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

💡 Solution & Explanation

# Solution: Ions from Potassium Ferrocyanide **Step 1: Write the molecular formula** Potassium ferrocyanide is $K_4[Fe(CN)_6]$ **Step 2: Identify the dissociation in aqueous solution** In water, this complex salt completely dissociates into its ionic components: $$K_4[Fe(CN)_6] \rightarrow 4K^+ + [Fe(CN)_6]^{4-}$$ **Step 3: Determine if further dissociation occurs** The ferrocyanide complex ion $[Fe(CN)_6]^{4-}$ is a **stable coordination complex**. The cyanide ligands are tightly bound to the iron(II) center through strong coordinate bonds, so this complex ion does **not dissociate** into free $CN^-$ ions in aqueous solution. **Step 4: Count total ions** - Potassium ions: **4** - Ferrocyanide complex ions: **1** - **Total ions = 5** **Answer: 5 ions** (Option C) The key point is that while the salt dissociates completely into its ionic constituents, the $[Fe(CN)_6]^{4-}$ complex remains intact due to the strong ligand-field stabilization and high stability constant of this classic complex ion.