Among the oxides of nitrogen $N_2O_3$,$N_2O_4$,and $N_2O_5$,the molecule$(s)$ having nitrogen-nitrogen bond is/are

Describe the methods of preparation,properties,and uses of dinitrogen gas $(N_2)$.

The maximum covalency of a non-metallic group $15$ element '$E$' with the weakest $E-E$ bond is:

Consider two reactions:
$(I) \, Zn + \text{conc. } HNO_3 \text{ (hot)} \to Zn(NO_3)_2 + X + H_2O$
$(II) \, Zn + \text{dil. } HNO_3 \text{ (cold)} \to Zn(NO_3)_2 + Y + H_2O$
Compound $X$ and $Y$ are respectively:

Which of the following reactions correctly represent the products formed upon heating?
$(a) \ NH_4NO_2 \xrightarrow{\Delta } N_2 + 2H_2O$
$(b) \ NH_4NO_3 \xrightarrow{\Delta } N_2O + 2H_2O$
$(c) \ Na_2CO_3 \xrightarrow{\Delta } Na_2O + CO_2$
$(d) \ NH_4Cl \xrightarrow{\Delta } NH_3 + HCl$

Which of the following has the lowest boiling point?