Hybridization Mnemonics (sp, sp², sp³, sp³d, sp³d²) –
1. Hybridization Formula
Hybridization = No. of sigma bonds + No. of lone pairs
Mnemonic: “Count Bonds & Lone Pairs!”
2. Hybridization Types & Shapes
| Hybridization | Shape | Example | Mnemonic |
|---|---|---|---|
| sp | Linear (180°) | BeCl₂, C₂H₂ | “Single Pair → sp” (2 regions) |
| sp² | Trigonal Planar (120°) | BF₃, C₂H₄ | “Double Trouble → sp²” (3 regions) |
| sp³ | Tetrahedral (109.5°) | CH₄, NH₃ | “Three-Dee → sp³” (4 regions) |
| sp³d | Trigonal Bipyramidal (90°, 120°) | PCl₅ | “Five Alive → sp³d” (5 regions) |
| sp³d² | Octahedral (90°) | SF₆ | “Six Fix → sp³d²” (6 regions) |
Mnemonic for Order:
“Single, Double, Three-Dee, Five Alive, Six Fix!”
3. Lone Pairs Affect Shape (VSEPR Theory)
- Lone pairs repel more → distort shape
- sp³ (4 regions) → 1 lone pair = Trigonal Pyramidal (NH₃)
- sp³ (4 regions) → 2 lone pairs = Bent (H₂O)
Mnemonic: “Lone Pairs Push Bonds Away!”
4. Quick Trick to Find Hybridization
- Count attached atoms + lone pairs:
- 2 → sp
- 3 → sp²
- 4 → sp³
- 5 → sp³d
- 6 → sp³d²
Mnemonic: “2-SP, 3-SP², 4-SP³, 5-SP³D, 6-SP³D²!”
5. Examples for Practice
- CO₂ (sp) → 2 sigma bonds (linear)
- C₂H₄ (sp²) → 3 regions (trigonal planar)
- NH₃ (sp³) → 4 regions (tetrahedral but pyramidal due to lone pair)
- PCl₅ (sp³d) → 5 regions (trigonal bipyramidal)
- SF₆ (sp³d²) → 6 regions (octahedral)
Mnemonic: “Be Straight (sp), Be Flat (sp²), Be 3D (sp³), Be Expanded (sp³d, sp³d²)!”
Bonus: Hybridization in Organic Chemistry
- Alkanes (C-C single bonds) → sp³
- Alkenes (C=C double bonds) → sp²
- Alkynes (C≡C triple bonds) → sp
Mnemonic: “Single (sp³), Double (sp²), Triple (sp)!”
