Equal masses of $H_{2(g)}$ and $He_{(g)}$ are enclosed in a container at constant temperature. The ratio of partial pressure of $H_2$ to $He$ is

If the density of a mixture of nitrogen and oxygen gases at $400 \ K$ and $1 \ atm$ pressure is $0.920 \ g \ L^{-1}$, what is the mole fraction of nitrogen in the mixture? ($R=0.082 \ L \ atm \ mol^{-1} \ K^{-1}$; assume ideal gas behavior for oxygen and nitrogen)

Select the incorrect statement using the phase diagram of a substance.

Two flasks of equal volume are filled with $N_2$ gas and connected by a thin tube of negligible volume. When both flasks are immersed in boiling water,the pressure of the gas inside the system is $0.5 \, atm$. Calculate the pressure of the system when one flask is immersed in ice water and the other is kept in boiling water. (in $, atm$)

$A$ $x : 1$ molar mixture of $He$ and $CH_4$ is contained in a vessel at $20 \ bar$ pressure. Due to a hole in the vessel,the gas mixture leaks out. If the composition of the mixture effusing out initially is $8 : 1$,then the value of $x$ will be

Two gases $X$ and $Y$ are taken in equal molar proportions. The ratio of their rates of diffusion is $1 : 2$. What will be the mole fraction of $X$ in a mixture containing $2 \ g$ of $X$ and $3 \ g$ of $Y$?