Question

Among the following anions, identify the anion which gives pale yellow precipitate with aq. AgNO₃. The precipitate is partially soluble in aq. NH₄OH solution.

• A. I^-
• B. Cl^-
• C. Br^-
• D. NO^-₂

Answer 1

The Correct Option is C

To identify which anion gives a pale yellow precipitate with aqueous AgNO₃ that is partially soluble in aqueous NH₄OH, we need to consider the reactions of these anions with silver nitrate and their solubility with ammonium hydroxide.

1. The anion Cl^− when reacted with silver nitrate (AgNO₃) forms silver chloride (AgCl) which is a white precipitate. AgCl is soluble in aqueous NH₄OH, forming a complex ion.
2. The anion Br^− reacts with silver nitrate (AgNO₃) to form silver bromide (AgBr), which is a pale yellow precipitate. AgBr is only partially soluble in aqueous NH₄OH.
3. The anion I^− forms silver iodide (AgI) with AgNO₃, resulting in a yellow precipitate. AgI is insoluble in aqueous NH₄OH.
4. The anion NO_2^− does not form a precipitate with AgNO₃.

Based on the above information:

• Cl^−: Forms a white precipitate, fully soluble in NH₄OH.
• Br^−: Forms a pale yellow precipitate, partially soluble in NH₄OH.
• I^−: Forms a yellow precipitate, insoluble in NH₄OH.
• NO_2^−: No precipitate is formed.

Thus, the correct answer is the anion that produces a pale yellow precipitate with AgNO₃ and is partially soluble in NH₄OH, which is Br^−.