Hey there!:
Kd for "A" = C (ligroin) / C (water) = 8.0
6 gm A in 50 mL water using 50 mL ligorin in single extraction.
Let x g of A is extracted.
Kd = (x / 50 mL ligorin) / ((6 - x) / 50 mL water)
8.0 = x / (6 - x)
48 - 8*x = x
9*x = 48
x = 48 / 9
x = 5.33 g
Hope that helps!
