1. What is the primary purpose of distillation?
o A) To separate components based on their boiling points
o B) To mix components
o C) To react components chemically
o D) To filter out solids
o Correct Answer: A
2. Which of the following is a common type of distillation?
o A) Simple distillation
o B) Complex distillation
o C) Advanced distillation
o D) All of the above
o Correct Answer: A
3. In which industries is distillation commonly used?
o A) Chemical industry
o B) Petroleum industry
o C) Alcoholic beverage industry
o D) All of the above
o Correct Answer: D
4. Distillation relies on the difference in which physical property of the components?
o A) Density
o B) Boiling point
o C) Melting point
o D) Color
o Correct Answer: B
5. During distillation, the component with the lower boiling point will:
o A) Condense first
o B) Evaporate first
o C) Remain in the liquid phase
o D) Mix with other components
o Correct Answer: B
6. What is the term for the liquid collected after condensation during distillation?
o A) Residue
o B) Distillate
o C) Precipitate
o D) Solute
o Correct Answer: B
7. Which type of distillation is used for separating components with very close boiling points?
o A) Simple distillation
o B) Fractional distillation
o C) Steam distillation
o D) Vacuum distillation
o Correct Answer: B
8. Which type of distillation involves the use of a vacuum to lower boiling points?
o A) Simple distillation
o B) Fractional distillation
o C) Steam distillation
o D) Vacuum distillation
o Correct Answer: D
9. Steam distillation is particularly useful for:
o A) High boiling point substances
o B) Temperature-sensitive compounds
o C) Salts
o D) Metals
o Correct Answer: B
10. Which piece of equipment is essential for fractional distillation?
o A) Liebig condenser
o B) Fractionating column
o C) Rotary evaporator
o D) Separatory funnel
o Correct Answer: B
11. What is the function of a condenser in a distillation setup?
o A) To heat the mixture
o B) To provide insulation
o C) To cool and condense the vapor
o D) To measure temperature
o Correct Answer: C
12. In a simple distillation setup, the distillation flask is connected to:
o A) A cooling jacket
o B) A condenser
o C) A heating mantle
o D) A fractionating column
o Correct Answer: B
13. The efficiency of a distillation column is often measured in terms of:
o A) Reflux ratio
o B) Theoretical plates
o C) Boiling point difference
o D) Distillation rate
o Correct Answer: B
14. Increasing the number of theoretical plates in a distillation column will:
o A) Decrease the separation efficiency
o B) Increase the separation efficiency
o C) Have no effect on separation efficiency
o D) Decrease the reflux ratio
o Correct Answer: B
15. A higher reflux ratio in a distillation process typically results in:
o A) Lower purity of distillate
o B) Higher purity of distillate
o C) Faster distillation process
o D) More theoretical plates required
o Correct Answer: B
16. A distillation curve represents:
o A) The melting point of components
o B) The boiling point of components over time
o C) The cooling rate of components
o D) The viscosity of the components
o Correct Answer: B
17. In a boiling point diagram for a binary mixture, the azeotrope is the point where:
o A) The boiling points of both components are the same
o B) The composition of liquid and vapor phases are the same
o C) One component is completely distilled
o D) Both components condense simultaneously
o Correct Answer: B
18. The presence of an azeotrope in a mixture:
o A) Simplifies the distillation process
o B) Complicates the distillation process
o C) Has no effect on the distillation process
o D) Makes distillation impossible
o Correct Answer: B
19. Fractional distillation is primarily used in the petroleum industry to:
o A) Separate crude oil into its components
o B) Produce chemical reactions
o C) Mix different fuels
o D) Filter impurities from oil
o Correct Answer: A
20. In the alcoholic beverage industry, distillation is used to:
o A) Increase the alcohol content
o B) Decrease the alcohol content
o C) Remove water
o D) Both A and C
o Correct Answer: D
21. Vacuum distillation is used when:
o A) Components have very high boiling points
o B) Components have very low boiling points
o C) Components react with oxygen
o D) Components need to be separated quickly
o Correct Answer: A
22. What is the primary advantage of steam distillation over simple distillation?
o A) It requires less energy
o B) It allows distillation at lower temperatures
o C) It is faster
o D) It produces purer products
o Correct Answer: B
23. In extractive distillation, a third component called a solvent is added to:
o A) Increase the boiling point of the mixture
o B) Decrease the boiling point of the mixture
o C) Enhance the separation of components
o D) Change the color of the mixture
o Correct Answer: C
24. Molecular distillation is a type of distillation used for:
o A) High molecular weight substances
o B) Low molecular weight substances
o C) Metals
o D) Gases
o Correct Answer: A
25. A common problem in distillation where the vapor does not fully condense is called:
o A) Flooding
o B) Foaming
o C) Weeping
o D) Partial condensation
o Correct Answer: D
26. Flooding in a distillation column can be caused by:
o A) Too high a reflux ratio
o B) Too low a reflux ratio
o C) Insufficient heating
o D) Too much cooling
o Correct Answer: A
27. Weeping in a distillation column refers to:
o A) Liquid flowing back down the column
o B) Vapor rising too quickly
o C) Liquid droplets being carried up the column
o D) Excessive condensation in the column
o Correct Answer: A
28. A key safety concern during distillation is:
o A) Fire hazard due to flammable liquids
o B) Electrical hazards
o C) Biological contamination
o D) Both A and B
o Correct Answer: D
29. Which personal protective equipment (PPE) is essential when performing distillation?
o A) Safety goggles
o B) Lab coat
o C) Gloves
o D) All of the above
o Correct Answer: D
30. Proper ventilation is important during distillation to:
o A) Prevent overheating
o B) Remove toxic vapors
o C) Maintain constant temperature
o D) Increase distillation efficiency
o Correct Answer: B
31. Who is credited with the development of the first modern distillation apparatus?
o A) Antoine Lavoisier
o B) Robert Boyle
o C) John Dalton
o D) Ibn Sina (Avicenna)
