What is the minimum pH at which aluminum hydroxide,
Al(OH)3 will precipitate from a 0.020 M Al(NO3)3 solution. Consider activity effects.
The Ksp for Al(OH)3 is 3x10^(-34).
Assume the pH can be changed without increasing the solution volume.
Al(OH)3 = (Al+++) + 3(OH-)
Ksp of Al(OH)3 = 3*10^(-34) < [Al+++]*[OH-] => for ...
The solution explains, through calculations, how to determine the minimum pH for precipitate formation.