Chapter 8 · Chemistry
Shapes of Carbon Compounds: sp³, sp², sp
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Methane, ethene and ethyne all contain carbon but have different shapes. Hybridisation, and a quick way to find it.
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Key points
- sp³: 4 single bonds, tetrahedral, about 109.5°, as in methane.
- sp²: one double bond, trigonal planar, 120°, as in ethene.
- sp: one triple bond, linear, 180°, as in ethyne.
- Shortcut: count the groups around carbon: 4 is sp³, 3 is sp², 2 is sp.
- More s character (25%, 33%, 50%) means shorter, stronger bonds.
At a glance
| Groups | Hybridisation | Shape | Angle | s character |
|---|---|---|---|---|
| 4 | sp³ | Tetrahedral | 109.5° | 25% |
| 3 | sp² | Trigonal planar | 120° | 33% |
| 2 | sp | Linear | 180° | 50% |
Try it yourself
Goal: Build the bonds around one carbon and find its hybridisation and shape.
- Add single, double or triple bonds until carbon has 4.
- Read the groups, hybridisation and shape.
- Try the examples.
- Check the allene carbon: two double bonds, 2 groups, sp.
Quick quiz
3 questions. Choose an answer for each, then submit to see your score and the explanations.
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