[Physics] Dependence of average speed of molecules of gaseous mixture


We know that the average speed of gases in a single gas chamber is given by $\sqrt{8RT/\pi M}$

where R is universal gas constant,T is temperature,M is molar mass of gas.

But what if we mix two gases in any ratio say 1:1 and then try to find average speed of anyone of the gases.

Will the both gases have have same average speed or different?If same ,how will it be calculated and if different will it be given by same above formula?

Best Answer

If the two gasses are mixed then they will reach the same temperature, with the lighter molecules moving faster than heavier ones.

In the initial equation, 8, R, T and pi would all be the same. Since the gas molecules have different masses the speeds must therefore be different.

If a tank hits my car side on, my car goes flying. If my car hits a tank side on, the tank hardly moves. Its high mass causes its velocity to change little. So it's normal that the lighter molecules get banged around faster when gasses are mixed.