Hybridisation in Chemistry

Study Notes

Hybridisation in Chemistry

Definition: Hybridisation is the mixing of atomic orbitals to produce new hybrid orbitals that can form sigma bonds and accommodate lone pairs of electrons.
Types of Hybridisation:
1. sp Hybridisation:
  - Involves one s and one p orbital.
  - Forms two equivalent sp hybrid orbitals.
  - Geometry: Linear (180° bond angle).
  - Example: BeCl₂.
2. sp² Hybridisation:
  - Involves one s and two p orbitals.
  - Forms three equivalent sp² hybrid orbitals.
  - Geometry: Trigonal planar (120° bond angle).
  - Example: BF₃.
3. sp³ Hybridisation:
  - Involves one s and three p orbitals.
  - Forms four equivalent sp³ hybrid orbitals.
  - Geometry: Tetrahedral (109.5° bond angle).
  - Example: CH₄.
4. sp³d Hybridisation:
  - Involves one s, three p, and one d orbital.
  - Forms five equivalent sp³d hybrid orbitals.
  - Geometry: Trigonal bipyramidal (90° and 120° bond angles).
  - Example: PCl₅.
5. sp³d² Hybridisation:
  - Involves one s, three p, and two d orbitals.
  - Forms six equivalent sp³d² hybrid orbitals.
  - Geometry: Octahedral (90° bond angle).
  - Example: SF₆.
Importance of Hybridisation:
- Explains molecular geometry and bond angles.
- Helps predict the reactivity and properties of molecules.
- Provides insight into the formation of multiple bonds (e.g., double and triple bonds involve p orbitals which may not hybridise).
Hybrid Orbital Characteristics:
- Hybrid orbitals are degenerate (equal energy).
- They can form sigma (σ) bonds with other atoms.
- Unhybridised p orbitals are used to form pi (π) bonds.
Factors Influencing Hybridisation:
- The number of atoms bonded to the central atom.
- The presence of lone pairs which can affect geometry and angles.
- Electronegativity and atomic size may influence the type of hybridisation.
Applications:
- Understanding molecular structure in organic chemistry.
- Predicting the shape and reactivity of coordination compounds.
- Providing a fundamental basis for molecular orbital theory.

Hybridisation in Chemistry

Hybridisation: A process that combines atomic orbitals to create new hybrid orbitals for forming sigma bonds and accommodating lone pairs.

Types of Hybridisation

sp Hybridisation:
- Combines one s and one p orbital.
- Results in two sp hybrid orbitals.
- Configured as linear geometry with a 180° bond angle.
- Example: Beryllium chloride (BeCl₂).
sp² Hybridisation:
- Involves one s and two p orbitals.
- Produces three equivalent sp² hybrid orbitals.
- Geometry is trigonal planar, characterized by a 120° bond angle.
- Example: Boron trifluoride (BF₃).
sp³ Hybridisation:
- Formed from one s and three p orbitals.
- Creates four equivalent sp³ hybrid orbitals.
- Exhibits tetrahedral geometry with a bond angle of 109.5°.
- Example: Methane (CH₄).
sp³d Hybridisation:
- Involves one s, three p, and one d orbital.
- Produces five equivalent sp³d hybrid orbitals.
- Architecture is trigonal bipyramidal with bond angles of 90° and 120°.
- Example: Phosphorus pentachloride (PCl₅).
sp³d² Hybridisation:
- Combines one s, three p, and two d orbitals.
- Results in six equivalent sp³d² hybrid orbitals.
- Geometry is octahedral, with a bond angle of 90°.
- Example: Sulfur hexafluoride (SF₆).

Importance of Hybridisation

Aids in understanding the molecular geometry and bond angles.
Enhances prediction of molecular reactivity and physical properties.
Offers insights on multiple bonds involving p orbitals that may not undergo hybridisation.

Hybrid Orbital Characteristics

Hybrid orbitals possess equal energy levels, known as degeneracy.
Facilitate the formation of sigma (σ) bonds with other atoms.
Unhybridised p orbitals are responsible for creating pi (π) bonds.

Factors Influencing Hybridisation

The count of atoms bonded to the central atom can dictate hybridisation type.
Lone pairs present on the central atom can affect the overall geometry and bond angles.
Atomic size and electronegativity may determine the specific hybridisation form.

Applications

Critical for understanding molecular structure in systems of organic chemistry.
Essential in predicting the shapes and reactivity of coordination compounds.
Lays foundational concepts for molecular orbital theory in chemistry.

Description

Explore the concept of hybridisation in chemistry by understanding how atomic orbitals mix to form new hybrid orbitals. This quiz covers different types of hybridisation, including sp, sp², sp³, and sp³d, along with their geometries and examples. Test your knowledge on this essential topic in chemical bonding!