Question

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

• A. $CN ^{-}< NH _{3}< H _{2} O < I ^{-}$
• B. $NH _{3}< H _{2} O < I ^{-}< CN ^{-}$
• C. $CN ^{-}< I ^{-}< H _{2} O < NH _{3}$
• D. $I ^{-}< H _{2} O < NH _{3}< CN ^{-}$

Answer 1

Answer: (D)

$\because$ Order of crystal field splitting for the ligands in $Cr ^{3+}$ is
$< \frac{ I ^{-}< H _{2} O }{\text { Weak field ligand }} >< \frac{ NH _{3}< CN ^{-}}{\text {Strong field ligand }}>$
Hence, correct order is $I ^{-}< H _{2} O < NH _{3}< CN ^{-}$