Phosphine $[PH_{3(g)}]$ decomposes to produce vapours of phosphorus $(P_4)$ and $H_2$ gas. What will be the change in volume when $100 \ mL$ of phosphine is decomposed?

If $10$ volumes of dihydrogen gas react with $5$ volumes of dioxygen gas, how many volumes of water vapour would be produced?

At $NTP$,the density of a gas,whose molecular weight is $45$,is ............. $g \ L^{-1}$.

In the following reaction sequence,the $\%$ yield for reaction $I$ is $60 \%$ and that of reaction $II$ is $50 \%$. The overall yield of the complete reaction is $..........\%$ [nearest integer].

Volume of air required to completely burn $10 \ L$ of $C_2H_4$ is ................ $L$ (assume all volumes are measured at the same temperature and pressure,and air contains $20\%$ oxygen by volume).

If $1$ mole of $N_2$ occupies a volume of $22.4 \, L$ at $NTP$,what is the density of $N_2$ in $g/L$?