When a Group III unknown was treated with an aqueous ammonia/ammonium chloride and ammonium carbonate, a white precipitate was produced. This precipitate dissolved in acetic acid to give a colorless solution. Next, ammonium acetate and potassium chromate were added to a portion of the colorless solution and no precipitate was observed, Addition of ammonium oxalate to the remainder of the solution produced a white precipitate. Indicate for each ion in Group III whether it was definitely present, definitely absent, or that you cannot decide from the given information.