Assuming that the behaviour of ammonia is correctly described by the van der Waal's equation near the critical point, and knowing the critical molar volume of `0.72500 mol L^(-1)` and critical temperature of 405.3 K, determine the critical pressure of ammonia.

Options

A. 109.8 atm
B. 141.3 atm
C. 152.6 atm
D. 17.20 atm

Answer

D

Explanation

`because V_(e) = 3b ` and `T_(e) = (8a)/(27Rb) , (T_(e))/(V_(e)) = (8a)/(27 Rb) xx (1)/(3b) = ((a)/(27 b^(3))) ((8)/(3R)) = p_(e) ((8)/(3R))`
`p_(e) = ((3R)/(8)) ((T_(e))/(V_(e))) = (3 xx 0.082 )/(8) xx (405.3)/(0.725) = 17.2` atm
would have `(n_(2))/(n_(1)) = (1499)/(1212.8) = (1.236)/(1)`