Question #396f4

1 Answer

Helium will have the higher velocity given that both gases are at the same temperature.


If both gases are at the same temperature, their kinetic energy (KE) values will be equal to each other.

KE = #1/2 mv^2#

Since the mass of He is 4g/mol and #CO_2# is 44g/mol the He atoms must be moving much faster than the #CO_2# molecules since their mass is so much lower.

You can calculate how much faster He atoms will move by using Graham's law. Here is a video discussing how to use this law. The sample uses He and #N_2#, to solve for your question you would just substitute in the #CO_2# value instead of nitrogen then re-calculate.

Hope this helps!