For one mole of a vander Waals’ gas when b = 0 and T = 300 K, the PV vs. 1/V plot is shown below. The value of the van der Waals’ constant a (atm L mol–2)

The Vander waals equation can be written as- 2 2 ( / )( ) P n a V V nb nRT 2 2 2 1 2 1 ( / )( ) , 0 / / / / 1.5 20.1 21.6 3 2 P n a V V nb nRT given b PV a V RT PV RT a V Slope y y x x