Question

If $X$ is the total number of collisions which a gasmolecule register with others per unit time under particular conditions, then the collision frequency of the gas containing N molecules per unit volume is

• A. $X/N$
• B. $NX$
• C. $2NX$
• D. $NX/2$

Answer 1

Answer: (D)

$NX/2$

Answer 2

Number of collisions of one molecule/unit time $=X$
Number of collision of N molecules /unit time $=NX.$
As in one collision, two molecules are involved, collision frequency $=NX/2$