What is the $rms$ velocity of $O_2$ at $STP$ (in $cm/s$)?

Let $(C_{rms})_{H_2}$ be the r.m.s. speed of $H_2$ at $150 \ K$. At what temperature will the most probable speed of helium $[(C_{mp})_{He}]$ be half of $(C_{rms})_{H_2}$ (in $K$)?

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)

Amongst the following, which should have the highest $rms$ speed at the same temperature?

The ratio of most probable velocity to that of average velocity is

When the temperature of a gas is increased from $30^{\circ} C$ to $930^{\circ} C$,the root mean square speed of the gas would