Question

Ultra-high-vacuum experiments are routinely performed at a total pressure of 1.0x10-10 Torr.

Estimate (1) the number of collisions of a N2 molecule per second,

(2) the average distance traveled by a N2 molecule between successive collisions at 350 K under these conditions. The collision diameter of N2 is 3.75Ã .

(3) Describe how the result would affect the diffusion rate under such condition compared to that at ambient pressure, where a molecule collides 7.5x109 times per second, and travels 640Ã between collisions on average.