Which of the following assumes constant molal vaporisation and overflow ?

Related Mcqs:

1. During constant rate drying period, vaporisation rate per unit drying surface area _____________________?

   A. Decreases with time
   B. Increases with time
   C. Does not change with time
   D. Does not affect the moisture content of the wet solid

2. Unit of molal diffusivity is____________________?

   A. cm2/sec gm . mole
   B. gm moles/cm2 . sec
   C. gm moles/cm. sec
   D. gm moles/cm2. sec

3. In case of non-ideal gases and liquids, the molal diffusivity ________________?

   A. Varies inversely as the pressure
   B. Varies directly as the pressure
   C. Is independent of pressure
   D. Is equal to the volumetric diffusivity

4. If xD = overhead product molal composition and RD = reflux ratio, then slope and intercept of the operating line for rectifying section are respectively ?

   A. [xD/(RD + 1)], [RD/(RD + 1)]
   B. [RD/(RD + 1)], [xD/(xD + 1)]
   C. [xD/(RD + 1)], [(RD + 1)/RD]
   D. None of these

5. Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of _______________ humidity?

   A. Molal
   B. Relative
   C. Percentage
   D. None of these

6. Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of _______________ humidity?

   A. Molal
   B. Relative
   C. Percentage
   D. None of these

7. The solvent used in liquid extraction should not have high latent heat of vaporisation, because ______________________?

   A. The pressure drop and hence the pumping cost will be very high
   B. It cannot be recovered by distillation
   C. Its recovery cost by distillation may be prohibitively high
   D. It will decompose while recovering by distillation

8. Heat sensitive materials with very high latent heat of vaporisation may be economically separated using__________________?

   A. Liquid extraction
   B. Distillation
   C. Evaporation
   D. Absorption

9. A 25 cm × 25 cm × 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m × 1m × 1cm flat sheet of the same material is to be dried from one side only. Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is ____________________?

   A. 1000
   B. 1500
   C. 2000
   D. 2500

10. During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the _________________ remains constant ?

    A. Wet bulb temperature
    B. Partial pressure of water vapor
    C. Relative humidity
    D. None of these