Ammonia is a stronger ligand than is the chloride ion. What does this statement mean?
That NH3i will coordinate with NH3 given the choice between Cl and NH3.
The statement "Ammonia is a stronger ligand than the chloride ion" means that ammonia (NH3) has a higher affinity or ability to bond with a metal ion in a complex compared to the chloride ion (Cl-).
To understand why ammonia is a stronger ligand than the chloride ion, we need to consider several factors:
1. Charge: Both ammonia and chloride ions are negatively charged ligands. However, the chloride ion carries a single negative charge (Cl-), while ammonia carries no net charge. This neutral charge of ammonia allows it to form stronger bonds with metal ions compared to the negatively charged chloride ion.
2. Size: The size of the ligand also plays a role in its bonding ability. Ammonia is a small molecule, consisting of a central nitrogen atom bonded to three hydrogen atoms. In contrast, the chloride ion is larger due to its greater number of electrons. This size difference allows ammonia to form more efficient coordination bonds with metal ions.
3. Electron donation: As a Lewis base, ammonia has a lone pair of electrons on its nitrogen atom. This lone pair can donate electrons to the metal ion, forming a coordinate bond. This electron donation enhances the bonding strength between ammonia and the metal ion. On the other hand, the chloride ion's electron density is spread over the entire ion, making it less efficient in donating electrons.
Considering these factors, ammonia's ability to form stronger bonds with metal ions makes it a stronger ligand compared to the chloride ion.