The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. If, at a total pressure of one standard atm. exerted by the vapours of water and toluene, the mole fraction of water Xw in the vapour phase satisfies

• A. 0 < Xw < 0.5
• B. Xw = 1.0
• C. Xw = 0.5
• D. 0.5 < Xw < 1.0

Answer: (D)