Yes, H<sub>2</sub>O is a ligand.
Understanding Ligands
A ligand is a molecule or ion that binds to a central metal atom or ion to form a coordination complex. Ligands donate electron pairs to the metal center, forming a coordinate covalent bond.
Why H<sub>2</sub>O is a Ligand
Water molecules have two lone pairs of electrons on the oxygen atom. These lone pairs can be donated to a metal ion, forming a coordinate covalent bond and making water a ligand.
Examples of H<sub>2</sub>O as a Ligand
- Hydrated Metal Ions: Many metal ions in solution are surrounded by water molecules, forming hydrated complexes. For example, the hydrated copper(II) ion, [Cu(H<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup>, is a common example.
- Coordination Compounds: Water is a common ligand in many coordination compounds, such as [Co(H<sub>2</sub>O)<sub>6</sub>]Cl<sub>3</sub>.
Conclusion
In conclusion, H<sub>2</sub>O is a ligand because it can donate a pair of electrons to a metal center, forming a coordinate covalent bond.
