Question

In a neutral complex $\left[Fe\right(CO{)}_x]$, the value of $x$ is:

• A. $3$
• B. $4$
• C. $5$
• D. $6$

Answer 1

Answer: (C)

$5$

According to $EAN$ rule, the complex $\left[Fe\right(CO{)}_x]$ will be stable if its $EAN$ value is $36$.

$EAN=Z-X+Y$

Where,

Z= Atomic number
X = Oxidation state of metal
Y = Total number of electrons donated by ligand

So, $26-0+2x=36$

$=>x=5$

Option C is correct.