Question

The non-existant metal carbonyl among the following is

• A. $Cr(CO)_{6}$
• B. $Mn(CO)_{5}$
• C. $Ni(CO)_{4}$
• D. $Fe(CO)_{5}$

Answer 1

Answer: (B)

$Mn(CO)_{5}$

Answer 2

Usually, metal carbonyls follows EAN rule.
Among the given, $Mn( CO )_{5}$
does not follow EAN rule, so it does not exist.
EAN = atomic no. of metal + electrons of ligands
$36 \neq 25+(5 \times 2) \neq 35$