Above what Fe2+ concentration will Fe(OH)2 precipitate from a buffer solution that has a pH of 8.74 ?

Question

The 𝐾sp of Fe(OH)2 is 4.87×10−17.

Answer 1

....................Fe(OH)2 ==> Fe^2+ + 2OH^-
Ksp = (Fe^2+)(OH^-)^2 = 4.87E-17
Convert pH = 8.74 to pOH and to (OH^-). Plug OH^- into the Ksp expression and solve for (Fe^2+). Post your work if you get stuck.