Mercury (Hg) is a toxic heavy metal. Typically the "free metal ion", Hg2+, is considered the most toxic form. For a natural water with a pH = 7.8 and containing 0.5 mg Hg/L of total soluble Hg(II) and 50 mg Cl/L of total soluble chloride (Cl-) species, calculate the concentration of all soluble Hg(II) species. Which Hg(II) species is most prevalent? Assume there are no solids present, that the major ligands present are Cl- and OH-, and ignore activity corrections. If you make assumptions to solve this problem, clearly state them and be sure to check them.