The number of ions formed from a molecule of potassium ferrocyanide in aqueous solution is — Coordination Compounds Chemistry Question

💡 Solution & Explanation

# Potassium Ferrocyanide Ionization **Step 1: Identify the compound** Potassium ferrocyanide is $K_4[Fe(CN)_6]$ — a coordination complex containing 4 potassium ions and one ferrocyanide complex ion. **Step 2: Dissociation in aqueous solution** When dissolved in water, it completely ionizes: $$K_4[Fe(CN)_6] \rightarrow 4K^+ + [Fe(CN)_6]^{4-}$$ **Step 3: Count the ions formed** - 4 potassium ions: $K^+$ - 1 complex ion: $[Fe(CN)_6]^{4-}$ (remains intact — the CN⁻ ligands do **not** dissociate from the iron center in aqueous solution) **Result:** Total ions = 4 + 1 = **5 ions** The ferrocyanide complex ion $[Fe(CN)_6]^{4-}$ is highly stable and does not dissociate further in dilute aqueous solutions, so the cyanide ligands remain coordinated to iron. **Answer: C (5 ions)**