Chemistry
posted by Anthony .
Solute S has a partition coefficient of 4.3 between water (phase 1) and hexane (phase 2).
(a) Calculate the concentration of S in hexane if [Swater] is 0.030 M
(b) If the volume of water is 71.0 mL and the volume of hexane is 16.0 mL, find the quotient (mol S in hexane/mol S in water).

It isn't clear to me how your partition coefficient is defined. IF it is
K_{phase 1/phase 2} = 4.3 it is done as follows
4.3 = (in H2O)/(in hexane) = (0.03/x and solve for x.
However, I strongly suspect it is defined as
K_{phase 2/phase 1}. You can move the numbers around accordingly.