The vapour pressures of pure liquids A and B are 400 and 600 mm Hg, respectively, at 298 K. On mixing the two liquids, the sum of their initial volumes is equal to the volume of the final mixture. The mole fraction of liquid B is 0.5 in the mixture. The vapour pressure of the final solution, the mole fractions of components A and B in the vapour phase, respectively, are:

1. 500 mm Hg, 0.5, 0.5
2. 450 mm Hg, 0.5, 0.5
3. 500 mm Hg, 0.4, 0.6
4. 450 mm Hg, 0.4, 0.6

On mixing, heptane, and octane form an ideal solution at 373 K, the vapor pressures of the two liquid components (Heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressure of the solution obtained by mixing 25.0 g of heptane and 35 g of octane will be:
(molar mass of heptane = 100 g mol⁻¹ and of octane =114 g 1 mol⁻¹)

1. 144.5 kPa

2. 72.0 kPa

3. 36.1 kPa

4. 96.2 kPa

A binary liquid solution is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behavior of the solution?

1. The solution formed is an ideal solution

2. The solution is non-ideal, showing +ve deviation from Raoult’s Law

3. The solution is non-ideal, showing –ve deviation from Raoult’s Law

4. n-heptane shows +ve deviation while ethanol shows –ve deviation from Raoult’s Law.

Choose a false statement among the following:

In a mixture of A and B, components show negative deviations when: