Engineering Questions with Answers - Multiple Choice Questions

# Separation Processes MCQ’s – Melt Crystallization

1 - Question

What is the definition of melt crystallization?
a) Crystallization of melts from eutectic-forming or solid solution forming mixtures
b) Crystallization of melts from eutectic-forming or liquid solution forming mixtures
c) Crystallization of melts from eutectic-forming or constant boiling mixtures
d) Crystallization at very high temperatures

Explanation: Crystallization of melts from eutectic-forming or solid solution forming mixtures is called as melt crystallization.

2 - Question

What are the two major methods for melt crystallization?
a) Suspension, layer
b) Layer, multilayer
c) Suspension, colloidal
d) Layer, non-layer

Explanation: The two types of melt crystallization are suspension crystallization and melt crystallization.

3 - Question

If Kc=10
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=2
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 20
b) 22.4
c) 25.6
d) 27.8

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 22.4.

4 - Question

If Kc=10
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=4
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 14.6
b) 15.63
c) 15.81
d) 27.2

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 15.81.

5 - Question

If Kc=10
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=2
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 12.9
b) 15.7
c) 19.5
d) 27.8

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 12.9.

6 - Question

If Kc=20
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=2
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 25.6
b) 29.4
c) 31.6
d) 72.5

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 31.6.

7 - Question

If Kc=30
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=2
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 31.6
b) 34.6
c) 36.7
d) 38.7

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 38.7.

8 - Question

If Kc=20
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=4
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 20
b) 22.4
c) 25.6
d) 27.8

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 22.4.

9 - Question

If Kc=40
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=2
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 34.6
b) 39.6
c) 44.7
d) 78.4

Explanation: Since crystal thickness= sqrt(2*( Tm-Tc)Kct/dH), hence crystal thickness= 44.7.

10 - Question

If Kc=30
Temperature difference Tm-Tc=50
Time taken = 3000s
Density d=4
Rate of heat released by freezing =1000
Calculate the crystal thickness
a) 20
b) 22.4
c) 25.6
d) 27.38