Other than these errors, this lab provided a lot ofvaluable information.
Some trends were observed – all of the divalent cationsform precipitation with Na3PO4 and Na2CO3and these carbonate and phosphate salts are soluble in nitric acid. All of thetrivalent cations do not form precipitates with 3M HCl while Fe3+forms a yellow complex ion FeCl4-.The trivalent cations also react with NaOH to form precipitates and theprecipitates are soluble in nitric acid.
Also, the divalent cations all reactand form precipitations with 3M NaOH and 3M NH4OH, and thesehydroxide salts are soluble in nitric acid. Ag+ and Pb2+behaves similarly but they can be separated using 3M H2SO4– Pb2+ form a white solid while there was no visible reaction for Ag+.Zn2+ and Mn2+ also have similar behaviors as they reactwith almost every reagent except 3M HCl, 3M H2SO4 and acidicsulfide.
However, Zn2+ forms colorless complex ion Zn(OH)42-when there is an excess amount of OH- ions in the solution, and theprecipitations of Zn2+and Mn2+ have different color so they can be distinguished. Bi3+and Cu2+ will also be hard to separate from each other as they reactwith every reagent except 3M HCl and 3M H2SO4. But Bi3+and Cu2+ can be separated using a 15M NH4OH test becauseCu2+ forms a royal blue Cu(NH3)42+ complexion while Bi3+forms a white Bi(OH)3 precipitate. Overall, the lab was successfulas these trends were observed and most of the observations matched with theappendix.