Question

By doing a literature search, state the approximate number of collisions that a perfect gas molecule (e.g. N2) makes at room temperature and at 1 atm pressure in 1 second (you do not need to calculate this value). What is the significance of this value in the experiment of diffusion of gases( the purpose of the experiment is to measure rates of diffusion of two gases through the air as an experimental test of Graham`s law)?

Answer 1

Part1:

Number of collision or collisional frequency, in which two molecules collide for a given system and average number of collision could be expressed in per unit of time.

there is few assumption could be made for deriving and calculating the collisional frequency.

1) All molecules travel through space in straight lines

2) all molecules are hard, solid sphere

3) the reactions of interest is between only two molecules

4) collisions are hit and miss only

Now in determining the collisional frequency for a single molecule, Zi for consideration a jar filled with N2 atoms. these atoms collide, if every atom except one is frozen and the number of collision in one min. is counted, will be

the collisional frequency Zi = (Volume of collisional Cylinder * Density) / Time

now the volume of collisional cylinder =  

next, Density

now combining both the equation for the full equation: Zi =

now if we will consider all molecule moving then collision for every atom of Nitrogen within the jar in a minute are counted, Zii results

thus Z_ii =

this expands to Zii =

Part B: Plz refer image