The commonly used solvent in supercritical extraction is_____________________?

Related Mcqs:

1. 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

2. 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%

3. Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when____________________?

   A. Extracting solvent is cheaply & abundantly available
   B. One of the liquid components is heat sensitive
   C. Viscosity of liquid components is very high
   D. One of the liquid components has very high affinity towards the solvent

4. Selectivity of the solvent used in solvent extraction should be)_________________?

   A. 1
   B. > 1
   C. < 1
   D. 0

5. Degree of freedom for leaching and solvent extraction process is_____________________?

   A. 0
   B. 1
   C. 2
   D. 3

6. With increase in temperature, the rate of extraction in leaching (solid-liquid extraction system) ?

   A. Increases
   B. Decreases
   C. Remain unaffected
   D. Increases Linearly

7. Extraction of penicillin employs a ________________ extraction column?

   A. Centrifugal
   B. Packed
   C. Plate
   D. None of these

8. Perforated plate towers are unique for solvent extraction because, they provide_____________________?

   A. Higher contact area
   B. Better contact of the phase
   C. Repeated coalescence & redispersion of the drop phase
   D. None of these

9. 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

10. The solvent used in liquid-liquid extraction should have _______________ less than one?

    A. Selectivity
    B. Distribution co-efficient
    C. Both A. and B.
    D. Neither A. nor B.