Boiling and adding lime are two of the older methods used to soften water containing temporary hardness. Permanent hardness is simply the hardness that is not removed by boiling. Find the solubility products for calcium sulfate and calcium carbonate and use them to justify that calcium sulfate is much harder to remove upon boiling the water. What can you say about the thermodynamics of Ksp? Justify how adding lime you can remove the temporary hardness