Question

Give a reason for the following:
-\[PC{l_5}\] acts as an oxidizing agent.
-Dinitrogen is chemically inert.

Answer 1

Hint: Oxidizing agent: It is a molecule or compound which gains electrons to get reduced itself and oxidizes the other reactant present in a chemical reaction. These are important in industrial use because of their use in processes like bleaching, purifying, etc.

Complete answer:
\[PC{l_5}\] acts as an oxidizing agent:
We need to check the oxidation state of phosphorus in the given compound before categorizing it as an oxidizing or a reducing agent. Let the oxidation state of phosphorus be \[x\] and the formal charge on chlorine atoms is \[( - 1)\].
Therefore,
\[x - 5 = 0\]
\[\therefore x = + 5\]
Oxidation state of phosphorus in \[PC{l_5}\] is \[ + 5\].
We know that phosphorus atoms can only exist in two oxidation states i.e., \[ + 3\] and \[ + 5\]. But in \[PC{l_5}\], the phosphorus atom is already at its highest oxidation state which means it cannot donate electrons. So, it cannot act as a reducing agent.
Although it can accept electrons to change its oxidation state from \[ + 5\] to \[ + 3\] and get reduced during a chemical reaction. Hence, \[PC{l_5}\] acts as an oxidizing agent.
Dinitrogen is chemically inert:
In nitrogen atoms, there are five electrons present in the outermost valence shell and hence nitrogen is trivalent for most of its compound. In dinitrogen molecules, there exists a triple bond between two nitrogen atoms \[(N \equiv N)\] and the energy required to break this bond is very high because of strong \[p - p\] overlapping of orbitals. Therefore, it does not show any reaction at room temperature and hence it is chemically inert.

Note:
The intensity of covalent bonding directly varies with the extent of overlap and the degree of overlap which relates it to the directional nature of the orbitals. Because \[p - p\]orbital overlap has more directional nature than that of \[s - p\] and \[s - s\]. Therefore, \[p - p\]orbital overlap is the strongest overlapping.