Questions on Sublimation
20 Multiple-Choice Questions on Sublimation
1. What is sublimation?
A) Change from liquid to gas
B) Change from solid to liquid
C) Change from gas to solid
D) Change from solid to gas
E) Change from gas to liquid
2. Which of the following substances commonly undergoes sublimation at room temperature?
A) Water
B) Dry ice (solid CO₂)
C) Iron
D) Ethanol
E) Mercury
3. Sublimation is a type of:
A) Chemical reaction
B) Endothermic physical change
C) Exothermic chemical change
D) Redox process
E) Precipitation reaction
4. In sublimation, the substance skips which phase?
A) Gas
B) Solid
C) Liquid
D) Plasma
E) Vapor
5. Which of the following best represents sublimation?
A) Melting butter
B) Boiling water
C) Frost forming
D) Dry ice disappearing
E) Dew forming
6. What is required for sublimation to occur?
A) Low temperature and high pressure
B) High humidity
C) High temperature and low pressure
D) Presence of light
E) Electricity
7. Which of these is an industrial application of sublimation?
A) Electrolysis
B) Filtration
C) Chromatography
D) Freeze-drying (lyophilization)
E) Fermentation
8. What kind of energy is absorbed during sublimation?
A) Electrical energy
B) Kinetic energy
C) Thermal (heat) energy
D) Sound energy
E) Mechanical energy
9. Which phase change is the reverse of sublimation?
A) Melting
B) Vaporization
C) Condensation
D) Deposition
E) Freezing
10. What type of intermolecular forces must be overcome for sublimation to happen?
A) Only ionic
B) Van der Waals only
C) Intermolecular (all types)
D) Covalent bonds
E) Hydrogen bonding only
11. Sublimation occurs more readily when:
A) Atmospheric pressure is increased
B) The solid is very dense
C) The surface area of the solid is minimized
D) Pressure is low and temperature is high
E) Light is shined on the solid
12. What happens to the temperature of a substance during sublimation?
A) Increases rapidly
B) Remains constant during the phase change
C) Decreases significantly
D) Doubles instantly
E) Drops to absolute zero
13. Which of the following materials can be purified by sublimation?
A) Table salt
B) Sand
C) Naphthalene
D) Plastic
E) Iron filings
14. Sublimation can be used to:
A) Determine molecular mass
B) Measure viscosity
C) Purify volatile solids
D) Break chemical bonds
E) Create solutions
15. Which of the following does not typically sublimate?
A) Iodine
B) Naphthalene
C) Camphor
D) Water
E) Silver
16. Why does dry ice sublimate instead of melt at room pressure?
A) Its melting point is too high
B) It reacts with air
C) It decomposes before melting
D) Atmospheric pressure is below its triple point
E) It is magnetic
17. Sublimation is commonly used in which of the following?
A) Brewing
B) Dry cleaning
C) Printing (dye-sublimation)
D) Electroplating
E) Baking
18. What property of substances makes them good candidates for sublimation?
A) High boiling point
B) Weak intermolecular forces and high vapor pressure
C) High density
D) Metallic bonding
E) Large molecular size
19. In the sublimation of iodine, what is typically observed?
A) White vapor
B) Blue liquid
C) Violet vapor
D) Red solid
E) Orange smoke
20. Sublimation is used in freeze-drying because it:
A) Converts solid water directly into vapor, removing moisture
B) Freezes bacteria
C) Destroys microorganisms
D) Increases food temperature
E) Adds water to food
Answers with Explanations
1. D – Sublimation is the transition from solid directly to gas.
2. B – Dry ice (solid CO₂) sublimates at room temperature.
3. B – It absorbs heat; therefore, it's an endothermic physical change.
4. C – Sublimation skips the liquid phase.
5. D – Dry ice turns directly into carbon dioxide gas.
6. C – High temperature and low pressure favor sublimation.
7. D – Freeze-drying uses sublimation to remove water.
8. C – Heat energy is required to overcome attractions between particles.
9. D – Deposition is the gas-to-solid transition.
10. C – Sublimation requires overcoming all types of intermolecular forces present.
11. D – Low pressure and high temperature allow direct transition to gas.
12. B – The temperature remains constant during the phase change.
13. C – Naphthalene can be purified by sublimation.
14. C – Sublimation is used to purify volatile solids.
15. E – Silver is metallic and does not sublimate under normal conditions.
16. D – CO₂ sublimates at room pressure because it’s below its triple point.
17. C – Dye-sublimation printing is widely used in textiles and graphics.
18. B – Volatile solids with high vapor pressure and weak forces sublimate easily.
19. C – Sublimed iodine forms violet vapors.
20. A – Freeze-drying removes ice by sublimating it directly into vapor.
Share Online!
