I am a bit confused re. solubility calculations.
Calculate the solubility of Pb(OH)2 at pH 10. Setting up the expression for Ksp:
Ksp = [Pb2+][OH-]2 = 8* 10^-17 (Ksp value from SI chemical data)
pOH = 14 - 10 = 4, i.e. [OH-] = 10-4.
8*10-17 = [Pb2+][OH-]2. Solving for [Pb2+] we get that [Pb2+] = 8*10-9.
My question is: why couldn't we use the relationship between the concentrations of Pb2+ and OH- like we do with ICE tables, to get the result? I mean, couldn't we just divide the concentration of OH- by 2 and get the concentration of Pb2+..?