Q.
The pressure exerted by 1mol of CO2 at 273K is 34.98atm. Assuming that volume occupied by CO2 molecules is negligible, the value of van der Waals' constant for attraction of CO2 gas is
[P+V2a][V−b]=RT ∴[P+V2a]V=RT
Or V2P−RTV+a=0 V=2P+RT±R2T2−4Pa
Since, V is constant at given P and T,V can have only one value or discriminant =0 ∴R2T2=4 Paor a=4PR2T2 =4×34.98(0.821)2×(273)2 =3.59dm6atmmol−2