Which of the following sets consists of gases with the same rate of diffusion?

At ${100\,^o}C$ and $1\ L$,if the density of liquid water is $1.0\ g\ cm^{-3}$ and that of water vapour is $0.0006\ g\ cm^{-3}$,then the volume occupied by water molecules in $1\ L$ of steam at that temperature is .................. $cm^3$.

$A$ mixture of equal masses of $SO_2$,$CH_4$,and $O_2$ is taken in an empty container at $298 \, K$. If the total pressure is $2.1 \, atm$,the partial pressure of $CH_4$ in the mixture will be .......... $atm$.

Which of the following gas mixtures is not applicable for Dalton's law of partial pressure?

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

When a sample of gas is compressed at constant temperature from $15 \, atm$ to $60 \, atm$,its volume changes from $76 \, cm^3$ to $20.5 \, cm^3$. Which of the following statements are possible explanations of this behaviour?
$(1)$ The gas behaves non-ideally
$(2)$ The gas dimerises
$(3)$ The gas is adsorbed into the vessel walls