Question

Potassium ferrocyanide is an example of _____ complex

• A. tetrahedral
• B. octahedral
• C. square planar
• D. linear

Answer 1

Answer: (B)

octahedral

Answer 2

$K_{4}\left[F e(C N)_{6}\right] \rightleftharpoons 4 K^{+}+\left[F e(C N)_{6}\right]^{4-}$ is $+2$
$F e^{2+}-1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6}, 4 s^{0} 4 p$
Since $CN ^{-}$is a strong field ligand, pairing occurs and the hybridisation of $\left[F e(C N)_{6}\right]^{4-}$ is $d^{2} s p^{3}$ and structure is octahedral.