Test with Chloride Ions user 12 years ago Test with Chloride Ions Out of the 10 cations, only lead(II) ions will form a precipitate with chloride ions.This is because lead(II) chloride is insoluble in water.The chemical reaction is a double decomposition reaction.Pb2+ + 2Cl– → PbCl2Lead(II) chloride will dissolve in hot water.HCl or NaClNa+–Ca2+–Mg2+–Al3+.-Zn2+–Pb2+White precipitate.Dissolve in hot waterFe2+–Fe3+–Cu2+–NH4+–