Chloride ion confirmation test

Steps:

• J contains chloride ions (Cl⁻) and an unidentified cation.
• The cation forms a white hydroxide precipitate that dissolves in aqueous ammonia, indicating Zn²⁺ (Zn(OH)₂ → [Zn(NH₃)₄]²⁺).
• To confirm Cl⁻, add aqueous AgNO₃, which reacts with Cl⁻ to form insoluble AgCl.
• AgCl appears as a white precipitate, verifying Cl⁻ presence.

Why D is correct:

• AgNO₃ + Cl⁻ → AgCl (s) (white precipitate), standard test for chloride ions.

Why the others are wrong:

• A: Cation is Zn²⁺ (white Zn(OH)₂ dissolves in NH₃), not Ag⁺ (brown Ag₂O, insoluble in NH₃).
• B: Incomplete statement provides no testable information.
• C: Ba(NO₃)₂ + Cl⁻ → BaCl₂ (soluble, no precipitate); HNO₃ acidifies but doesn't form BaCl₂ ppt.

Final answer: D