Engineering Questions with Answers - Multiple Choice Questions

# Separation Processes MCQ’s – The MSMPR Crystallization Model

1 - Question

In crystallization, solvent should dissolve large amount of solute at:
a) Room temperature
b) Boiling point
c) Freezing point
d) Slip melting point

Explanation: Solvent should dissolve large amount of solute at boiling point of solvent.

2 - Question

Insoluble impurities during crystallization are removed by:
a) Decantation
b) Filtration
c) Distillation
d) Fractional crystallization

Explanation: Since the impurities are insoluble they can be easily removed by filtration and no other methods are required

3 - Question

The crystals obtained in crystallization are dried by:
a) Dryer
b) Oven
c) Filter paper
d) Exposing to sun

Explanation: The moisture is sucked with the help of a filter paper and the crystals are dried.

4 - Question

Which of the following is not an assumption of MSMPR model?
a) Perfect mixing of the magma
b) No crystal breakage
d) Crystals are of various sizes.

Explanation: The crystals are assumed to be of same size in the MSMPR model.

5 - Question

What is the number of crystals per unit mass of crystals if
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 5
a) 0.01
b) 0.7
c) 0.6
d) 0.8

Explanation: Number of crystals per unit mass of crystals= 4.5/fvρL3, hence N=0.01.

6 - Question

What is the number of crystals per unit mass of crystals if
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.05
a) 0.01
b) 0.7
c) 0.6
d) 100000

Explanation: Number of crystals per unit mass of crystals= 4.5/fvρL3, hence N=1000000.

7 - Question

What is the number of crystals per unit mass of crystals if
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.78
a) 1.56
b) 2.34
c) 2.56
d) 0.8

Explanation: Number of crystals per unit mass of crystals= 4.5/fvρL3, hence N=2.56.

8 - Question

What is the number of crystals per unit mass of crystals if
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.56
a) 5.67
b) 6.78
c) 7.11
d) 9.56

Explanation: Number of crystals per unit mass of crystals= 4.5/fvρL3, hence N=7.11.

9 - Question

What is the number of crystals per unit mass of crystals if
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.67
a) 1.56
b) 7.89
c) 4.22
d) 4.15

Explanation: Number of crystals per unit mass of crystals= 4.5/fvρL3, hence N=4.15.

10 - Question

What is the nucleation rate if
Mass of production of crystals C=0.5kg
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.5
volume of mother liquor in magma V= 1m3
a) 0.5
b) 1.5
c) 1.8
d) 2.7

Explanation: The nucleation rate=4.5C/fvρL3V, hence rate= 1.8.

11 - Question

What is the nucleation rate if
Mass of production of crystals C=0.5kg
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.5
volume of mother liquor in magma V= 0.5m3
a) 5.4
b) 3.6
c) 1.8
d) 2.7

Explanation: The nucleation rate=4.5C/fvρL3V, hence rate= 3.6.

12 - Question

What is the nucleation rate if
Mass of production of crystals C=0.5kg
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.6
volume of mother liquor in magma V= 1m3
a) 1.45
b) 1.5
c) 1.07
d) 1.04

Explanation: The nucleation rate=4.5C/fvρL3V, hence rate= 1.04.

13 - Question

What is the nucleation rate if
Mass of production of crystals C=0.5kg
Volume shape factor fv= 0.5
Density of particle= 0.5kg/m3
Characteristic size of crystal L= 0.5
volume of mother liquor in magma V= 1m3
a) 0.5
b) 15
c) 1.8
d) 18

Explanation: The nucleation rate=4.5C/fvρL3V, hence rate= 18.

14 - Question

What is the nucleation rate if
Mass of production of crystals C=10kg
Volume shape factor fv= 0.5
Density of particle= 5kg/m3
Characteristic size of crystal L= 0.5
volume of mother liquor in magma V= 1m3
a) 9
b) 18
c) 180
d) 36