Question

The most stable ion is :

• A. ${\left[Fe(OH{)}_5\right]}^{3-}$
• B. ${\left[FeC{l}_6\right]}^{3-}$
• C. ${\left[Fe(CN{)}_6\right]}^{3-}$
• D. ${\left[Fe{\left(H_{2}O\right)}_6\right]}^{3+}$

Answer 1

Answer: (C)

Stability of complex increases with increase in charge on the central metal ion increase with basic strength of ligand. $In{\left[Fe(CN{)}_6\right]}^{3-}$
oxidation state of Fe is +3 and basicity of $C{N}^{-}$ is higher than $O{H}^{-},C{l}^{-}$ and $H_{2}O$.