Question

Calculate the mean free path of gas molecules, if number of molecules per `cm^(3) is 3 xx 10^(19)` and diameter of each "molecule" is `2Å`.

Answer 1

Correct Answer - `1.876 xx 10^(-7) m`.
Here, `lambda = ?, n=3 xx 10^(19)//cm^(3) = 3 xx 10^(250//m^(3)`
`d=2Å = 2 xx 10^(-10) m`
As. `lambda = (1)/(sqrt(2)pi d^(2)n)`
`:. Lambda = (1)/(1.414 xx 3.14 (2xx10^(-10))^(2) xx 3 xx 10^(25))`
`=(100 xx 10^(-7))/(1.414 xx 3.14 xx 4 xx 3)`
`=1.876 xx 10^(-7) m`.