1. A mobile phase cannot be a :
a) Gas
b) Solid
c) Liquid
d) Solid or gas
Explanation: A mobile phase has to flow and hence it should not be a solid.
2. What is the representation of distribution coefficient?
a) S
b) H
c) G
d) K
Explanation: The distribution coefficient is denoted by K.
3. What is the colour post extraction of iodine?
a) Blue
b) Indigo
c) Purple
d) Red
Explanation: The colour after extracting iodine is purple.
4. The dispersed phase is also called as:
a) Non-continuous phase
b) Continuous phase
c) Dis-continuous phase
d) Gas phase
Explanation: The dispersed phase is also called as dis-continuous phase, the other phase being continuous phase.
5. What is true about mixer settlers?
a) Two liquid phases mixed with impellers and separated by gravity induced separation.
b) Two liquid phases unmixed, and magnetic separation carried out
c) Two liquid phases are mixed by impellers, and separated using magnetic separation
d) Two liquid phases are heated to mix, and gravity induced separation is carried out
Explanation:In mixer settlers, two liquid phases mixed with impellers and separated by gravity induced separation
6. The dispersed phase is:
a) Continuous
b) Heavier
c) Lighter
d) May be heavier or lighter
Explanation:The dispersed phase formed by mixing maybe a heavier or a lighter phase.
7. What is the major problem in settlers?
a) Colour of the two phases may be same
b) The two phases may not be visible
c) Emulsification in the mixing wheel
d) The size of dispersed particles can be large
Explanation:If the agitation is very intense, then the size of particles can reduce to 1 to 1.5 micrometers. Thus there could be emulsification, and it is problematic.
8. Which is the simple and the oldest technique for solvent extraction?
a) Spray column
b) Packed column
c) Plate column
d) Decanter
Explanation: Spray column is the simplest and oldest technique for solvent extraction.
9.Why are spray columns rarely used?
a) High cost
b) High efficiency
c) More size of equipment required
d) Due to axial dispersion
Explanation: Axial dispersion is so serious that with an increase in diameter-length ratio the continuous phase completely disperses
10. How does packing the column help?
a) Lessens the mass transfer
b) Increases the mass transfer by not breaking the large drops
c) Decreases the interfacial area
d) Increases the mass transfer by breaking the large droplets thus increasing interfacial area
Explanation:The packing columns minimize the axial dispersion and help by increasing the mass transfer by breaking the large droplets thus increasing interfacial area.