The formula of the vapour state of white phosphorus is ......

On heating lead $(II)$ nitrate gives a brown gas $'A'$. The gas $'A'$ on cooling changes to a colourless solid $'B'$. Solid $'B'$ on heating with $NO$ changes to a blue solid $'C'$. Identify $'A'$,$'B'$ and $'C'$,write the reactions involved,and draw the structures of $'B'$ and $'C'$.

Which form of phosphorus is thermodynamically most stable?

Which of the following is an ionic compound?

The mixture of $B$ and $C$ are :
$NO \xrightarrow{O_2} A \rightleftharpoons D$
$A \xrightarrow{NaOH \ (aq.)} [B + C]$

Haber process is used for the production of which of the following?