Calculate the solubility (S) of Al(OH)3 based on [OH-] concentration (mol/L)?
Suppose the concentration of [OH-] is obvious and can be adjusted by the experimenter. Also, calculate the minimum molar solubility?
KdAl(OH)4-/Al3+=1.2x10-34 Ksp Al(OH)3=5x10-33
It's always better to give numbers instead of generalities. Say you know (OH)^- = 0.01 M, calculate solubility, S, of Al(OH)3. Then
.............Al(OH)3 ==> Al^3+ + 3OH^-
I.............solid..............0................0
C............solid..............S................3S
E.............solid..............S................3S
Ksp = (Al^3+)(OH)^3 = 5E-33
5E-33 = (S)(3S)^3
But you know (OH) = 3S = 0.01 M so
5E-33 = (S)(0.01)^3 = and solve for = solubility in moles/L.