Question

For two different gases at the same temperature, the gas with the lighter molecules (lower molecular mass) will have, on average:

Q: Answer-For two different gases at the same temperature, the gas with the lighter molecules (lower molecular...

In kinetic theory of gases, the average kinetic energy of a gas molecule depends only on temperature and is independent of the type of gas. The formula for average kinetic energy per molecule is where m mass of one molecule M molar mass From this, we can see Smaller the mass lighter molecule higher the rms speed. Heavier molecule lower the rms speed. Thus, for a lighter gas at same temperature It has the same average kinetic energy as heavier gas. But it has higher average speed.