Chemistry · Ch 10 — Chemical Bonding
Bond Order
10.5.2
Bond Order
Bond order is the number of bonds formed between two bonded atoms in a molecule. In simple Lewis theory, bond order equals the number of shared electron pairs between the two bonded atoms.
- A single shared pair gives bond order 1 (e.g. H-H in H₂; likewise the central atom's bonds in H₂O, HCl, or methane are all single bonds of order 1).
- Two shared pairs give bond order 2 (e.g. O=O in O₂; C=O in formaldehyde, HCHO; C=C in ethylene, C₂H₄).
- Three shared pairs give bond order 3 (e.g. N≡N in N₂; C≡N in HCN). …
Table 10.2Bond order of some common bonds
| S.No | Molecule | Bonded atoms | Bond order |
|---|---|---|---|
| 1 | H₂ | H-H | 1 |
| 2 | O₂ | O=O | 2 |
| 3 | N₂ | N≡N | 3 |
| 4 | HCN | C≡N | 3 |
| 5 | HCHO | C=O | 2 |