The metal ions that have the calculated spin only magnetic moment value of 4.9 B.M. are A. Cr ²⁺ B. Fe ²⁺ C. Fe ³⁺ D. Co ²⁺ E. Mn ³⁺ Choose the correct answer from the options given below

Step-by-step solution

Given magnetic moment =4.9 B.M. We know M.M = n ( n +2) B.M. Where, n No. of unpaired e ⁻ 4.9= n ( n +2) We get n =4 (A) ₂₄ Cr ²⁺ [ Ar ] 3 ~d ^4 (4 unpaired e) (B) ₂₆ Fe ²⁺ [ Ar ] 3 ~d ^6 (4 unpaired e) (C) ₂₆ Fe ³⁺ [ Ar ] 3 ~d ^5 (5 unpaired e) (D) ₂₇ Co ²⁺ [ Ar ] 3 ~d ^7 (3 unpaired e ⁻ ) (E) ₂₅ Mn ³⁺ [ Ar ] 3 ~d ^4 (4 . unpaired . e ⁻ )