Question

The Ksp of aluminum hydroxide is 5 x 10 -33.At what ph foes Al(OH)3 just begin to precipitate in a 0.15M solution of AlCl3?

Answer 1

Al(OH)3 ==> Al^+3 + 3OH^-

Ksp = (Al^+3)(OH^-)^3
Plub in Ksp and Al^+ from the problem, solve for OH^-