Helium diffuses four times faster than which of the following?

If the most probable speed of methane $(CH_4)$ at a certain temperature is $400 \ ms^{-1}$,what is the kinetic energy of one mole of methane at the same temperature in $J$?

At $600 \ K$,the root mean square (rms) speed of gas $X$ (molar mass $= 40 \ g \ mol^{-1}$) is equal to the most probable speed of gas $Y$ at $90 \ K$. The molar mass of the gas $Y$ is $....... \ g \ mol^{-1}$. (Nearest integer)

If the $RMS$ velocity of an ideal gas is $v \ ms^{-1}$ at $127^{\circ} C$,at what temperature its $RMS$ velocity is doubled (in $K$)?

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

The given figure shows the Maxwell distribution of molecular speeds of a gas at three different temperatures $T_1$,$T_2$ and $T_3$. The correct order of temperature is