Question

The number of species from the following that are involved in $ sp^3d^2 $ hybridization is $ \text{[Co(NH}_3\text{)}_6\text{]}^{3+}, \text{SF}_6, \text{[CrF}_6\text{]}^{3-}, \text{[CoF}_6\text{]}^{3-}, \text{[Mn(CN)}_6\text{]}^{3-} $ and $ \text{[MnCl}_6\text{]}^{3-} $

• A. 3
• B. 4
• C. 6
• D. 5

Hint:

- Strong field ligands (\( \text{NH}_3 \), \( \text{CN}^- \)) cause inner orbital hybridization (\( d^2sp^3 \)) - Weak field ligands (\( \text{F}^- \), \( \text{Cl}^- \)) promote outer orbital hybridization (\( sp^3d^2 \)) - Non-metal compounds like \( \text{SF}_6 \) always use \( sp^3d^2 \)

Answer 1

The Correct Option is B

Step 1: Identify sp³d² hybridization criteria
- Occurs in octahedral complexes/compounds
- Requires 6 empty orbitals (1 s, 3 p, 2 d)
- Typical for species with either:
- Central atom with 6 bond pairs (e.g., SF₆)
- Transition metal complexes with weak field ligands

Step 2: Analyze each species
- [Co(NH₃)₆]³⁺:
- NH₃ is a strong field ligand → d²sp³ (inner orbital)
- Not sp³d²
- SF₆:
- S uses sp³d² hybridization (6 bond pairs)
- Count = 1
- [CrF₆]^3-:
- F^- is a weak field ligand → sp³d² (outer orbital)
- Count = 1
- [CoF₆]^3-:
- F^- is a weak field ligand → sp³d²
- Count = 1
- [Mn(CN)₆]^3-:
- CN^- is a strong field ligand → d²sp³
- Not sp³d²
- [MnCl₆]^3-:
- Cl^- is a weak field ligand → sp³d²
- Count = 1

Total count: 4 (SF₆, [CrF₆]^3-, [CoF₆]^3-, [MnCl₆]^3-)