Number of molecules from the following which are exceptions to the octet rule is ________.
CO2, NO2, H2SO4, BF3, CH4, SiF4, ClO2, PCl5, BeF2, C2H6, CHCl3, CBr4
Correct Answer: 6
Exceptions to octet rule include molecules with incomplete octet, expanded octet and odd number of electrons.
| Molecule | Status |
|---|---|
| NO₂ | Odd electron |
| ClO₂ | Odd electron |
| BF₃ | Incomplete octet |
| BeF₂ | Incomplete octet |
| PCl₅ | Expanded octet |
| H₂SO₄ | Expanded octet |
Hence, total number of exceptions = 6.