Identify from the following a coordinate complex containing neutral...

Pentacarbonyliron(0) is $[Fe(CO)_5]$. The ligand is carbonyl (CO$), which is a neutral molecule.<br><br>Hexacyanoferrate(II) ion is$[Fe(CN)_6]^{4-}$. The ligand is cyanide (CN^-$), which is anionic.

Trioxalatocobaltate(III) ion is $[Co(C_2O_4)_3]^{3-}$. The ligand is oxalate (C_2O_4^{2-}$), which is anionic.<br><br>Sodium hexanitrocobaltate(III) is$Na_3[Co(NO_2)_6]$. The ligand is nitro (NO_2^-$), which is anionic.

Thus, pentacarbonyliron(0) contains a neutral ligand.

Answer: Pentacarbonyliron(0)