Question

How would you react to the statement that the electronegativity of N on Pauling scale is 3.0 in all the nitrogen compounds?

Answer 1

Reaction to the Statement

The statement “the electronegativity of N on Pauling scale is 3.0 in all nitrogen compounds” is incorrect.

Reason (Conceptual)

Electronegativity is the tendency of an atom in a molecule to attract the shared pair of electrons towards itself.

It is not a fixed constant for an element; it is a variable property that depends on:

• The oxidation state of the atom.
• The nature and electronegativity of the atoms bonded to it (chemical environment).
• The state of hybridisation (percentage of s-character).

Effect of Hybridisation (LaTeX)

Greater s-character in the orbital containing the bonding electrons increases electronegativity: \[ sp \;>\; sp^{2} \;>\; sp^{3} \] So nitrogen in an \(sp\)-hybridised state will be more electronegative than in an \(sp^{3}\) state.

Effect of Chemical Environment

Nitrogen does not have the same effective electron‑attracting power in all compounds.

For example, the electronegativity of N is different in \(\ce{NH3}\) and \(\ce{NO2}\) because the atoms attached to N and its oxidation state are different in these molecules.

Conclusion (Short)

The quoted value 3.0 on the Pauling scale is only an approximate/standard value for nitrogen, not its exact value in every nitrogen compound.