The reaction of elemental $P_4$ and aqueous $NaOH$ gives

Which of the following reactions is a part of the large-scale industrial preparation of nitric acid?

In $P_4O_6$,how many oxygen atoms are attached to each phosphorus atom?

Which of the following is a good oxidising agent?

$8 NH_{3} + 3 Cl_{2} \rightarrow X$ (Excess $NH_{3}$)
$NH_{3} + 3 Cl_{2} \rightarrow Y$ (Excess $Cl_{2}$)
What are $X$ and $Y$ in the above reactions?

Which of the following oxides of nitrogen is the anhydride of nitrous acid?