In which of the following compounds does hydrolysis take place through $S_N^1$ and $S_N^2$ mechanisms respectively?

Concentrated $HNO_3$ is a yellow-colored liquid due to:

For the reaction $N_{2(g)} + O_{2(g)} \xrightarrow{\Delta} 2NO_{(g)}$,the temperature required is ........... $K$.

Which pair of oxyacids of phosphorus contains $P-H$ bonds?

Which of the following is an acidic oxide?

The following are some statements related to $VA$ group hydrides:
$I$. Reducing property increases from $NH_3$ to $BiH_3$.
$II$. Tendency to donate lone pair decreases from $NH_3$ to $BiH_3$.
$III$. Thermal stability of hydrides decreases from $NH_3$ to $BiH_3$.
$IV$. Bond angle of hydrides decreases from $NH_3$ to $BiH_3$.
The correct statements are: