$NH_3 + O_2 \xrightarrow[\Delta]{Pt} A + H_2O$ ;
$A + O_2 \to B$ ;
$B + O_2 + H_2O \to C$
$A, B$ and $C$ are:

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T$:
$\underline{P}Cl_3 + H_2O \longrightarrow H_3PO_3 + HCl$

Select the incorrect statement regarding trihalides $(EX_3)$ and pentahalides $(EX_5)$ of the nitrogen family.

The nitrogen oxide$(s)$ that contain$(s)$ $N-N$ bond$(s)$ is(are):
$A$. $N_2O$
$B$. $N_2O_3$
$C$. $N_2O_4$
$D$. $N_2O_5$

The number of hydroxyl group in pyrophosphoric acid is

Which of the following is the correct decreasing order of bond angles in the hydrides of group $15$ elements?