Dilute sodium hydroxide does not react with which of the following?

Consider the following statements:-
$I. \, PCl_3$ hydrolyses in the presence of moisture giving fumes of $HCl$.
$II. \, PCl_5$ exists as $[PCl_4]^+[PCl_6]^-$ in the solid state.
$III. \, $All the five bonds in the $PCl_5$ molecule are equivalent.
Choose the correct statements.

Superphosphate is the mixture of

Two oxides of nitrogen, $NO$ and $NO_2$, react together at $253 \ K$ to form a compound of nitrogen $X$. $X$ reacts with water to yield another compound of nitrogen $Y$. The shape of the anion of $Y$ is:

At high temperatures,nitrogen directly combines with

Which of the following oxides of nitrogen is coloured?