Chemical Engineering Archives

7001. Inside the distillation column, the

Driving force for the vapour flow is the pressure drop

Liquids are not always at their bubble points

Pressure increases gradually from bottom to the top of the column

None of these

✅ The correct answer is option A.

7002. Flights in a rotary dryer are provided to

Lift and shower the solids thus exposing it thoroughly to the drying action of the gas

Reduce the residence time of solid

Increase the residence time of the solid

None of these

✅ The correct answer is option A.

7003. Molecular seives are regenerated by heating to __________ °C.

< 150

200-330

> 500

> 1000

✅ The correct answer is option B.

7004. At __________ reflux, theoretical number of plates in a distillation coloumn is calculated using Fenske-Underwood equation.

Operating

Total

Minimum

Maximum permissible

✅ The correct answer is option B.

7005. Separation of __________ employs gaseous diffusion process.

N₂ and O₂ from air

Isotopes of uranium

Isotopes of helium

SO₂ and air

✅ The correct answer is option B.

7006. The diffusivity (D) in a binary gas mixture is related to the temperature (T) as

D ∝ T

D ∝ T0.5

D ∝ T1.5

D ∝ T2

✅ The correct answer is option C.

7007. For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG:mass transfer co-efficient, mols/m² , a: in-terfacial area per unit volume of tower)

F/(FG.a)

FG/(G.a)

(G.a)/FG

L/(FG.G)

✅ The correct answer is option A.

7008. The McCabe Δ L law states that the

Molar heats of vaporisation of components are nearly equal

Linear crystal growth rate depends on the degree of supersaturation

Linear crystal growth rate does not depend on the crystal size

Linear crystal growth rate depends on the crystal size

✅ The correct answer is option C.

7009. If a two phase system is in physical equilibrium; then it means that, the

Escaping tendency of each component from the liquid phase to the vapor phase is exactly equal to that from vapor phase to liquid phase

Temperature of the liquid phase is equal to that of the vapor phase

Total pressure throughout the liquid phase is equal to that throughout the vapor phase

All of the above

✅ The correct answer is option D.

7010. As per Gilliland’s equation, the diffusivity is

Directly proportional to ‘T1.5’

Inversely proportional to ‘P’

Dependent on the molecular volume & molecular weight of components

All of the above

✅ The correct answer is option D.