# Imagine that hydrogen molecules (H_2) and oxygen molecules (O_2) decided to have a race. if the temperature was the same for both gases, which gas would win the race? Why?

Jul 28, 2017

What are the odds....? I would put my money on the dihydrogen molecule.

#### Explanation:

The dihydrogen molecule should win the face handily.

Kinetic molecular theory establishes that the root mean square velocity of a gaseous particle is given by.....

v_"rms"=sqrt((3RT)/(M_"gas"))

And since ${v}_{\text{rms}}$ is inversely proportional to the square root of the mass of the molecule given equivalent temperature, dihydrogen is faster.

Note that this principle can be exploited practically in the separation of isotopic gases, according to their differential speeds.