According to the reaction equation:
PbCrO4 ↔ Pb2+ + CrO42-
so, when the Ksp expression = [Pb2+] [CrO42-]
when the Ksp =2.8 x 10^-13
when the solubility is the amount of solute that dissolved in a unit volume of a solvent so, we can assume solubility = X
by substitution on Ksp expression:
∴2.8 x 10^-13 = X*X
∴X = √(2.8 x 10^-13)
= 5.29 x 10^-7 M
∴ the solubility = X = 5.29 x 10^-7
