The gas that has the slowest rate of diffusion among $O_2$,$H_2$,$CO_2$ and $CH_4$ is

The average velocity of gas molecules is equal to ...... .

If a gas contains only three molecules that move with velocities of $100, 200, 500 \ ms^{-1}$. What is the rms velocity of that gas in $ms^{-1}$?

The ratio between the root mean square velocity of $H_2$ at $50 \ K$ and that of $O_2$ at $800 \ K$ is

If the kinetic energy and $RMS$ speed of a gas at a certain temperature are $4.0 \ kJ \ mol^{-1}$ and $5.0 \times 10^4 \ cm \ s^{-1}$,respectively,the molecular weight of the gas is:

The most probable velocity is given by .......