If Kinetic Energy is directly proportional to mass, than the gas with the larger mass would have the larger kinetic energy, right? But what if the two separate gases are in two non-rigid containers of equal volume (1 Liter), and at the same temperature (25 celsius). The two gases are Carbon monoxide and carbon dioxide. There are 2 atm of carbon monoxide, and 1 atm of carbon dioxide. I used PV=nRT to find the moles of CO and CO2 using these conditions and concluded that there is more of Carbon monoxide than there is Carbon dioxide. Shouldn't this mean that it has more kinetic energy than carbon dioxide? Still, I also know that temperature is indicative of average kinetic energy, and so if they are both the same temperature than they should have the same kinetic energy. So I guess I was confused about which was right.