Question

In which of the following complex ion, the central metal ion is in a state of $s{p}^3{d}^2$ hybridisation ?

• A. $[Co{F}_6]3^{3-}$
• B. $[Co(N{H}_3{)}_6{]}^{3+}$
• C. $[Fe(CN{)}_6{]}^{3-}$
• D. $[Cr(N{H}_3{)}_6{]}^{3+}$

Answer 1

Answer: (A)

Electronic configuration of $C{o}^{2+}$ ion



$F^{-}$ is a weak ligand. It cannot pair up electrons with $d$ -subshell and forms outer orbital octahedral complex. ${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}$ ion



${\left[Fe(CN{)}_6\right]}^{-3}$ ion



${\left[Cr{\left(N{H}_3\right)}_6\right]}^{3+}$ ion



$N{H}_3$ and $C{N}^{-}$ are strong ligands. So, they form inner orbital complex.