Number of molecules from the following which are exceptions to octet rule is . CO2, NO2, H2SO4, BF3, CH4, SiF4, ClO2, PCl5, BeF2, C2H6, CHCl3, CBr4
Answer
6
Solution
Incomplete octet: BF3 (B: 6 e), BeF2 (Be: 4 e)
Odd-electron molecules: NO2, ClO2
Expanded octet: H2SO4 (S: 12 e), PCl5 (P: 10 e)
Octet obeyed: CO2, CH4, SiF4, C2H6, CHCl3, CBr4
∴ exceptions = 6
Answer: 6