The vapour pressure of a dilute aqueous solution of glucose is 750 mm of Hg at 373 K. The mole fraction of solute in the solution is-
1. 1/10
2. 1/76
3. 1/7.6
4. 1/35

Mole fraction of the component A in vapour phase is X₁ and mole fraction of component A in liquid mixture is X₂ then 

(${\mathrm{P}}_{\mathrm{A}}^0$ = vapour pressure of pure A; ${\mathrm{P}}_{\mathrm{B}}^0$= vapour pressure of pure B),

then total vapour pressure of the liquid mixture is-

1. $\frac{{\mathrm{P}}_{\mathrm{A}}^0{\mathrm{X}}_2}{{\mathrm{X}}_1}$

2. $\frac{{\mathrm{P}}_{\mathrm{A}}^0{\mathrm{X}}_1}{{\mathrm{X}}_2}$

3. $\frac{{\mathrm{P}}_{\mathrm{B}}^0{\mathrm{X}}_1}{{\mathrm{X}}_2}$

4. $\frac{{\mathrm{P}}_{\mathrm{B}}^0{\mathrm{X}}_2}{{\mathrm{X}}_1}$

The vapour pressure of pure water at 298K is 23.76mm. The vapour pressure of a solution of sucrose(C₁₂H₂₂O₁₁) in 5.56 moles of water is 23.392mm Hg. The mass of sucrose in the solution is

1. 15 g

2. 45 g

3. 30 g

4. 37.5 g

The vapour pressure of a pure liquid solvent A is 0.80 atm. When a non-volatile substance B is added to the solvent, its vapour pressure drops to 0.60 atm.
Mole fraction of the component B in the solution is:

The relative lowering of vapour caused by dissolving 71.3 g of a substance in 1000 g of water is 7.13 x 10^-3. The molecular mass of the substance is-

1. 180 g mol^-1

2. 18 g mol^-1

3. 1.8 g mol^-1

4. 360 g mol^-1