The nickel(ii) ion is commonly dissolved in solution using nickel(ii) nitrate hexahydrate, ni(no3)2.6h2o. the nickel(ii) ion precipitates as ni(oh)2(s) with a ksp value of 6 x 10-16. calculate the molar solubility of nickel(ii) in a solution with a ph of 10.00

Ni(OH)₂ ⇄ Ni⁺² + 2 OH⁻
Ksp = [Ni⁺²][OH⁻]²  = S (2S)² = 4S³
where S is molar solubility.
at pH = 10 
[H⁺] = 10⁻¹⁰
[H⁺][OH⁻] = 10⁻¹⁴ 
so [OH⁻] = 10⁻⁴ M
Ksp = S [10⁻⁴ + 2S]²
Ksp is very small so the molar solubility of OH⁻ will be very small
so (10⁻⁴ + 2S) is about 10⁻⁴
so Ksp = S x 10⁻⁸
S =  = 6 x 10⁻⁸ M