NEET Chemical Bonding Complete Guide: VSEPR, Hybridization & MOT
Master Chemical Bonding for NEET with this comprehensive guide covering VSEPR theory, hybridization, molecular orbital theory, and bond parameters.
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Chemical Bonding is one of the highest weightage chapters in NEET Chemistry, contributing 8-10 questions (32-40 marks). This chapter is conceptual and highly scoring if fundamentals are clear.
Types of Chemical Bonds
Ionic Bond
- Transfer of electrons
- Between metal and non-metal
- Example: NaCl, MgO
- Properties: High melting point, conducts electricity in molten state
Covalent Bond
- Sharing of electrons
- Between non-metals
- Example: H2, O2, CH4
- Properties: Low melting point, poor conductor
Coordinate Bond
- Both electrons from same atom
- Example: NH3 → BF3, H3O+
VSEPR Theory
Valence Shell Electron Pair Repulsion Theory
Basic Principles
- Electron pairs repel each other
- Repulsion order: lp-lp > lp-bp > bp-bp
- Shape determined by total electron pairs
Common Shapes
| Formula | Lone Pairs | Bond Pairs | Shape | Example | Bond Angle |
|---|---|---|---|---|---|
| AB2 | 0 | 2 | Linear | CO2 | 180° |
| AB3 | 0 | 3 | Trigonal planar | BF3 | 120° |
| AB2E | 1 | 2 | Bent | H2O | 104.5° |
| AB4 | 0 | 4 | Tetrahedral | CH4 | 109.5° |
| AB3E | 1 | 3 | Pyramidal | NH3 | 107° |
| AB5 | 0 | 5 | Trigonal bipyramidal | PCl5 | 90°, 120° |
| AB6 | 0 | 6 | Octahedral | SF6 | 90° |
Hybridization
sp Hybridization
- 1s + 1p = 2 sp orbitals
- Linear geometry (180°)
- Example: BeC12, C2H2
sp² Hybridization
- 1s + 2p = 3 sp² orbitals
- Trigonal planar (120°)
- Example: BF3, C2H4
sp³ Hybridization
- 1s + 3p = 4 sp³ orbitals
- Tetrahedral (109.5°)
- Example: CH4, NH3, H2O
sp³d Hybridization
- Trigonal bipyramidal
- Example: PCl5
sp³d² Hybridization
- Octahedral
- Example: SF6
Molecular Orbital Theory
Key Concepts
- Atomic orbitals combine to form molecular orbitals
- Bonding MO (lower energy)
- Antibonding MO (higher energy)
Bond Order Formula
Bond Order = (Nb - Na) / 2
- Nb = electrons in bonding MO
- Na = electrons in antibonding MO
Magnetic Properties
- Bond order > 0: Stable molecule
- Unpaired electrons: Paramagnetic
- All paired: Diamagnetic
High-Yield Topics
- VSEPR shapes (4-5 questions)
- Hybridization (2-3 questions)
- Bond parameters (1-2 questions)
- Molecular orbital theory (1-2 questions)
Master Chemical Bonding and secure 32-40 marks!
Frequently Asked Questions
Common questions about this topic.
No, VSEPR is easy if you practice. Learn the basic shapes and remember that lone pairs repel more than bond pairs. Practice 50+ molecules and you'll master it.
Count steric number (bond pairs + lone pairs). sp=2, sp²=3, sp³=4, sp³d=5, sp³d²=6. This works for 90% of molecules.
MOT contributes 1-2 questions. Focus on bond order calculation and magnetic properties of O2, N2, and F2. Don't go too deep into MO diagrams.
Covalent bonding (VSEPR, hybridization) has higher weightage (6-7 questions). Ionic bonding contributes 2-3 questions. Master both but prioritize covalent.