Question

Lab Section: 1 Prelab: Inorganic Group I Ions 1. On the report sheet, complete the flow diagram for the separation and identification of the ions in Group I 2. Write balanced net ionic equations for the following reactions: The precipitation of the chloride of Pb a. in Step 1. The formation of a yellow precipitate in Step 4. b. The formation of a complex ion in Step 5. c. d. The reaction that forms a white precipitate in Step 5. 3. A solution may contain Ag', Pb, and Ba. A white precipitate forms on addition of 6 M HCI, and is separated from the solution. When 1 M sodium sulfate is added to this first solution, no precipitate forms. The precipitate from the HCl addition is partially soluble in hot water; the residue dissolves on addition of 6 M NH. Which of the ions are present and which are absent? State your reasoning. (In "paper" unknowns such as this one, confirmatory tests are often omitted. The partial solubility of the precipitate in hot water implies that one of the ions is present, and so we report it present.) Present Absent

Answer 1

separation of Group-1 Group-1 contain Ag+, Pb2t Batt Pbat cap.) +zu (ap) PbCl₂ (8) White ppt. b) PbCl2 (8) hot water pbla (21) Reaction with KI as follow Net reaction: Pb²+ (aq) +21 (al.) Pb Iz (B) Yellow

c. I Ag418) + 2NH3 (21) — [Ag (NH3),]fcal) + [Ag (NH3)2] (ap.) + 2 H₂ot (ap.) + ce-lap) "lop.) Agce (8) + 2NH4Cap+242010)