Question

The generic metal hydroxide M(OH)2 has Ksp = 4.65

Answer 1

part A

M(OH)₂ <------------------> M⁺² + 2OH^-

    S                                      S         2 S

Ksp = [ M⁺²][OH^-]^2

Ksp = (2S)²(S) = 4S³

4.65 x10^-18 = 4S^3

S= solubility = 1.05 x10^-6 M

part B

in presence of common ion salt 0.202M,       M(NO3)2

    here M^+2 = 0.202

Ksp = (0.202) (2S)^2

4.65 x10^-18 = (0.202) (2S)^2

S = solubility = 2.39 x10^-9 M