An ideal solution is prepared by mixing two liquids A (molar mass = 100 g/mol and density = 1.25 g/ml) and B (molar mass = 50 g/mol and density = 1.0 g/ml) The molal volume of liquid ‘A’ increases by a factor of 3800 as it vaporizes at ${27}^{\circ }C$  and that of liquid ‘B’ increases by a factor of 7600 at ${27}^{\circ }C$. A solution of liquids ‘A’ and ‘B’ at ${27}^{\circ }C$  has a vapour pressure of 54.0 torr.  (R = 0.08 L-atm/K-mol).