Iron carbonyl, `Fe(CO)_5` is

Options

A. tetranuclear
B. mononuclear
C. trinuclear
D. dinuclear

Answer

B

Explanation

Let's calculates its effective atomic number `(EAN)`:
`EAN = (Z) - (O.N) + 2` (no. of ligands)
`= (26) - (0) + 2 (5) = 36`
This `EAN` is equal the atomic number of nearest noble gas `(Kr)`. Since `Fe (CO)_(5)` follows `EAN`, there is no possibility of another central metal as well ligand. thus it si mononuclear.