Ammonia is dried over

In an Ostwald process:
$NH_3 + O_2 \xrightarrow[Pt]{\Delta} x + H_2O$
$x + O_2 \to y$
$y + H_2O (excess) \to x + z$
The incorrect option is:

When heated $NH_3$ is passed over $CuO$,the gas evolved is:

Which of the following is an ionic compound?

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

In the hydrides of the nitrogen group,the $H-M-H$ bond angle gradually approaches $90^o$ as we move from $N$ to $Sb$. This indicates that gradually.....