A. High temperature distillation
B. For heat-sensitive materials
C. Very low pressure distillation
D. Both B. and C.
Related Mcqs:
- When the feed to a distillation column is a saturated liquid, slope of the feed line is_____________________?
A. Zero
B. Unity
C. Infinity
D. None of these - In extractive distillation, solvent is_____________________?
A. Added to alter the relative volatility of the mixture
B. Of high volatility
C. Present in overhead stream
D. Of high viscosity to give high tray efficiency - Polar organic compounds are normally used as separating agents for the azeotropic and extractive distillation. Which of the following is the most important factor to be considered for the choice of the separating agent for extractive distillation ?
A. Cost
B. Availability
C. Toxicity
D. Selectivity - Pore size of the molecular sieve 5A is ____________________ mm ?
A. 5
B. 0.5
C. 0.05
D. 50 - The value of NA/(NA + NB) for steady state molecular diffusion of gas ‘A’ through nondiffusing gas ‘B’ is____________________?
A. 1
B. ∞
C. 0.5
D. 2 - Molecular diffusivity of a liquid__________________?
A. Increases with temperature
B. Decreases with temperature
C. May increase or decrease with temperature
D. Is independent of temperature - According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity) ?
A. D
B. D2
C. D0.5
D. 1/D - Component A is diffusing in a medium B. The flux NA relative to a stationary point is equal to the flux due to molecular diffusion, if____________________?
A. Mass transfer is accompanied by reaction
B. Diffusion of A is in stagnant medium B
C. Molecular mean free path is high
D. There is equimolar counter diffusion - JD factor for mass transfer is a function of Reynolds number. Mass transfer by molecular diffusion from a single drop to surrounding still air is given by___________________?
A. Nsh = 2
B. Nst = 2
C. Nsc = 2
D. None of these - Molecular diffusion is caused by the________________?
A. Transfer of molecules from low concentration to high concentration region
B. Thermal energy of the molecules
C. Activation energy of the molecules
D. Potential energy of the molecules
