Question

At what pressure does the mean free path of argon at 25°C become comparable to the size of a 2.4 dm³ vessel that contains it? Take σ = 0.36 nm².
The answer key is 0.034 Pa

Answer 1

z= collision frequency, c= mean speed, lambda= mean free path comparble to 2.4 dm= 0.24 m

or you can do reverse also, just put p= 0.034 Pa in the above equation you will get lambda= mean free path= 2.4 dm= 0.24m