o Correct Answer: D
32. Raoult's Law relates to:
o A) Boiling points of pure substances
o B) Vapor pressure of solutions
o C) Melting points of mixtures
o D) Density of liquids
o Correct Answer: B
33. Dalton's Law is applicable in distillation for calculating:
o A) Total pressure of a mixture of gases
o B) Total volume of a liquid mixture
o C) Boiling point of a single component
o D) Condensation rate of a vapor
o Correct Answer: A
34. When distilling an ethanol-water mixture, which component will distill first?
o A) Ethanol
o B) Water
o C) Both at the same rate
o D) Neither
o Correct Answer: A
35. In a laboratory, simple distillation is typically used to:
o A) Separate azeotropic mixtures
o B) Purify solvents
o C) Create new compounds
o D) Measure boiling points
o Correct Answer: B
36. A common solvent distilled for reuse in laboratories is:
o A) Acetone
o B) Chloroform
o C) Hexane
o D) All of the above
o Correct Answer: D
37. Distilled water is often used in:
o A) Drinking
o B) Laboratory experiments
o C) Car batteries
o D) All of the above
o Correct Answer: D
38. Which household appliance uses a form of distillation?
o A) Refrigerator
o B) Air conditioner
o C) Humidifier
o D) Coffee maker
o Correct Answer: C
39. Essential oils are often extracted through:
o A) Simple distillation
o B) Fractional distillation
o C) Steam distillation
o D) Vacuum distillation
o Correct Answer: C
40. The Fenske equation is used to calculate:
o A) Minimum number of theoretical plates
o B) Reflux ratio
o C) Boiling point elevation
o D) Distillation time
o Correct Answer: A
41. The McCabe-Thiele method is a graphical technique for determining:
o A) Number of stages in a distillation column
o B) Temperature profile in distillation
o C) Vapor-liquid equilibrium
o D) Condensation rates
o Correct Answer: A
42. Relative volatility is a measure of:
o A) The ease of separation of components
o B) The density difference of components
o C) The solubility of components
o D) The viscosity of components
o Correct Answer: A
43. Which compound is typically removed from crude oil first during distillation?
o A) Gasoline
o B) Kerosene
o C) Diesel
o D) Bitumen
o Correct Answer: A
44. The term "head" in distillation refers to:
o A) The first fraction collected
o B) The last fraction collected
o C) The middle fraction collected
o D) The residue left in the flask
o Correct Answer: A
45. Which of the following does not affect the efficiency of a distillation column?
o A) Column diameter
o B) Column height
o C) Ambient temperature
o D) Packing material
o Correct Answer: C
46. During distillation, what happens when the heating rate is too high?
o A) Better separation
o B) More impurities in distillate
o C) Lower temperature
o D) No change in distillation rate
o Correct Answer: B
47. Reflux in a distillation process refers to:
o A) The condensed liquid that is returned to the column
o B) The vapor that rises up the column
o C) The liquid collected at the bottom of the column
o D) The gas emitted from the column
o Correct Answer: A
48. In industrial distillation, a sieve tray is used to:
o A) Separate solid impurities
o B) Increase contact between liquid and vapor
o C) Reduce column pressure
o D) Measure liquid flow
o Correct Answer: B
49. In an azeotropic distillation, a new component is added to:
o A) Create a new azeotrope
o B) Break the existing azeotrope
o C) Lower the boiling point of the azeotrope
