5. The distribution constant (partitioning coefficient) for X between n-hexane and water is 8.9. Calculate the concentration of X remaining in the aqueous phase after 50.0 mL of 0.200 M X is treated by extraction with the following quantities of n-hexane: (a) one 40.0-mL portion. (b) two 20.0-mL portions. (c) four 10.0-mL portions. (d) eight 5.00-mL portions.