The rate of diffusion of $H_2$ is .......

In which one of the following,does the given amount of chlorine exert the least pressure in a vessel of capacity $1 \ dm^{3}$ at $273 \ K$?

At $298 \ K$, a flask '$A$' of unknown volume $(V)$ contains oxygen at $5 \ atm$. Another flask '$B$' of volume $2 \ L$ contains helium at $3 \ atm$. Two flasks are connected together by a small tube of zero volume. After the two gases are completely mixed, if the resulting mixture is found to have the mole fraction of oxygen as $0.2$, the volume of flask '$A$' (in $L$) is (Assume oxygen and helium as ideal gases)

If the molar ratio of $CH_4$ and $O_2$ is $1:2$,then the ratio of the rate of diffusion of $O_2$ and $CH_4$ is respectively:

At $100\,^\circ\text{C}$ and $1 \, \text{atm}$ pressure,if the density of liquid water is $1.0 \, \text{g cm}^{-3}$ and the density of water vapor is $0.0006 \, \text{g cm}^{-3}$,then the volume occupied by water molecules in $1 \, \text{L}$ of steam is ............. $\text{cm}^3$.

The most probable velocity of a gas at $7200 \ K$ is equal to the $RMS$ velocity of $He$ gas at $27^{\circ} C$. The gas is