Ksp and water solubility.

For the same lead chloride, if one started with solid lead chloride, and poured water over it, then some of the solid would dissolve, so that Ksp=S(2S)2 where S is the solubility (in moles/liter) of lead chloride.

For the same lead chloride, if one started with solid lead chloride, and poured water over it, then some of the solid would dissolve, so that Ksp=S(2S)2 where S is the solubility (in moles/liter) of lead chloride.