IB CHEMISTRY

HL Only

2.2.13 Expanded Octet & Hybridization

Geometries for 5 and 6 electron domains.

Hybridization

4 equivalent hybrid orbitals (1s + 3p). 109.5° angle.

Hybrid Orbital (Bonding)

5 Electron Domains

Lone PairsGeometryAnglesExample
0Trigonal Bipyramidal90°, 120°, 180°PCl₅
1See-saw90°, 120°, 180°SF₄
2T-shaped90°, 180°ClF₃
3Linear180°I₃⁻

6 Electron Domains

Lone PairsGeometryAnglesExample
0Octahedral90°, 180°SF₆
1Square Pyramidal90°, 180°BrF₅
2Square Planar90°, 180°XeF₄