Question

Which one of the following oxides is expected to exhibit paramagnetic behavior?
A. $CO_{2}$
B. $SO_{2}$
C. $ClO_{2}$
D. $SiO_{2}$

Answer 1

In determining which compound exhibits paramagnetic behavior, we first count the number of valence electrons. The number of valence electrons defines the behaviour of the material.

Complete step by step answer:
The presence of an unpaired electron defines the paramagnetism of the compound. If the number of valence electrons is even, then the compound is diamagnetic, but if the number is odd, then the compound is paramagnetic. Due to the presence of the unpaired electron in the structure of $ClO_{2}$, it shows paramagnetic behavior. The paramagnetic behavior can be better defined by the calculation of the Valence Electron(VE) present in the compound.
->$ClO_2$ has (7+6+6=19VE). The calculation clearly shows that Valence electrons are odd, confirming the presence of an unpaired electron.
->In the case of $CO_{2}$ (4+62), the number of Valence Electrons is 16; that is, they are even, which means it exhibits diamagnetic behavior.
->In the case of $SO_{2}$ (6+62), the number of Valence Electrons is 18; that is, they are even, which means it exhibits diamagnetic behavior.
->In the case of $SiO_{2}$ (4+6*2), the number of Valence Electrons is 16; that is, they are even, which means it exhibits diamagnetic behavior.
Hence the correct answer is $ClO_{2}$.

**Therefore option C. $ClO_{2}$is correct.

Note:**
It is important for us to learn the atomic number of each element to be aware of the overall number of valence electrons in the given compounds. One should know the electron filling concept by the Molecular orbital theory.