Which of the following complex ions is paramagnetic? — Coordination Compounds Chemistry Question

💡 Solution & Explanation

I need to identify which complex ion is paramagnetic. However, you haven't provided the options. Let me show you the **general approach** for determining paramagnetism in complex ions: ## Step-by-Step Method: **1) Identify the metal ion and its d-electron configuration** - Write the electron configuration of the metal center - Account for the oxidation state **2) Determine the ligand field strength** - Strong-field ligands (CN⁻, CO, NO₂⁻) cause large splitting → low spin - Weak-field ligands (H₂O, F⁻, Cl⁻) cause small splitting → high spin **3) Apply crystal field splitting** - For octahedral complexes: electrons fill d-orbitals in $t_{2g}^x e_g^y$ configuration - Strong field: pair electrons first (low spin) - Weak field: maximize unpaired electrons (high spin) **4) Count unpaired electrons** - **Paramagnetic**: ≥1 unpaired electron - **Diamagnetic**: 0 unpaired electrons ## Example Analysis: If option B were $[Fe(CN)_6]^{3-}$: - Fe³⁺: $d^5$ configuration - CN⁻ is strong-field → low spin - Configuration: $t_{2g}^5 e_g^0$ → **1 unpaired electron** → **paramagnetic** ✓ If comparing to $[Fe(CN)_6]^{4-}$ (Fe²⁺, $d^6$): - Strong-field CN⁻ → $t_{2g}^6 e_g^0$ → 0 unpaired electrons → diamagnetic ✗ **Please provide the answer options** and I'll give you the specific solution for option B.