Engineering Questions with Answers - Multiple Choice Questions
Separation Processes MCQ’s – Binary Azeotropic Mixtures
1 - Question
What is the definition of azeotropic mixture?
a) A liquid mixture of two or more substances that boils at a constant characteristic temperature lower or higher than anyof its components and that retains the same composition in the vapor state as in the liquid state.
b) A liquid mixture of two or more substances that boils at a different characteristic temperature
c) A liquid mixture of two or more substances that boils at a constant characteristic pressure
d) A liquid mixture of two or more substances that boils at a constant characteristic temperature and pressure
View Answer
Answer: a
Explanation: A liquid mixture of two or more substances that boils at a constant characteristic temperature lower or higher than anyof its components and that retains the same composition in the vapor state as in the liquid state.
2 - Question
What is the value of K for azeotropic mixtures?
a) 0
b) 1
c) 2
d) 3
View Answer
Answer: b
Explanation: The vapor and liquid compositions are identical for azeotropic mixture; hence the K value is 1.
3 - Question
Isopropyl ether-isopropyl alcohol is which type of azeotropic mixture?
a) Minimum boiling heterogeneous mixture
b) Maximum boiling heterogeneous mixture
c) Minimum boiling homogeneous mixture
d) Minimum boiling heterogeneous mixture
View Answer
Answer: c
Explanation: Isopropyl ether-isopropyl alcohol is minimum boiling homogeneous mixture.
4 - Question
Which of the following is true?
a) Heterogeneous mixtures are minimum boiling point mixture
b) Homogeneous mixtures are minimum boiling point mixture
c) Heterogeneous mixtures are maximum boiling point mixture
d) Homogeneous mixtures are maximum boiling point mixture
View Answer
Answer: a
Explanation: Heterogeneous mixtures are minimum boiling point mixtures because activity coefficients should be significantly greater than 1
5 - Question
Which of the following is not true?
a) If more than one liquid phase exists,it is heterogenous azeotrope
b) A vapor can coexist with no more than two liquid phases
c) If the solution is layered then it is heterogeneous azeotrope
d) If one liquid phase exists it’s a homogeneous azeotrope
View Answer
Answer: c
Explanation: If the solution is layered then it is heterogeneous azeotrope is wrong and all other options are correct.
6 - Question
Which of the following is most common azeotrope?
a) Minimum boiling heterogeneous
b) Maximum boiling heterogeneous
c) Maximum boiling homogeneous
d) Minimum boiling homogeneous
View Answer
Answer: d
Explanation: Minimum boiling homogeneous azeotropes are most common. E.g.:- isopropyl ether-isopropyl alcohol.
7 - Question
What happens when activity coefficients are greater than 1?
a) The maximum total pressure is smaller than vapor pressure of either component
b) The maximum total pressure is greater than vapor pressure of either components
c) The maximum total pressure is greater than one component only
d) The minimum total pressure is greater than vapor pressure of either components
View Answer
Answer: The maximum total pressure is greater than vapor pressure of either component when the activity coefficients are greater than 1.
8 - Question
Where are maximum boiling homogeneous azeotropes approached in distillation?
a) Bottom product
b) Top product
c) Vapors
d) Separate channel required
View Answer
Answer: a
Explanation: The maximum boiling homogeneous azeotropes approached in distillation at the bottom product.
9 - Question
How is it possible to shift the equilibrium to advantage in azeotropic mixture?
a) Changing the volume
b) Adding more mixture
c) Adding one of the component more
d) Changing the pressure.
View Answer
Answer: d
Explanation: By changing the pressure it is possible to shift the equilibrium and “break” the azeotrope.
10 - Question
Which of the following could be an azeotropic mixture?
a) Components belonging to same functional group
b) Geometrical isomers
c) Functional isomers
d) Chain isomers
View Answer
Answer: c
Explanation: The functional isomers could have nearly same boiling points hence they could form an azeotropic mixture.