A. Changes the relative volatility of the original components
B. Should be of high volatility
C. Should form azeotropes with the original components
D. All A., B. and C.
Related Mcqs:
- 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 - In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas solute C is soluble in both the solvents. The extraction process attains equilibrium. The equilibrium relationship between the two phases is Y* = 0.9X, where Y* is the kg of C/kg of B and X is kg of C/kg of A. Choose the correct answer?
A. The entire amount of C is transferred to solvent B
B. Less than 2 kg but more than 1 kg of C is transferred to solvent B
C. Less than 1 kg of C is transferred to B
D. No amount of C is transferred to B - Solvent used in extractive distillation_________________________?
A. Is of low volatility
B. Forms a low boiling azeotrope
C. Forms a high boiling azeotrope
D. Does not alter the relative volatility of the original components - 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 - Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m2 and the solvent flow, rate is 400 moles of S/m2. hr. The equilibrium data is represented by Y = 3X2 , where Y is in moles of a A/moles of B and X is in moles A/moles of S. The maximum percentage extraction achieved in the unit is_________________________?
A. 25%
B. 50%
C. 70%
D. 90% - Selectivity of the solvent used in solvent extraction should be)_________________?
A. 1
B. > 1
C. < 1
D. 0 - 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 - Molarity is defined as the number of gm moles of solute per ________________ of solvent?
A. Litre
B. kg
C. gm
D. c.c - In a solution containing 0.30 Kg mole of solute and 600 kg of solvent, the molality is_______________________?
A. 0.50
B. 0.60
C. 1
D. 2 - With increase in solvent rate, the number of transfer units, NtoG, for a fixed degree of absorption from a fixed amount of gas________________?
A. Increases
B. Decreases
C. Decreases linearly
D. Remain unaffected