o D) Increase the boiling point of the azeotrope
o Correct Answer: B
50. What is the primary difference between batch and continuous distillation?
o A) Batch distillation processes in stages
o B) Continuous distillation operates non-stop
o C) Batch distillation is less efficient
o D) Both A and B
o Correct Answer: D
51. Cryogenic distillation is used for the separation of:
o A) Hydrocarbons
o B) Air into its components
o C) Water from alcohol
o D) Organic compounds
o Correct Answer: B
52. The Murphree efficiency is a measure of:
o A) Heat transfer efficiency
o B) Mass transfer efficiency
o C) Energy consumption
o D) Vapor pressure
o Correct Answer: B
53. In a petrochemical refinery, which distillation product has the highest boiling point?
o A) Gasoline
o B) Kerosene
o C) Diesel
o D) Residual oils
o Correct Answer: D
54. Which factor is least likely to cause fouling in a distillation column?
o A) High temperature
o B) Corrosive materials
o C) High purity feed
o D) Solid contaminants
o Correct Answer: C
55. Which of the following is an advantage of packed columns over plate columns?
o A) Higher pressure drop
o B) Greater liquid hold-up
o C) Lower cost for large diameters
o D) Easier to clean
o Correct Answer: C
56. If the relative volatility of a binary mixture is 1, this indicates that:
o A) The mixture is easy to separate
o B) The mixture is an azeotrope
o C) The mixture cannot be separated by distillation
o D) The components have very different boiling points
o Correct Answer: B
57. The term "boil-up rate" refers to:
o A) The rate at which liquid is added to the column
o B) The rate at which vapor is generated in the reboiler
o C) The rate at which distillate is collected
o D) The rate of condensation in the condenser
o Correct Answer: B
58. In a binary distillation, the mole fraction of the more volatile component in the vapor phase is:
o A) Higher than in the liquid phase
o B) Lower than in the liquid phase
o C) Equal to the liquid phase
o D) Unrelated to the liquid phase
o Correct Answer: A
59. In vacuum distillation, the pressure is reduced to:
o A) Increase the boiling points
o B) Decrease the boiling points
o C) Increase the condensation rate
o D) Decrease the distillation time
o Correct Answer: B
60. In fractional distillation of crude oil, which fraction is collected at the top of the column?
o A) Heavy oils
o B) Light gases
o C) Diesel
o D) Lubricating oils
o Correct Answer: B
61. Which of the following is not a feature of molecular distillation?
o A) Operates at low pressure
o B) Uses a high vacuum
o C) Ideal for high molecular weight substances
o D) Uses high temperatures
o Correct Answer: D
62. In designing a distillation column, the height of the column is primarily determined by:
o A) The diameter of the column
o B) The number of theoretical plates required
o C) The type of condenser used
o D) The feed composition
o Correct Answer: B
63. What is the purpose of a reboiler in a distillation column?
o A) To cool the vapor
o B) To heat the bottom liquid
o C) To condense the distillate
o D) To remove impurities
o Correct Answer: B
64. The term "downcomer" in a distillation column refers to:
o A) The pathway for vapor to rise
o B) The pathway for liquid to descend
o C) The condenser connection
o D) The feed inlet
o Correct Answer: B
65. Which type of distillation column packing provides the largest surface area for vapor-liquid
contact?
