What pH buffer solution is needed to give a Ni2+ concentration of 2.5 x 10-3M in equilibrium with solid nickel hydroxide Ni(OH)2? Ksp = 6.0 x 10-16.

Answer 1

Ksp = (Ni^2+)(OH^-)^2
Substitute Ni from the problem into the Ksp expression and solve for Oh^-, then convert this to pH.