Which of the following processes is used for the production of $HNO_3$ to obtain a good yield?

The minimum temperature required for a non-catalytic reaction between $N_2$ and $O_2$ is (in $K$)

What is expected to happen when phosphine gas is mixed with chlorine gas?

Which is the strongest Lewis base among the following?

Two oxides of nitrogen,$NO$ and $NO_2$,react together at $253 \ K$ to form a compound of nitrogen $X$. $X$ reacts with water to yield another compound of nitrogen $Y$. The shape of the anion of $Y$ is:

Name three oxoacids of nitrogen. Write the disproportionation reaction of that oxoacid of nitrogen in which nitrogen is in $(+3)$ oxidation state.