o A) Random packing
o B) Structured packing
o C) Plate trays
o D) Sieve trays
o Correct Answer: B
66. According to the Gibbs phase rule, for a binary distillation with two phases in equilibrium, the
degrees of freedom are:
o A) 1
o B) 2
o C) 3
o D) 0
o Correct Answer: B
67. The Kremser equation is used to determine:
o A) The number of stages in absorption
o B) The boiling point elevation
o C) The efficiency of distillation
o D) The reflux ratio
o Correct Answer: A
68. The term "dew point" in the context of distillation refers to:
o A) The temperature at which vapor begins to condense
o B) The temperature at which liquid begins to boil
o C) The pressure at which liquid vaporizes
o D) The point where the mixture is in liquid form
o Correct Answer: A
69. The "overhead product" in a distillation column is also known as:
o A) Bottoms
o B) Distillate
o C) Feed
o D) Reflux
o Correct Answer: B
70. In a distillation column, the "bottoms" product refers to:
o A) The most volatile component
o B) The least volatile component
o C) The feed mixture
o D) The vapor phase
o Correct Answer: B
71. The temperature gradient in a distillation column typically:
o A) Decreases from bottom to top
o B) Increases from bottom to top
o C) Remains constant
o D) Is unpredictable
o Correct Answer: A
72. In the production of spirits, the "heads" fraction is typically:
o A) Retained for its high alcohol content
o B) Discarded due to impurities
o C) Recycled into the next batch
o D) Used as the main product
o Correct Answer: B
73. Distillation columns in petrochemical plants are often constructed from:
o A) Glass
o B) Stainless steel
o C) Plastic
o D) Copper
o Correct Answer: B
74. Which component in a distillation apparatus provides thermal energy to the system?
o A) Condenser
o B) Distillation flask
o C) Heating mantle
o D) Fractionating column
o Correct Answer: C
75. The primary function of a distillation column is to:
o A) Provide a large surface area for vapor-liquid equilibrium
o B) Increase the pressure of the vapor
o C) Decrease the temperature of the liquid
o D) Mix the components thoroughly
o Correct Answer: A
76. In chemical laboratories, vacuum distillation is often used to:
o A) Separate high-boiling components
o B) Separate low-boiling components
o C) Mix chemical reagents
o D) Conduct low-temperature reactions
o Correct Answer: A
77. Petroleum refineries use which type of distillation for separating crude oil?
o A) Steam distillation
o B) Fractional distillation
o C) Simple distillation
o D) Vacuum distillation
o Correct Answer: B
78. The term "boiling point elevation" refers to:
o A) The increase in boiling point of a solution compared to the pure solvent
o B) The boiling point at high altitudes
o C) The decrease in boiling point under vacuum
o D) The normal boiling point of a liquid
o Correct Answer: A
79. A reflux ratio of 2:1 in a distillation process means:
o A) Twice as much liquid is returned to the column as is collected as distillate
o B) Half as much liquid is returned to the column as is collected as distillate
o C) The same amount of liquid is returned as collected
o D) Twice as much distillate is collected as returned
o Correct Answer: A
80. In the context of essential oil extraction, which plant material is commonly used in steam
distillation?
