Question

If EAN of a central metal ion $X^{-2}$ in a complex is $34$ and atomic number of $X$ is $28$. The number of monodentate ligands present in complex is:

• A. 3
• B. 4
• C. 6
• D. 2

Answer 1

The correct option is D 2

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.

$EAN=34$

$\Rightarrow Z-x+2nL=34$

$\Rightarrow 28-(-2)+2\left(n\right)\left(1\right)=34$

$\Rightarrow n=\frac{34-30}{2}=\frac{4}{2}=2$