The spin only magnetic moment of the complex present in Fehling’s reagent is______ B.M. (Nearest int — d and f Block Elements Chemistry Question

💡 Solution & Explanation

**Step 1: Identify the complex in Fehling's reagent** Fehling's reagent contains the copper(II) complex: [Cu(NH₃)₄]²⁺ **Step 2: Determine the electron configuration of Cu²⁺** Cu²⁺ has the configuration: [Ar] 3d⁹ This means 9 electrons in the d-orbital. **Step 3: Determine the number of unpaired electrons** In the d⁹ configuration, there is **1 unpaired electron** (one electron occupies a d-orbital singly). **Step 4: Apply the spin-only magnetic moment formula** The formula for spin-only magnetic moment is: μ = √[n(n+2)] B.M. where n = number of unpaired electrons **Step 5: Calculate the magnetic moment** With n = 1: μ = √[1(1+2)] μ = √[1 × 3] μ = √3 μ = 1.73 B.M. **Step 6: Round to nearest integer** μ ≈ 2.00 B.M. Therefore, the answer is 2.00.