Correct Answer - 2
Dinitrogen does not burn or support combustion .It is extremely unreactive towards most elements and compounds because of the stability of nitrogen -nitrogen triple bond. The `N equiv N` bond enthalpy is `942" kJmol"^(-1)` compared with `167" kJmol"^(-1)` for the `N-N` bond enthalpy.
Thus `N_(2)(g)` is used to provide an inert atmosphere during welding and for certain metallurgical processes where oxidation might otherwise occur and for filling electrical lamps.
