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: Identify the compound formula** Potassium ferrocyanide is $K_4[Fe(CN)_6]$ **Step 2: Dissociation in aqueous solution** In water, this complex salt completely dissociates: $$K_4[Fe(CN)_6] \rightarrow 4K^+ + [Fe(CN)_6]^{4-}$$ **Step 3: Check if the complex ion further dissociates** The ferrocyanide complex ion $[Fe(CN)_6]^{4-}$ is highly stable. In dilute aqueous solution, it does **not dissociate** into $Fe^{2+}$ and $CN^-$ ions because: - The ligand field strength of CN⁻ is very high - The complex has exceptional stability **Step 4: Count total ions** From one molecule of $K_4[Fe(CN)_6]$: - 4 potassium ions: $K^+$ - 1 ferrocyanide complex ion: $[Fe(CN)_6]^{4-}$ **Total ions = 5** The answer is **C (5 ions)**.