Related Mcqs:

1. The vapor pressures of benzene and toluene are 3 and 4/3 atmospheres respectively. A liquid feed of 0.4 moles of benzene and 0.6 moles of toluene is vaporised. Assuming that the products are in equilibrium, the vapor phase mole fraction of benzene is_________________?

   A. 0.4
   B. 0.6
   C. 0.8
   D. 0.2

2. Saturated solution of benzene in water is in equilibrium with a mixture of air and vapours of benzene and water at room temperature and pressure. Mole fraction of benzene in liquid is xB and the vapour pressures of benzene and water at these conditions are pv B and pv w respectively. The partial pressure of benzene in air-vapour mixture is_________________?

   A. PvB
   B. xB.PvB
   C. (Patm – Pvw)xB
   D. xB.Patm

3. 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. The temperature at which the above mixture will exert a pressure of one standard atm. is___________________?

   A. Less than 100°C
   B. 100°C
   C. Between 100 and 110°C
   D. 110.6°C

4. In a mixture of benzene vapor and nitrogen gas at a total pressure of 900 mm Hg, if the absolute humidity of benzene is 0.2 kg benzene/kg nitrogen, the partial pressure of benzene in mm Hg is__________________?

   A. 180
   B. 60.3
   C. 720
   D. 200

5. The ratio of existing moles of vapor per mole of vapor free gas to the moles of vapor that would be present per mole of vapor free gas, if the mixture were saturated at the existing temperature & pressure, is termed as the_____________________?

   A. Relative humidity
   B. Relative saturation
   C. Percentage saturation
   D. None of these

6. Assume that benzene is insoluble in water. The normal boiling points of benzene and water are 80.1 and 100°C respectively. At a pressure of 1 atm, the boiling point of a mixture of benzene and water is__________________?

   A. 80.1°C
   B. Less than 80.1°C
   C. 100°C
   D. Greater than 80.1°C but less than 100°C

7. At 100°C, water and methylcyclohexane both have vapour pressures of 1 atm. Also at 100°C, the latent heats of vaporisation of these compounds are 40.63 kJ/mole for water and 31.55 kJ/mole for methylcyclohexane. The vapour pressure of water at 150°C is 4.69 atm. At 150°C, the vapour pressure of methylcyclohexane would be expected to be_________________?

   A. Significantly less than 4.69 atm
   B. Nearly equal to 4.69 atm
   C. Significantly more than 4.69 atm
   D. Indeterminate due to lack of data

8. The vapor pressure of the solvent decreased by 10 mm Hg, when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent, if the decrease in vapor pressure of the solvent is required to be 20 mm Hg ?

   A. 0.2
   B. 0.1
   C. 0.4
   D. 0.6

9. Pure aniline is evaporating through a stagnant air film of 1 mm thickness at 300 K and a total pressure of 100 KPa. The vapor pressure of aniline at 300 K is 0.1 KPa. The total molar concentration under these conditions is 40.1 mole/m3. The diffusivity of aniline in air is 0.74 × 10-5m2/s. The numerical value of mass transfer co-efficient is 7.4 × 10-3. Its units are_______________________?

   A. m/s
   B. cm/s
   C. mole/m2.s.Pa
   D. k.mole/m2.s.Pa

10. A vapor whose partial pressure is less than its equilibrium vapor pressure is called a ______________ vapor?

    A. Saturated
    B. Supersaturated
    C. Superheated
    D. None of these