A 2 x 10^-3 M solution of MnSO4 is gradually made more basic by adding NaOH. At what pH will manganese(II) hydroxide begin to precipitate? [Ksp of Mn(OH)2=2 x 10^-13]

Answer 1

Mn(OH)2 ==> Mn^+2 + 2OH^-
Ksp = (Mn^+2)(OH^-)^2
You know Ksp and Mn, calculate OH^- and from there pOH, then pH. Post your work if you get stuck.