What is the hybridization of H2O?
The correct answer and explanation is:
The hybridization of H2O (water) is sp³.
Water has two hydrogen atoms bonded to an oxygen atom. The oxygen atom, in this case, is the central atom. To understand its hybridization, consider the following:
- Electron Domain Count: The oxygen atom in H2O has two bonding pairs (from the hydrogen atoms) and two lone pairs of electrons. This gives a total of four electron domains (two bonding pairs and two lone pairs).
- Hybrid Orbitals: In order to accommodate these four electron domains, oxygen undergoes sp³ hybridization. In sp³ hybridization, one s orbital combines with three p orbitals from the oxygen atom, creating four hybrid orbitals. These hybrid orbitals are arranged in a tetrahedral geometry to minimize electron repulsion.
- Molecular Geometry: Although the hybridization of oxygen is sp³, the actual molecular geometry of H2O is bent or V-shaped due to the presence of the two lone pairs on the oxygen atom. The lone pairs occupy two of the four sp³ hybrid orbitals, leaving the remaining two hybrid orbitals to form bonds with the hydrogen atoms.
- Bond Angles: The ideal bond angle in a perfect tetrahedral geometry is 109.5°. However, because the lone pairs of electrons exert more repulsion than bonding pairs, the bond angle in H2O is reduced to approximately 104.5°, which accounts for the bent shape of the molecule.
In conclusion, despite the bent shape of water, the oxygen atom in H2O is sp³ hybridized due to the four electron domains it interacts with (two bonding pairs and two lone pairs).