Question

In which of the following pair the EAN of central metal atom is not same ?

• A. $[Fe(CN{)}_6{]}^{3-}$ and $[Fe(CN{)}_6{]}^{4-}$
• B. $[Cr(N{H}_3{)}_6{]}^{3+}$ and $[Cr(CN{)}_6{]}^{3-}$
• C. $[Fe{F}_6{]}^{3-}$ and $[Fe(CN{)}_6{]}^{3-}$
• D. $[Ni(CO{)}_4]$ and $[Ni(CN{)}_4{]}^{2-}$

Answer 1

Answer: (D)

$EAN=Z-X+Y$
$Z=$ Atomic number of the metal
$X=$ Number of electrons lost during the formation of the metal ion from its atom
$Y=$ Number of electrons donated by the ligands
For $\left[Ni(CO{)}_4\right]$
$EAN=Z-X+Y=28-0+8=36$
For ${\left[Ni(CN{)}_4\right]}^{2-}=28-2+8=34$
Thus the EAN of $\left[Ni(CO{)}_4\right]$ and ${\left[Ni(CN{)}_4\right]}^{2-}$ is not the same.