A solution may contain the following ions Ag+, Cu^2+, Mn^2+, Ca^2+, and Na+. No precipitate formed when 0.10 M NaCl was added but a dark colored precipitate formed when H2S was added to an acidic portion of the solution. After the removal of the solid the solution was made basic and more H2S was added and a dark precipitate again formed. Treatment of the filtrate with (NH4)2CO3 resulted in a white precipitate. If no further test were made then what conclusions can you draw?