Answer:
Option C. Ksp for PbCl₂
Explanation:
The equilibrium constant that is established between a solid and its ions in a saturated solution is what is known as Ksp (solubility product). It is an equilibrium constant based on concentrations.
The concentrations must be equilibrium, that is, concentrations of the ions in a saturated solution. To be sure of such saturation it is convenient to form a precipitate.
The smaller the Kps, the more insoluble the salt