Molecules of benzoic acid (C6H5COOH) dimerise in benzene. 'w' g of the acid dissolved in 30 g of benzene shows a depression in freezing point equal to 2 K. If the percentage association of the acid to form dimer in the solution is 80, then w is : (Given that Kf = 5 K kg mol–1, Molar mass of benzoic acid = 122 g mol–1)
(1) 1.5 g
(2) 2.4 g
(3) 1.8 g
(4) 1.0 g
