I know this isn't a physics problem, but it's due tomorrow and I'm really stuck :( Calculate the mass, in grams, of calcium ion dissolved in the water of a 40.0 gallon hot-water tank saturated with calcium phosphate. (Ksp calcium phosphate = 2.0e-29, 1.00gal=3.80L). >> I'm really lost here, we just started Ksp at the end of last class and I'm stuck. So far I just converted 40.0gal = 152L. I also *think* Ksp = [Ca][PO4]? Do I have to set up an equilibrium table? Actually, I'm not even sure of the chemical equation to set up... Ca3(PO4)2 <-> Ca2+ + (PO4)3- ?? :( Please help I'm very confused!!!