In this experiment the only source of Ca2+ ions is Ca(OH)2. Using the experimental Ksp value, calculate the slubility of Ca(OH)2 (in mol/L) in .30 M NaOH.

Experiment Ksp = 1.69x10^-5

1 answer

Ca(OH)2 ==> Ca^2+ + 2OH^-

NaOH ==> Na^+ + OH^-

Ksp = 1.69E-5 = (Ca^2+)(OH^-)^2
Set up an ICE chart.
(Ca^2+) = x
(OH^-) from Ca(OH)2 = x
(OH^-) from NaOH = 0.3
Substitute into Ksp expression to obtain
Ksp = (x)(x+0.3)^2
Solve for x.