In which of the following ranges can nitrogen exhibit various oxidation states?

$P_4 + 3NaOH + 3H_2O \to A + 3NaH_2PO_2$. Here,$A$ is:

Reaction of thionyl chloride with white phosphorus forms a compound $[A]$,which on hydrolysis gives $[B]$,a dibasic acid. $[A]$ and $[B]$ are respectively

The number of $P-O-P$ bridges in the structures of phosphorus pentoxide $(P_4O_{10})$ and phosphorus trioxide $(P_4O_6)$ are respectively ....

Ammonia can be dried by

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