Question

Transition metal complex with highest value of crystal field splitting $\left(\Delta_{0}\right)$ will be

• A. $\left[ Cr \left( H _{2} O \right)_{6}\right]^{3+}$
• B. $\left[ Mo \left( H _{2} O \right)_{6}\right]^{3+}$
• C. $\left[ Fe \left( H _{2} O \right)_{6}\right]^{3+}$
• D. $\left[\operatorname{Os}\left( H _{2} O \right)_{6}\right]^{3+}$

Answer 1

Answer: (D)

CFSE of octahedral complexes with water is greater for $5d$ series metal centre ion as compared to $3d$ and $4d$ series metal centre.