The critical pressure for real gases is given by

Options

A. `(8a)/(27 Rb)`
B. `(a)/(27 b^(2))`
C. `(2a)/(Rb)`
D. `3b`

Answer

B

Explanation

The minimum pressure required to cause the liquefaction of a gas at its critical temperature is called the critical pressure , `p_(c )`. It is given as
`p_(c ) = (a)/(27 b^(2))`
where `a` and `b` are van der Waals' gas constants.
Critical temperature `(T_(c )) = (8a)/(27 Rb)`
Critical volume `(V_(c )) = 3 b`
Inversion temperature `(T_(1)) = (2a)/(Rb)`