Question

In the octahedral crystal field, the correct order of splitting in $C{r}^{3+}$ complexes for $I^{-1},H_{2}O,N{H}_3$ and $C{N}^{-}$is

• A. $C{N}^{-}<N{H}_3<H_{2}O<I^{-}$
• B. $N{H}_3<H_{2}O<I^{-}<C{N}^{-}$
• C. $C{N}^{-}<I^{-}<H_{2}O<N{H}_3$
• D. $I^{-}<H_{2}O<N{H}_3<C{N}^{-}$

Answer 1

Answer: (D)

$\because$ Order of crystal field splitting for the ligands in $C{r}^{3+}$ is
$<\frac{I^{-}<H_{2}O}{\text{ Weak field ligand }}><\frac{N{H}_3<C{N}^{-}}{\text{Strong field ligand }}>$
Hence, correct order is $I^{-}<H_{2}O<N{H}_3<C{N}^{-}$