Mass Transfer

331.Molecular diffusivity of a liquid

1. Increases with temperature
2. Decreases with temperature
3. May increase or decrease with temperature
4. Is independent of temperature

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332.Molecular distillation is

1. High temperature distillation
2. For heat-sensitive materials
3. Very low pressure distillation
4. Both (B) and (C)

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333.Molecular sieves are porous

1. Alumina
2. Silica
3. Synthetic zeolites crystals/metal alumino-silicates
4. None of these

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334.Molecular sieves are regenerated by heating to _________ °C.

1. < 150
2. 200-330
3. > 500
4. > 1000

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335.Most important factor to be considered in the selection of packings for absorbers is the _________ of packing.

1. Size
2. Durability
3. Porosity
4. Cost

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336.Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure. Nitrobenzene will distil off _________ °C.

1. At < 100
2. At > 210.6
3. Between 100 and 210
4. None of these

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337.NSc/NPr is called the

1. Psychrometric ratio
2. Lewis number
3. Sherwood number
4. Stanton number

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338.Occurrence of 'case hardening' during drying of a high moisture solid cake _________ the drying rate.

1. Increases
2. Decreases
3. Does not affect
4. Exponentially increases

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339.On addition of solute in the solvent, the _________ of the solution decreases.

1. Boiling point
2. Freezing point
3. Vapour pressure
4. Both (B) and (C)

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340.On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in

1. Greater degree of separation with a fixed number of trays
2. Increased reboiler load
3. Increased reflux ratio
4. None of these

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