$A$ colourless gas with the smell of rotten fish is

Among the hydrides $NH_3, PH_3,$ and $BiH_3$, the hydride with the highest boiling point is $X$ and the hydride with the lowest boiling point is $Y$. What are $X$ and $Y$ respectively?

Which of the following compounds does not give an oxyacid of the central atom on hydrolysis?

What are the number of $P - O - P$ bridges in phosphorus pentoxide and phosphorus trioxide,respectively?

Pure $N_2$ gas is obtained from

Which of the following is a mixed anhydride?