Final answer:
The correct equation for the Ksp of Ca(OH)2, where x is the molar solubility, is Ksp = [Ca2+][OH-]^2 = x(2x)^2 = 4x^3. You would solve for x by setting the Ksp value for Ca(OH)2 equal to 4x^3.
Step-by-step explanation:
If x represents the molar solubility of Ca(OH)2, the correct equation for the solubility product constant, Ksp, is obtained by considering the dissolution of Ca(OH)2 and the concentrations of the ions at equilibrium. Ca(OH)2 dissociates into Ca2+ and OH- ions as follows:
Ca(OH)2(s) → Ca2+(aq) + 2OH-(aq)
At equilibrium, the concentrations of the ions will be [Ca2+] = x and [OH-] = 2x because for every mole of Ca(OH)2 that dissolves, one mole of Ca2+ ions and two moles of OH- ions are produced. The solubility product expression is then:
Ksp = [Ca2+][OH-]2 = x(2x)2 = 4x^3
To find the molar solubility, you would set the Ksp value for Ca(OH)2 equal to 4x^3 and solve for x.