Question

Nitrogen exist as a _____________ at room temperature.

• A. Monoatomic gas
• B. Diatomic gas
• C. Triatomic gas
• D. None of the options are corect

Answer 1

The correct option is B Diatomic gas

Think about the hint!
Nitrogen atom is small in size and has the tendency to form $p\pi -p\pi$ multiple bonds. In fact, the Nitrogen - Nitrogen triple bond in $N_2$ molecule has very high thermodynamic stability. It has a dissociation energy of $942kJ.mo{l}^{-1}$
This makes nitrogen exist as a diatomic gas at room temperature. Also, this increased stability of the $N\equiv N$ makes it non polar and hence the Van der Waals forces between the molecules are low. This is the reason why Nitrogen is a gas at room temperature. These reasons also make $N_2$ molecule pretty inert at ordinary temperatures and pressure(s).