Question

What is expected to show paramagnetism?

Answer 1

Hint: Understand the term paramagnetism for compounds. Now determine the factors that are required for the compound to show paramagnetism. Based on these factors, evaluate the given compounds in options to determine the compound that will exhibit paramagnetic properties.

Complete Solution :
- Paramagnetism is a form of magnetism exhibited by some substances and compounds by which they can weakly or faintly attract materials due to an external magnetic field that is applied.
- They tend to form induced magnetic fields aligned in the direction of external magnetic fields.
One of the important factors for a compound to exhibit paramagnetism is unpaired electrons. We will calculate the total number of electrons present in the compound and then determine the paramagnetic character.
- $Cl{{O}_{2}}$:
Total number of electrons : 17 + (2 x 8) = 33

- $S{{O}_{2}}$:
Total number of electrons : 16 + (2 x 8) = 32

- $C{{O}_{2}}$:
Total number of electrons : 6 + (2 x 8) = 22

- $Si{{O}_{2}}$:
Total number of electrons : 14 + (2 x 8) = 30
In the above 4 compounds, we observe that the compound having odd number of electrons is $Cl{{O}_{2}}$ and is expected to show paramagnetism.
So, the correct answer is “Option A”.

Note: It is important to know not all compounds that have even number of electrons are non-paramagnetic. For example, an oxygen molecule is paramagnetic, although it has a total of 16 electrons. The paramagnetic property of oxygen is explained by the molecular orbital theory.