problem about partition coefficient

solvent 1 and solvent 2 are two immiscible solvents( 2 solvents do not dissolve each other), usually one organic solvent e.g. ether, one aqueous solvent
e.g. water

the solute will dissolve in both solvents, at different extent

which is the upper layer is not important, because usually u express the
partition coefficient between solvent 1 and solvent 2 =
{solute} solvent 1
-------------------
{solute} solvent 2


partition coefficient can be smaller than 1

Partition coefficient = [Solute in solvent 1] / [Solute in solvent 2]

通常題目會指出哪個 solvent 是 solvent 1。若題目未指出哪個是 solvent 1，你自已可以定義便可以了。