1. What happens in sublimation?
a) Solid vaporizes in liquid phase
b) A liquid vaporizes in gas phase
c) A gas solidifies
d) A solid vaporizes in gas phase without going in liquid phase
Explanation: In sublimation, a solid vaporizes in gas phase without going in liquid phase.
2. What happens in desublimation?
a) Solid vaporizes in liquid phase
b) A liquid vaporizes in gas phase
c) A gas solidifies without changing to liquid
d) A solid vaporizes in gas phase without going in liquid phase
Explanation: In desublimation, a gas solidifies in solid phase without going in liquid phase.
3. What are sublimation and desublimation governed by?
a) Liquid vapor pressure
b) Solid vapor pressure
c) Amount of solid present
d) Partial pressure of gas
Explanation: At low pressures both sublimation and desublimation are governed by solid vapor pressure.
4. What happens at equilibrium during sublimation?
a) Vapor pressure of liquid is equal to solid
b) Vapor pressure of solid is equal to vapor pressure of gas
c) Vapor pressure of solid is equal to partial pressure of solute in gas
d) Vapor pressure of solid is equal to partial pressure of solute in liquid
Explanation: During sublimation, the solid vapor pressure is equal to partial pressure of solute in gas.
5. When does the sublimation take place?
a) The partial pressure of solute in gas phase is more than solid vapor pressure
b) The partial pressure of solute I gas phase is more than solid vapor pressure
c) The vapor pressure is equal to partial pressure
d) When sufficient heat is applied
Explanation: Sublimation will only be taking place when the partial pressure is lesser in gas because the difference is the driving force.
6. What is the remainder product of sublimation called?
a) Subliment
b) Solute
c) Solvent
d) Sublimate
Explanation: The solid remaining is termed as sublimate.
7. Which of the following is not an example of sublimate?
a) Camphor
b) Naphthalene
c) Iodine.
d) Nitrates
Explanation: Iodine is not a sublimate since it gets sublimated and not left behind.
8. Which of the following solids undergo sublimation?
a) Sodium chloride
b) Iodine crystals
c) Sodium carbonate
d) Sodium bicarbonate
Explanation: Iodine has high melting point and sublimes easily.
9. A mixture of ammonium chloride and sodium chloride is separated by using:
a) Distillation
b) Crystallization
c) Sublimation
d) Magnetic separation
Explanation: Ammonium chloride is sublimable, hence sublimation is used.
10. How is propylene-propane mixture separated?
a) Distillation
b) Crystallization
c) Adsorption
d) Sublimation
Explanation: Adsorption technique is used using adsorbent silica gel for separating propylene-propane mixture.