Explain hybridisation of the central atom in SiCl₄.

Given: Molecule = SiCl₄.

The central atom is the least electronegative, so silicon (Si) is central.

1. Valence electrons:

Silicon is a Group 14 element ⇒ 4 valence electrons on Si.

There are four chlorine atoms; each Cl contributes one unpaired electron in a p orbital for bonding.

2. Hybridization of Si:

To form four equivalent σ bonds, Si mixes one 3s and three 3p orbitals:

Si: sp³ hybridization ⇒ four identical sp³ hybrids, each with one electron.

3. Bond formation:

Each Si sp³ hybrid overlaps with a Cl p orbital (each holding one electron) to form four σ (sigma) bonds: Si–Cl × 4.

4. Geometry and lone pairs:

Si has no lone pairs in SiCl₄, so the geometry from sp³ hybridization is tetrahedral.

Therefore:

Hybridization (central atom, Si):sp³

Molecular shape:Tetrahedral

Cl–Si–Cl bond angle:≈ 109.5°