Molecular Properties of Gases

Stuck on a problem! Get one on one Homework Help from our Expert Tutors

Physics Fluid Mechanics and Thermal Physics

	The mean free path:
	The mean free path of a particle is the average distance covered by a particle between subsequent impacts. If the molecules have diameter d, then the effective cross-section for the collision can be modeled by using a circle of diameter 2d to represent a molecule’s effective collision area while treating the target molecules as point masses. Now, the circle would sweep out the volume within time t and the number of collisions can be estimated from the number of gas molecules that were in that volume. Then the mean free path is the length of the path divided by the number of collisions. The length of the path is given as: If the number of molecules per unit volume = n_vv and volume of interaction = πd²vt, then the mean free path can be estimated as: