If the rate of diffusion of gas $A$ is five times that of gas $B$,what will be the ratio of the densities of $A$ and $B$?

The $O_2$ gas is collected over water at $400 \ K$ temperature in a $2 \ L$ vessel. If the total pressure of the mixture is $33.26 \ bar$ and the pressure of dry $O_2$ gas is $32.20 \ bar$,find the vapour pressure of water under the same conditions.

At higher altitudes,the boiling point of water lowers because:

Intermolecular forces and thermal energy decide the physical state of matter. Explain.

$A$ certain gas takes three times as long to effuse out as helium. Its molecular mass will be ........... $u$.

Gaseous state is characterised by which of the following physical properties?
$I$. Gases mix evenly and completely in all proportions without any mechanical aid.
$II$. Gases exert pressure in all directions evenly.
$III$. Gases are highly compressible and have lower density than liquids and solids.
$IV$. The volume and shape of the gas is fixed.