N₃H is represented as

Nitrogen attached with double bonds has oxidation number:

Correct option is B

The correct answer is: (b) +3
Oxidation Number of Nitrogen with Double Bonds in Hydrazoic Acid (HN₃):
Hydrazoic acid has the molecular formula HN₃, and one of its resonance structures is:
H–N⁻=N⁺=N
In this structure:
· The first nitrogen is bonded to hydrogen and another nitrogen: usually has oxidation number –3.
· The third nitrogen has a negative formal charge: oxidation number –1.
· The central nitrogen is double bonded to both adjacent nitrogen atoms, and carries a positive charge.
To calculate the oxidation state of the central nitrogen:
Let the oxidation numbers be:
· First N (bonded to H) = –3
· Third N = –1
· Central N = x
· Hydrogen = +1
Using the rule that the total oxidation number in a neutral compound is 0:
(+1) + (–3) + x + (–1) = 0 → x = +3