Please help me with this question

Question

Describe, step by step, how you would separate the cations (Ag⁺, Ba²⁺, Zn²⁺) from the following mixture by precipitating each ion out of the solution: AgNO_3(aq), Ba(NO₃)_2(aq), Zn(NO₃)_2(aq). 

You can choose the solutions you would use (ie. HCl, H₂SO₄).



Remember to identify the state of each compound as either solid (s) or aqueous (aq).

Answer 1

1) Add HCl(aq) or NaCl(aq) to precipitate out AgCl(s), and filter. (Chlorides are soluble except Ag, Pb, Hg)

2) Add Na₂SO₄(aq) or H₂SO₄ in order to precipitate BaSO₄(s) - need to flocculate before filtering. (sulfates are soluble, except for Ag, Pb, Hg, and the heavy IIAs)

3) Add Ammonium sulfide in order to precipitate ZnS(s) and filter. (Sulfides are insoluble except IA and Ammonium)

If you introduce strong acids or aqueous IA or ammonium compounds they all work. The back end (anion) is what matters.

Take care.