1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Constant of Solubility

  1. Dec 2, 2013 #1


    User Avatar
    Gold Member

    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.
  2. jcsd
  3. Dec 3, 2013 #2


    User Avatar

    Staff: Mentor

    Your approach is the correct one.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted