Hydrolysis of phosphorus trichloride in water gives:

Given below are two statements:
Statement-$I$: Element '$X$' and '$Y$' are the most and least electronegative elements, respectively, among $N, As, Sb$ and $P$. The nature of the oxides $X_{2}O_{3}$ and $Y_{2}O_{3}$ is acidic and amphoteric, respectively.
Statement-$II$: $BCl_{3}$ is covalent in nature and gets hydrolysed in water. It produces $[B(OH)_{4}]^{-}$ and $HCl$ in aqueous medium.

Which of the following oxides of nitrogen is the anhydride of $HNO_3$?

The correct order of boiling points of hydrides of $15^{th}$ group elements is

Nitrogen dioxide cannot be obtained by heating:

Under which of the following conditions can active nitrogen be produced by passing $N_2$ gas through an electric spark?