1. The problem statement, all variables and given/known data A saturated solution of iron(II) hydroxide has a molar solubility of 3.65 x 10^-6 M. Calculate the Ksp for Fe(OH)2. 2. Relevant equations Ksp = [A]^a^b 3. The attempt at a solution Fe(OH)2 --> Fe^2+ + 2OH- Ksp = [3.65 x 10^-6 M] * (2*[3.65 x 10^-6 M])^2 This, however, doesn't yield an answer. The professor's answer is equivalent to [3.65 x 10^-6 M] * ([3.65 x 10^-6 M])^2 I'm assuming this is an error on his part because the concentration of hydroxide ions should be twice the concentration of iron ions, not the same.