According to VSEPR theory, the electron pairs around a central atom will arrange themselves in a way that minimizes electron-electron repulsion. In H3O+, the oxygen atom has four electron pairs: three bonding pairs and one lone pair. The three bonding pairs are arranged in a trigonal planar geometry, while the lone pair occupies an equatorial position.
The hybridization of the oxygen atom in H3O+ is sp3. This means that the oxygen atom uses one s orbital and three p orbitals to form four equivalent hybrid orbitals. The hybrid orbitals are then used to form the three covalent bonds with hydrogen atoms. The lone pair of electrons occupies one of the sp3 hybrid orbitals, which is oriented away from the bonding pairs.
The sp3 hybridization of the oxygen atom in H3O+ results in a tetrahedral electron pair geometry. The bond angle between the O-H bonds is 109.5 degrees.
