Select incorrect sequence of solubility product values among the following

Options

A. `CoS gt CuS`
B. `NiS gt PbS`
C. `Fe(OH)_(3) gt Fe(OH)_(2)`
D. `Ni (OH)_(2) gt Cr(OH)_(3)`

Answer

C

Explanation

`Fe(OH)_(3) to underset (x) (Fe^(3+)) + underset (3x)(3OH^(-))`
`K_(sp) = x xx (3x)^(3)`
`Fe(OH)_(2) = underset (x) (Fe^(2+)) + underset (2x)(2OH^(-))`
`K_(sp) = x xx (2x)^(2)`
`= 4x^(3)`