Question

3.9 g of benzoic acid dissolved in 49 g of benzene shows a depression in freezing point of 1.62 K. Calculate the Van't Hoff factor and predict the nature of solute (associated or dissociated). 

(Given : Molar mass of benzoic acid = 122 g mol^-1, K_f for benzene = 4.9 K kg mol^-1)

Answer 1

△T_f = iK_fm

.^. .   i = 0.50

As the value of i < 1,the solute is associated.