Match List I with List II: List I (Complex) List II (Spin-only magnetic moment) (A) [ Fe ( CN )₆ ]³⁻ (I) 0 BM (B) [ CoF ₆ ]³⁻ (II) 1.73 BM (C) [ NiCl ₄ ]²⁻ (III) 2.83 BM (D) [ Pt ( CN )₄ ]²⁻ (IV) 4.90 BM Choose the correct answer from the options given below:

Step-by-step solution

The spin-only magnetic moment is given by = n(n+2) BM, where n is the number of unpaired electrons. (A) [ Fe ( CN )₆ ]³⁻ : Fe(III) is a d⁵ system. Since CN ⁻ is a strong field ligand, it forms a low-spin complex ( t_ 2g ⁵e_ g ⁰ ). Thus, n=1 , and = 1(3) = 1.73 BM. (B) [ CoF ₆ ]³⁻ : Co(III) is a d⁶ system. Since F ⁻ is a weak field ligand, it forms a high-spin complex ( t_ 2g ⁴e_ g ² ). Thus, n=4 , and = 4(6) = 4.90 BM. (C) [ NiCl ₄ ]²⁻ : Ni(II) is a d⁸ system. With the weak field ligand Cl ⁻ and coordination number