The most soluble compound in water is..

a. CaSO4, ksp = 2,4 x 10^-5
b. CaF2, ksp = 3,9 x 10^-11
c. Ca(OH)2, ksp = 6,5 x 10^-5
d. PbF2, ksp = 3,6 x 10^-8
e. CaCO3, ksp = 4,5x10^-9

answer get 10 point

AxBy ---> xA+ + yB-

Ksp = [A+]^x[B-]^y

In each case, below, let z = cation concentration, [A+]
Calculate z. The one with the highest value is the most soluble.

a. CaSO4 ---> Ca+2 + SO4-2
[Ca+2] = z; [SO4-2-] = z
x = 1; y = 1
Ksp = z^2

b. CaF2 ---> Ca+2 + 2F-
[Ca+2] = z; [F-] = 2z
x = 1; y = 2

c. Ca(OH)2 ---> Ca+2 + 2OH-
[Ca+2] = z; [OH-] = 2z
x = 1; y = 2

d. PbF2 ---> Pb+2 + 2F-
[Pb+2] = z; [F-] = 2z
x = 1; y = 2

e. CaCO3 ---> Ca+2 + CO3-2
[Ca+2] = z; [CO3-2] = z
x = 1; y = 1

Plug these values into the general Ksp equation at the top.