NEETChemistryCoordination Compounds
Which of the following statements correctly describes the hybridization and magnetic nature of the complexes [ Fe ( CN )₆ ]⁴⁻ and [ Fe ( H ₂ O )₆ ]²⁺ ?
Options
- A[ Fe ( CN )₆ ]⁴⁻ is d ^2 sp ^3 hybridized and diamagnetic, while [ Fe ( H ₂ O )₆ ]²⁺ is sp ^3 d ^2 hybridized
- B[ Fe ( CN )₆ ]⁴⁻ is sp ^3 d ^2 hybridized and paramagnetic, while [ Fe ( H ₂ O )₆ ]²⁺ is d ^2 sp ^3 hybridized
- C[ Fe ( CN )₆ ]⁴⁻ is d ^2 sp ^3 hybridized and paramagnetic, while [ Fe ( H ₂ O )₆ ]²⁺ is sp ^3 d ^2 hybridized
- D[ Fe ( CN )₆ ]⁴⁻ is d ^2 sp ^3 hybridized and diamagnetic, while [ Fe ( H ₂ O )₆ ]²⁺ is sp ^3 d ^2 hybridized
Correct answer
A. [ Fe ( CN )₆ ]⁴⁻ is d ^2 sp ^3 hybridized and diamagnetic, while [ Fe ( H ₂ O )₆ ]²⁺ is sp ^3 d ^2 hybridized
Step-by-step solution
In both [ Fe ( CN )₆ ]⁴⁻ and [ Fe ( H ₂ O )₆ ]²⁺ , the central metal ion is Fe ²⁺ which has a 3 d ^6 electronic configuration. In [ Fe ( CN )₆ ]⁴⁻ , CN ⁻ is a strong field ligand. It causes pairing of the 3 d electrons against Hund's rule, leaving no unpaired electrons. Therefore, it utilizes two inner 3 d orbitals to undergo d ^2 sp ^3 hybridization (forming an inner orbital complex) and is diamagnetic. In [ Fe ( H ₂ O )₆ ]²⁺ , H ₂ O is a weak field ligand. It does not cause pairing of the 3 d electrons, leaving 4