Question

Identify from the following a coordinate complex containing neutral ligand in it.

• A. Pentacarbonyliron(0)
• B. Hexacyanoferrate(II)ion
• C. Trioxalatocobaltate(III)ion
• D. Sodiumhexanitrocobaltate(III)

Hint:

Check the ligand in each complex. Carbon monoxide carries no charge, while cyanide, oxalate and nitro ligands are anions.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
A ligand is neutral if it carries no charge, for example \(\text{CO}\), \(\text{NH}_3\) or \(\text{H}_2\text{O}\). Anionic ligands include \(\text{CN}^{-}\), oxalate and \(\text{NO}_2^{-}\).

Step 2: Identify the ligands
Pentacarbonyliron(0), \([\text{Fe(CO)}_5]\): ligand \(\text{CO}\), neutral.
Hexacyanoferrate(II): ligand \(\text{CN}^{-}\), anionic.
Trioxalatocobaltate(III): ligand oxalate, anionic.
Hexanitrocobaltate(III): ligand \(\text{NO}_2^{-}\), anionic.

Step 3: Check the oxidation state
Since \(\text{CO}\) has no charge, iron in \([\text{Fe(CO)}_5]\) is in the zero oxidation state, matching the name (0).

Final Answer:
Pentacarbonyliron(0) contains a neutral ligand. \[ \boxed{\text{(A) }\text{Pentacarbonyliron(0)}} \]