The two liquids ‘A’ and ‘B’ have the same molecular mass and form ideal solution. The solution has the vapour pressure 700 mm at ${80}^{0}C.$ The above solution is distilled without reflux. Three-fourth of the solution is collected as condensate. The mole fraction of ‘A’ in the condensate is 0.75 and that in the residue is 0.3. The vapour pressure of the residue at ${80}^{0}C$ is 600 mm.