© Copyright, Department of Physics, University of Illinois at Urbana-Champaign

Diatomic Equipartition

A container of gas molecules is at a pressure of 2 atm and has a mass density of 1.7 grams per liter. All of the molecules in the container are diatomic nitrogen molecules with an atomic weight of 28 grams per mole. What is the average speed of the nitrogen molecules in the container? Here we define the average speed as the root-mean-square velocity (RMS velocity = vrms) of the center of mass of the molecule.

vrms = m/s