The solubility product of ( Ni ( OH )₂ ) at (298 ~K ) is (2 10⁻¹⁵ ~mol ^3 dm ⁻⁹ ). The ( pH ) value if, its aqueous and saturated solution is

Step-by-step solution

( aligned & Ni ( OH )₂ S ~mol / L Ni ²⁺ + 2 S ~mol / L 2 OH ⁻ & aligned K_ sp = [ Ni ²⁺ ] [ OH ⁻ ]^2 & =S (2 S)^2=4 S^3 & =2 10⁻¹⁵( ~mol / L )^3 aligned aligned ) ( aligned & =2 10⁻¹⁵ ~mol ^3 dm ⁻⁹ S & = ( 2 4 10⁻¹⁵ )^ 1 / 3 8 10⁻⁶ ~mol / L [ OH ⁻ ] & =2 S=2 8 10⁻⁶ ~mol / L pOH & =6- 16=4.983 5 & pH =14- pOH =14-5=9 at 25^ C aligned )