Solution :
Partition coefficient Kd

= 9.0
A). 1 x 200 mL extraction :
Let m be the mass of caffeine in the water
Mass of caffeine in
= 100 - m



m = 10
Mass remaining in coffee = m = 10 mg
B). 2 x 100 mL extraction :
First extraction :
Let
be the mass of caffeine in the water
Mass of caffeine in
=




= 18.18
Mass remaining in coffee =
= 18.18 mg
Second Extraction :
Let
be the mass of caffeine in the water
Mass of caffeine in
=




= 3.3
Mass remaining in coffee =
= 3.3 mg