Which one of the following oxides is expected to exhibit paramagnetic behaviour?
- CO2
- SiO2
- SO2
- ClO2
Answer
(4) ClO2
Solution
Count the valence electrons:
CO2: 4 + 2 6 = 16; SiO2: 4 + 2 6 = 16; SO2: 6 + 2 6 = 18 (all even, all electrons paired)
ClO2: 7 + 2 6 = 19 (odd)
ClO2 is an odd-electron molecule with one unpaired electron.
ClO2 is paramagnetic.
Answer: (4)