Find the temperature in degree Celsius if volume and pressure of $2 \ mol$ ideal gas is $20 \ dm^3$ and $4.926 \ atm$ respectively. $(R = 0.0821 \ dm^3 \ atm \ K^{-1} \ mol^{-1})$

At $273\,K$,$Pd$ vs $P$ is plotted for various gases $1, 2, 3, 4$. Assuming ideal behaviour for four gases $N_2, He, CO_2$ & $H_2$. The correct combination is [$P$ denotes pressure in atmosphere & $d$ denotes density in $g/L$]

The density of Neon will be highest at

The densities of $2$ gases are in the ratio $1:2$ and their temperatures are in the ratio $2:1$. What is the ratio of their respective pressures?

If a gas occupies $1 \, L$ volume at atmospheric pressure,what will be the volume of the same amount of gas at $750 \, mm \, Hg$ pressure at the same temperature?

At what temperature will the volume of a gas be halved if the initial temperature is $17^{\circ}C$ and the pressure remains constant (in $^{\circ}C$)?