How do you find Ksp if you have the molar solubility of the reaction?

Answer 1

Assume you have the salt AxBy and the molar solubility is s.

Then

AxBy <=> xA^(+y) +yB(^-x)
s mole/lt
give... .. .. ..xs .. .. .. ..ys

Ksp=([A(+y)]^x) *[B(-x)]^y =(xs)^x * (ys)^y=>
Ksp= (x^x)*(y^y)*s^(x+y)

e.g. for Fe3(PO4)2 tou have x=3, y=2, so
Ksp=(3^3)*(2^2)*s^(3+2)= 36s^5