Hybridization and Bond Angle
Hybridization
Hybridization is the process of mixing atomic orbitals to form new hybrid orbitals that are equivalent in energy and shape.
These hybrid orbitals are used to describe bonding in molecules. The type of hybridization depends on the number and type
of electron regions (bonds and lone pairs) around a central atom.
Common types of hybridization:
- sp: Linear geometry with a bond angle of approximately 180°.
- sp²: Trigonal planar geometry with a bond angle of approximately 120°.
- sp³: Tetrahedral geometry with a bond angle of approximately 109.5°.
- sp³d: Trigonal bipyramidal geometry with bond angles of 90° and 120°.
- sp³d²: Octahedral geometry with a bond angle of 90°.
Bond Angle
Bond angle is the angle formed between two bonds originating from the same atom. It is influenced by:
- Hybridization: Determines the basic geometry (e.g., 109.5° for sp³).
- Lone Pairs: Lone pairs repel bonding pairs more strongly than bonding pairs repel each other, reducing bond angles.
- Bonding Pair Repulsion: The number of bonds (single, double, triple) can affect the repulsion strength and thus alter the bond angle.
For example:
- Methane (CH₄): sp³ hybridization, tetrahedral shape, bond angle ~109.5°.
- Water (H₂O): sp³ hybridization, bent shape due to two lone pairs, bond angle ~104.5°.
- Carbon dioxide (CO₂): sp hybridization, linear shape, bond angle ~180°.
These concepts are essential for understanding the 3D structure and reactivity of molecules.
