An aqueous solution of compound X gives a positive test for Fe ²⁺ , NH ₄^+ , and SO ₄²⁻ ions. An aqueous solution of compound Y gives a positive test for K ^+ ions but fails to give a positive test for Fe ²⁺ and CN ^- ions. Identify compounds X and Y, respectively.

Step-by-step solution

Compound X dissociates completely in water to give tests for all its constituent ions ( Fe ²⁺ , NH ₄^+ , and SO ₄²⁻ ). This indicates that X is a double salt. Mohr's salt, FeSO ₄ ( NH ₄)₂ SO ₄ 6 H ₂ O , matches these constituent ions. Compound Y gives a test for K ^+ but does not give tests for Fe ²⁺ and CN ^- , meaning the latter two are part of a non-ionizable coordination sphere. This indicates Y is a coordination complex containing potassium as the counter ion and iron(II) and cyanide ligands in the complex ion