Explain the effect of the mass of a molecule on the Maxwell-Boltzmann speed distribution.

(N/A) According to the Maxwell-Boltzmann distribution,at a fixed temperature,the speed of gas molecules is inversely proportional to the square root of their molar mass $(u_{mp} = \sqrt{\frac{2RT}{M}})$.
Therefore,at a constant temperature,heavier molecules move more slowly than lighter molecules.
For example,the molar mass of $N_{2}$ is $28 \ g/mol$ and the molar mass of $Cl_{2}$ is $71 \ g/mol$.
Since the mass of $N_{2} <$ mass of $Cl_{2}$,the most probable speed $(u_{mp})$ of $N_{2}$ is greater than the most probable speed of $Cl_{2}$ at the same temperature.
$u_{mp}(N_{2}) > u_{mp}(Cl_{2})$ (at constant $T$)
The speed distribution curve for $N_{2}$ and $Cl_{2}$ is shown in the figure.