What is the effective atomic number of the metal atom in Fe(CO)5 ?

Question

What is the effective atomic number of the metal atom in Fe(CO)5 ? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

Definition:
In a coordination compound, the EAN (Effective atomic number) is the total number of electrons around the central metal ion present in a complex.
It can be calculated using the formula

E A N = Z - X + Y

Z =

atomic number of the metal

X =

oxidation number of the central metal

Y =

number of electrons donated by the ligands i.e.

2 \times

Coordination number
Calculation:
For the given coordination complex

F e (CO)_{5}

Z = 26

(for

F e

)

X = 0

(oxidation state of

F e

in given complex)

Y = 10

(each

CO

ligand contributes

2

electrons)
Thus, the

E A N

value of given complex,

E A N = 26 - 0 + 10 = 36

E A N = 36

Q. What is the effective atomic number of the metal atom in Fe(CO)5​ ?

Q. What is the effective atomic number of the metal atom in $F e (CO)_{5}$ ?