Hybridization Lecture Notes

Introduction to Hybridization

• Valence Bond Theory: Uses quantum mechanics to explain chemical bonding along with molecular orbital theory.
• Definition: Process in chemistry where atomic orbitals combine to form new hybridised orbitals with different energies and shapes.

Characteristics of Hybridization

• Occurs with orbitals of the same atom or ion having similar energies.
• Number of hybrid orbitals equals the number of orbitals involved.
• Hybrid orbitals are more stable and have comparable energy and shape compared to pure atomic orbitals.
• Aims to create equivalent orbitals with maximum symmetry.
• Theoretical concept to describe molecular behavior.
• Hybrid orbitals are oriented in specific directions for stability and proper molecular shape.

Types of Hybridization

1. sp Hybridization

• Combines one s- and one p-orbital.
• Forms two sp hybrid orbitals with linear geometry, bond angle of 180°.
• Equal s and p character (50% each).
• Example: BeCl2 formation.

2. sp2 Hybridization

• Combines one s- and two p-orbitals.
• Forms three sp2 hybrid orbitals with trigonal planar geometry, bond angle of 120°.
• s character is 33.3%, p character is 66.66%.
• Found in molecules where a central atom is connected to three other atoms.

3. sp3 Hybridization

• Combines one s- and three p-orbitals.
• Forms four sp3 hybrid orbitals with tetrahedral geometry, bond angle of 109.28°.
• s character is 25%, p character is 75%.
• Example: Ethane and methane.

4. sp3d Hybridization

• Combines one s-, three p-, and one d-orbital.
• Forms five sp3d hybrid orbitals with trigonal bipyramidal geometry.
• Equatorial orbitals at 120° and axial orbitals at 90°.
• Example: Phosphorus Pentachloride (PCl5).

5. sp3d2 Hybridization

• Combines one s-, three p-, and two d-orbitals.
• Forms six sp3d2 hybrid orbitals with octahedral geometry.
• Angles are 90°.

Conclusion

• Hybridization not only explains bonding but also molecular shapes.
• Considered a powerful evolutionary force, affecting genetic diversity, new species creation, and extinction through genetic assimilation.

FAQs on Hybridization

• Necessity: Keeps electrons stable in their orbitals.
• Rules: Govern how hybridization is achieved.
• Drawbacks: Includes certain evolutionary consequences.

Additional Resources

• Related topics include Actinides, Aluminium Chloride Structure, Covalent and Ionic Bonds, and more.
• Popular exams and study material available for various competitive exams like IIT JEE, UPSC, NEET UG, etc.