Question

Why is \[{{\text{N}}_{\text{2}}}\] less reactive at room temperature?

Answer 1

Hint: Before answering the question, we need to have an idea about the structure of \[{{\text{N}}_{\text{2}}}\]. And at the same time the existing chemical bonding between the atoms. Once we get a clear idea, we will be able to answer this question.

Complete step by step solution:
We first will take a look into the chemical bonding of the \[{{\text{N}}_{\text{2}}}\] molecule.

As we can see that there exists a triple bond between the \[{{\text{N}}_{\text{2}}}\] atoms. The triple bond is pretty strong.
Therefore, it needs a lot of energy to break those bonds and participate in a reaction. So nitrogen is commonly referred to as an inert gas (more abundance and low-cost).
Dissociation energy of this molecule is fairly high therefore it is less reactive at room temperature.

By Bond Dissociation energy we mean the energy that is required to break a chemical bond. It is one means by quantifying the strength of a chemical bond dissociation energy which is equal to the bond energy, only for diatomic molecules.
The other reason behind the high dissociation energy of nitrogen can also be defined from the fact that nitrogen has six more electrons in a bonding atomic orbital. So its bond order is 3. However, \[{{\text{N}}_{\text{2}}}^{+}\] has only 5 in bonding with bond order is 2.5. Bond dissociation energy is directly proportional to bond order of a molecule so it has more bond dissociation energy.

So, it is due to the high dissociation energy of \[{{\text{N}}_{\text{2}}}\] that it is less reactive at room temperature.

Note: The only way to break the \[{{\text{N}}_{\text{2}}}\] bond is the solution which involves clamshell like organic molecules that holds an atom of the metal hafnium in their opening. Two of these molecules can lock a nitrogen molecule between their metal atoms and break the first two of its bonds.
Although nitrogen makes up 78% of the atmosphere it is not used in many industrial processes as the triple bond is difficult to break.