Question

The ratio of no of collisions per second at the walls of container by He and O2 gas molecules kept at same volume and temperature is ?

Answer 1

First we will define Collision Frequency, it is defined as the number of collisions which take place in 1 second among the molecules present in 1 cc of the gas. 

Also collision number (Nc) is the number of collisions which a single molecule undergoes with other molecules in 1 second. 

So Nc = 2πvo2 n 

Where v  = average speed  

O = molecular diameter 

N = number of molecules  

Collisions among molecules will be Nc * n 

Each collision requires 2 molecules, collision frequency  

Z = (Nc * n) / 2 = (½) * πvo2 n2  

Average speed (v) = sqrt(8RT/(πM)) where M is the molecular mass 

Hence, 

Z = 2o2n2 sqrt(πRTM) 

This is the required formula for this question 

We know that M for 02 molecule is 32u and for Helium molecule is 4u 

Hence z1/z2 = ratio of He to that of Oxygen = (const/sqrt4) * (sqrt32/const) 

= sqrt(8/1) 

= 2 2 :1

Answer 2

Answer:

2√2:1

Explanation:

No.of collision is inversely proportional to√ molecular mass