At a given temperature,the molar mass of gas $A$ is $4$. If it diffuses $3$ times faster than gas $B$,what is the molar mass of gas $B$?

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 .................. $cm^3$.

Equal masses of ethyne $(C_2H_2)$ and benzene $(C_6H_6)$ are taken in a flask at $400 \ K$. If the partial pressure of benzene is $600 \ torr$,what will be the total pressure of the gaseous mixture in $torr$?

The pressure of a moist gas at $27^{\circ}C$ is $4 \ atm$. The volume of the container is doubled at the same temperature. The new pressure of the moist gas is $x \times 10^{-1} \ atm$. Find the value of $x$. (Nearest integer) (Given: The vapour pressure of water at $27^{\circ}C$ is $0.4 \ atm$)

Explain the fire polishing of glass.

At the same temperature and pressure,the rate of diffusion of helium with respect to methane is ...... .