At the same temperature and pressure,the rate of diffusion of gas $X$ is $3 \sqrt{3}$ times that of a gaseous hydrocarbon of molar mass $54 \ g \ mol^{-1}$. The molar mass of $X$ in $g \ mol^{-1}$ is

$A$ bulb contains $1 \ g$ of $H_2$ and $1 \ g$ of $He$. If the total pressure is $1.2 \times 10^3 \ Pa$,then the partial pressure of $He$ is ............. $Pa$.

$50 \ mL$ of hydrogen gas diffuses through a small hole in a container in $20 \ min$. How much time (in $min$) will $40 \ mL$ of oxygen take to diffuse under the same conditions?

Under similar conditions of temperature and pressure,$50 \ mL$ of gas $A$ diffuses through a hole in the same time that $40 \ mL$ of gas $B$ diffuses. If the molar mass of gas $A$ is $64$,what is the molar mass of gas $B$?

Where will the boiling point be lower: at the seashore or on a mountain? Why?

The rate of diffusion of two gases $x$ and $y$ is $10 \ mL/sec$ and $40 \ mL/sec$ respectively. The ratio of their molar masses $(Mw)_{x} : (Mw)_{y}$ is: