Question

Which of the following coordinate complexes contains one or more neutral ligand / ligands in its coordination sphere?

• A. Potassium trioxalatoaluminate(III)
• B. Pentaammineaquacobalt(III) iodide
• C. Sodium hexanitrocobaltate(III)
• D. Hexacyanoferrate(II) ion

Hint:

Check each complex for ligands like NH3 or H2O, which are neutral molecules.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
A neutral ligand is a molecule with no charge, such as \(\text{NH}_{3}\) (ammine) or \(\text{H}_{2}\text{O}\) (aqua).
We look inside the coordination sphere only.

Step 2: Check each complex
(A) \(\text{K}_{3}[\text{Al(C}_{2}\text{O}_{4}\text{)}_{3}]\): oxalate is an anion.
(B) \([\text{Co(NH}_{3}\text{)}_{5}\text{(H}_{2}\text{O)}]\text{I}_{3}\): ammine and aqua are both neutral.
(C) \(\text{Na}_{3}[\text{Co(NO}_{2}\text{)}_{6}]\): nitro is an anion.
(D) \([\text{Fe(CN)}_{6}]^{4-}\): cyano is an anion.

Step 3: Conclusion
Only pentaammineaquacobalt(III) iodide has neutral ligands.

Final Answer:
The complex with neutral ligands is pentaammineaquacobalt(III) iodide, option (B). \[ \boxed{\text{(B) }\text{Pentaammineaquacobalt(III) iodide}} \]