Question

Impure silver ore + CN⁻ + H₂O → [X]⁻ + OH⁻
[X]⁻ + Zn → [Y]²⁺ + Ag (pure)
The co-ordination numbers of the metals in [X], [Y] are respectively:

• A. 3, 4
• B. 1, 4
• C. 2, 4
• D. 2, 2

Hint:

In coordination chemistry, the coordination number of a metal ion refers to the number of ligands attached to it. Common coordination numbers for transition metals are 2, 4, and 6.

Answer 1

The Correct Option is D

In this reaction, impure silver ore reacts with cyanide (CN⁻) and water (H₂O) to form a complex ion [X]⁻. The complex [X]⁻ reacts with zinc (Zn) to form the complex [Y]²⁺ and pure silver (Ag). 
Step 1: The coordination number of the metal in complex [X]⁻, which is silver, is 2. This is because silver typically forms two bonds in its complex ions in the presence of cyanide (CN⁻). 
Step 2: The coordination number of the metal in complex [Y]²⁺, which is zinc, is also 2. Zinc commonly forms two bonds in its coordination compounds, which is confirmed by its interaction with [X]⁻ in the given reaction. 
Step 3: Thus, the coordination numbers of the metals in [X] and [Y] are both 2, making option (4) the correct answer.