AP Chemistry / Unit 2: Compound Structure and Properties
2.7 VSEPR and Bond Hybridization
Notes
Electron domains spread out as far as possible:
| Domains | Shape (no lone pairs) | Angle | Hybrid |
|---|---|---|---|
| 2 | linear | 180° | sp |
| 3 | trigonal planar | 120° | sp² |
| 4 | tetrahedral | 109.5° | sp³ |
- Lone pairs change the molecular shape (water is bent, ammonia is trigonal pyramidal).
- A single bond is σ; a double bond is 1 σ + 1 π.
Practice
The shape of $\mathrm{NH_3}$:
4 domains, 1 lone pair.
Carbon in $\mathrm{CO_2}$ is hybridized:
Two electron domains.
A triple bond contains:
The first bond is always σ.
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