In qualitative analysis, Hg22+, Ag+ and Pb2+ are separated from other cations by addition of the HCl. Determine the concentration of Cl- needed to just begin precipitation of AgCl, Hg2Cl2, and PbCl2 in a solution having metal ion concentrations of 0.030 M. Explain what fraction of Pb2+ remains in solution when the Ag+ just begins to precipitate?