Which of the following statements about the composition of the vapour over an ideal 1 : 1 molar mixture of benzene and toluene is correct? Assume that the temperature is constant at 25^oC. (Given, vapour pressure data at 25^oC, benzene = 12.8 kPa, toluene = 3.85 kPa)

At 100^oC the vapour pressure of a solution of 6.5 g of a solute in 100 g water is 732 mm. If K_b = 0.52, the boiling point of this solution will be

Which of them is not equal to zero for an ideal solution?

Which one of the following electrolytes has the same value of van't Hoff factor (i) as that of Al₂(SO₄)₃ (if all are 100% ionised)?