Which of the following oxides of nitrogen is neutral?

Which of the following oxyacids has an $X-O-X$ linkage?

$NH_3 + O_2 \xrightarrow[500 \ K]{Pt} W + H_2O$
$W + O_2 \rightleftharpoons X$
$X + H_2O \rightleftharpoons Y + W$
Which of the following statements is correct?

In the following reaction sequence,the compound $C$ is $Al + N_2$ $\xrightarrow{\Delta} (A)$ $\xrightarrow{H_2O} B (ppt) + C_{(g)}$

The number of $P-O$ bonds in $P_4O_6$ is:

Nitric acid forms an oxide of nitrogen on reaction with $P_{4}O_{10}$. Write the reaction involved. Also,write the resonating structures of the oxide of nitrogen formed.