Question

In the metal carbonyls of the general formula $M{\left(CO\right)}_x$ where M = metal, x = 4, EAN rule satisfied for atomic number of M equal to :

• A. 25
• B. 26
• C. 27
• D. 28

Answer 1

The correct option is D 28

EAN rule:-

The total number of $e^{-}s$ linked with the central metal atom or ion in a complex plus the $e^{-}s$ donated by the ligand is known as Effective Atomic Number, i.e; $EAN$. It is the attainment of noble gas configuration.

$EAN=Z-x+2nL$

$Z$= atomic number of the metal in the complex ion.

$x$= oxidation state of the central metal atom.

$n$= no. of ligands.

$L$= no. of coordinate bond formed by the ligand.

EAN rule:-

The total number of $e^{-}s$ linked with the central metal atom or ion in a complex plus the $e^{-}s$ donated by the ligand is known as Effective Atomic Number, i.e; $EAN$. It is the attainment of noble gas configuration.

$EAN=Z-x+2nL$

$Z$= atomic number of the metal in the complex ion.

$x$= oxidation state of the central metal atom.

$n$= no. of ligands.

$L$= no. of coordinate bond formed by the ligand.

$M(CO{)}_4$

EAN$\Rightarrow 36=z-0+2\times \left(4\right)\left(1\right)$ $[\because$ EAN rule is satisfied$]$

$z=36-8$

$\Rightarrow 28$.

$\therefore$ Atomic number of $M=28$.