The term that is correct for the attractive forces present in a real gas in the van der Waals equation is

Options

A. `-nb`
B. `-(an^(2))/(V^(2))`
C. `(an^(2))/(V^(2))`
D. `nb`

Answer

C

Explanation

The total force of attraction on any molecule about to hit wall is proportional to the concentration of the neighboring molecules , `n//V` . However , the number of molecules about to hit the wall per unit wall area is also proportional to the concentration , `n//V`. Therefore , the force per unit wall area (pressure) is reduced from that assumed in the ideal gas law by a factor proportional to `n^(2)//V^(2)`. Letting `a` to be the proportionality constant, we can write the correction factor as
`an^(2)//V^(2)`