$50 \ mL$ 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?

$A$ gaseous mixture of $2$ moles of $A$, $3$ moles of $B$, $5$ moles of $C$, and $10$ moles of $D$ is contained in a vessel. Assuming that gases are ideal and the partial pressure of $C$ is $1.5 \ atm$, what is the total pressure (in $atm$)?

If a gas diffuses $1/5$ times as fast as hydrogen,its molar mass will be....

$A$ gas diffuses $1/3$ times as fast as hydrogen. Its molecular weight is

Define surface tension and provide its dimensions and $SI$ unit.

At $100\,^oC$ and $1\, atm$ pressure,the density of liquid water is $1.0\, g\, cm^{-3}$ and the density of water vapor is $0.0006\, g\, cm^{-3}$. What is the volume occupied by water molecules in $1\, L$ of steam at the same temperature in $cm^3$?