Question

why the following molecules do not obey octet rule?

SO2, SF4, NO2, SO3. NO , ,BF3, PCl3

Answer 1

• S has 6 valence electrons while O also has 6 valence electrons. When O combines with S, S has more than 8 electrons around it.
• S has 6 electrons, 4 of which are used up for the formation of 4 bonds with 4 F atoms in this way the number of electrons around S becomes10.
• N has 5 valence electrons and O has 6. When these two combines to form NO and NO2 , both of these dont obey octet rule as they involve dative binding.
• B has 3 electrins and forms 3 bonds with F atoms in this way there are only 56 electrons around B atom.
• PCl₃ follow octet rule