At constant volume and temperature conditions,the rate of diffusion $D_A$ and $D_B$ of gases $A$ and $B$ having densities $\rho_A$ and $\rho_B$ are related by the expression:

The density of a gas at $STP$ is $2.86 \, g \, L^{-1}$. Which gas is it?

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 $B$?

On what factors does the vapor pressure of a liquid depend?

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.

Fill in the blanks:
$(1)$ The temperature at which gases possess zero volume is called ........... .
$(2)$ In a mixture of gases,the pressure exerted by each individual gas is called .......... .
$(3)$ The pressure exerted by water vapor is known as ..... .
$(4)$ Thermal energy is directly proportional to the ..... of the substance.