larutan jenuh M(OH)2 mempunyai PH=9 , maka tetapan hasil kelarutan adalah

M(OH)^2 --> M2+ + 2OH-
S. S. 2S
PH = 9 --> POH = 5
[OH-] = 10^-5
2S = 10^-5
S = 5.10^-6
Ksp = [M2+] [OH-]^2
= S (2S)^2
= 4S^3
= 4 ( 5. 10^-6)^3
= 4 x 125 x 10^-18
= 5 x 10^-16