o A) Lavender
o B) Cactus
o C) Oak
o D) Grass
o Correct Answer: A
81. Distillation columns in the chemical industry are sometimes operated at pressures higher than
atmospheric to:
o A) Increase the boiling points of the components
o B) Decrease the boiling points of the components
o C) Speed up the distillation process
o D) Reduce the risk of fire
o Correct Answer: A
82. Which distillation method is typically used for purifying heat-sensitive organic compounds?
o A) Simple distillation
o B) Fractional distillation
o C) Steam distillation
o D) Molecular distillation
o Correct Answer: D
Historical and Conceptual Understanding
83. The concept of "ideal plates" in distillation was first introduced by:
o A) Raoult
o B) Fenske
o C) McCabe and Thiele
o D) Murphree
o Correct Answer: C
84. Which of the following describes an azeotropic mixture?
o A) A mixture with a constant boiling point
o B) A mixture with varying boiling points
o C) A mixture that can be easily separated by distillation
o D) A mixture that solidifies upon cooling
o Correct Answer: A
85. During distillation, the rate of distillation can be controlled by adjusting the:
o A) Condenser temperature
o B) Heating rate
o C) Column height
o D) Distillate collection rate
o Correct Answer: B
86. In batch distillation, the composition of the distillate:
o A) Remains constant
o B) Changes over time
o C) Is always the same as the feed
o D) Is not affected by reflux ratio
o Correct Answer: B
87. In a laboratory setting, which piece of glassware is typically used to heat the mixture in
distillation?
o A) Beaker
o B) Erlenmeyer flask
o C) Round-bottom flask
o D) Test tube
o Correct Answer: C
88. To ensure smooth boiling during distillation, which material is often added to the distillation
flask?
o A) Boiling chips
o B) Stirring rods
o C) Thermometers
o D) Reflux rings
o Correct Answer: A
89. In industrial distillation, tray columns are preferred over packed columns when:
o A) Large diameters are required
o B) Low pressure drop is needed
o C) Corrosive materials are processed
o D) High efficiency is not necessary
o Correct Answer: A
90. A disadvantage of using a packed column for distillation is:
o A) Higher pressure drop
o B) Higher cost for small diameters
o C) Less efficient separation
o D) Difficulty in handling high throughputs
o Correct Answer: D
91. Raoult’s Law is applicable to:
o A) Non-ideal solutions
o B) Ideal solutions
o C) Colloidal solutions
o D) Suspensions
o Correct Answer: B
92. In an ideal binary distillation, the composition of the distillate compared to the composition of
the bottom product is:
o A) The same
o B) Richer in the more volatile component
o C) Richer in the less volatile component
o D) Unpredictable
o Correct Answer: B
93. To avoid bumping during distillation, one should:
o A) Use a very high heating rate
o B) Add anti-bumping granules
o C) Remove the condenser
o D) Increase the vacuum pressure
o Correct Answer: B
94. A properly insulated distillation column will:
o A) Lose more heat to the surroundings
o B) Increase the efficiency of separation
o C) Decrease the rate of distillation
o D) Have no effect on the process
o Correct Answer: B
95. The term "azeotropic distillation" is used when:
o A) A solvent is added to break an azeotrope
o B) An azeotrope is formed to simplify separation
o C) Azeotropes are used as solvents
o D) No separation is possible
o Correct Answer: A
96. In a distillation column, weeping refers to:
o A) Liquid flowing through the perforations in a tray
o B) Vapor passing through the downcomer
o C) Excessive reflux
o D) A high rate of distillation
o Correct Answer: A
97. During fractional distillation, the main difference between the top and bottom of the column is:
o A) Pressure
o B) Temperature
o C) Density of the liquid
o D) Viscosity of the liquid
o Correct Answer: B
98. Vacuum distillation is often preferred for:
o A) Separating compounds with very high boiling points
o B) Increasing the efficiency of separation
o C) Reducing the cost of distillation
o D) Simplifying the distillation process
o Correct Answer: A
99. To improve the efficiency of a distillation column, one might:
o A) Increase the reflux ratio
o B) Decrease the number of trays
o C) Lower the column height
o D) Reduce the feed rate
o Correct Answer: A
100. In steam distillation, the purpose of steam is to:
A. Heat the mixture above its boiling point
B. Lower the boiling points of the components
C. Act as a solvent for non-volatile components
D. Condense
the vapor
Correct Answer: B
