Question

EAN Of $Fe$ is …….$Fe{\left( {{C_2}{O_4}} \right)_3}^{3 - }$
$\left( a \right)27$
$\left( b \right)24$
$\left( c \right)35$
$\left( d \right)29$

Answer 1

Hint:Coordination complex consists of central metal , surrounded by ions which are called ligands. Example vitamin ${B_{12}}$ is one example of coordination complex. In which the central metal is cobalt and ligands are nitrogen.

Complete step by step answer:
Ligand is an ion or molecule which is neutral in nature , that bonds with the central metal atom and forms a complex . ligands are of two types Lewis acid and Lewis base.
Lewis acids are the one which accept electrons and Lewis base is which donate electrons .
EAN is an effective atomic number . It is the total number of electrons surrounding the nucleus of the metal in a metal complex . EAN rules decide the stability of a complex. EAN is generally equal to nearest noble gas .
$EAN = Z - X + 2nL$
Here , $Z = $atomic number of the metal in a complex
$X = $Oxidation state of metal
$n = $number of ligand
$L = $number of coordinate bonds formed by ligands
Now , EAN of $Fe{\left( {{C_2}{O_4}} \right)_3}^{3 - }$
Here atomic number of ferrous is $26$
Oxidation state of central metal which is ferrous is $3$
Number of coordination bond is $2$
Number of ligands are $3$
So putting the values $EAN = 26 - 3 + 12$
$EAN = 35$
So, the option $\left( c \right)$ is correct.
Additional information : The EAN rule is important for the recognition of how protons interact with a substance. There are many types of ligands depending upon the number of atoms in the ligand forming bond with the central metal . Monodentate ligand is one who has one atom which can coordinate with central metal . Bidentate ligand in which two atoms can form coordinate bonds . similarly tridentate ligands and tetradentate ligands have three and four atoms respectively .

Note:
 Just like EAN , there is another rule which is known as the $18$electron rule . in this rule the total electrons comes to be $18$. But in EAN rule it can come to the nearest noble gas electronic configuration .