Calculate the Ksp of Fe(OH)3  , if the [Fe3+]  is 4.7 x 10^-6 M.

Expert Answers
jeew-m eNotes educator| Certified Educator

`Fe(OH)_3_(s) rarr Fe^(3+)+3OH^-`

 

`Fe^(3+):OH^(-) = 1:3`

 

`[OH^-] = 3[Fe^(3+)`

           `= 3xx4.7xx10^(-6) M`

 

`K_(sp) = [Fe^(3+)][OH^-]^3`

`K_(sp) = (4.7xx10^(-6))(3xx4.7xx10^(-6))^3`

`K_(sp) = 1.3175xx10^-(20)M^4`