Question

The complex with highest magnitude of crystal field splitting energy (Δ0) is

• A. \([Ti(OH)_2)_6]^{3+}\)
• B. \([C_r(OH)_2)_6]^{3+}\)
• C. \([m_n(OH)_2)_6]^{3+}\)
• D. \([F_e(OH)_2)_6]^{3+}\)

Answer 1

The Correct Option is B

Key Observations: 

• \( \Delta_0 \) depends on:
  • The charge of the metal ion — higher charge increases \( \Delta_0 \).
  • The size of the metal ion — smaller size increases \( \Delta_0 \) due to stronger ligand interactions.
• [Cr(H₂O)₆]³⁺:
  • Chromium has a +3 charge, which is relatively high.
  • The small ionic radius of Cr³⁺ allows for stronger interactions with the ligands.
  • This results in the highest crystal field splitting energy (\( \Delta_0 \)) among similar complexes.

Conclusion:

[Cr(H₂O)₆]³⁺ has the highest \( \Delta_0 \) due to its high positive charge and small ionic radius, leading to stronger ligand interactions.