Complete the ICE table below to show the solubility of iron

Complete the ICE table below to show the solubility of iron (11) hydroxide in 0.100 M Fe(NO,)2. Then calculate the molar solubility 17 (ans. 1.10x 10\" M)

Solution

Fe(NO3)2 (aq) -------------------> Fe^2+ (aq) + 2NO3^- (aq)

                                                  0.1M

        Fe(OH)2 (s) ------------------> Fe^2+ (aq) + 2OH^-

I                                                      s                    2s

C                                                    +0.1            2s

E                                                   s+0.1             2s

     Ksp    = [Fe^+][OH^-]^2

4.87*10^-17   = (s+0.1)(2s)^2                                 [ s+0.1 = 0.1]

4.87*10^-17    = 0.1*4s^2

s^2               = 4.87*10^-17/0.4

s^2              = 1.2175*10^-16

s                  = 1.1*10^-8 M

The solubility   = 1.1*10^-8M