Question

Iodine, camphor, ammonium chloride and naphthalene. Name the characteristics that are common to all these materials.
A. equal densities
B. sublimation property
C. equal melting point
D. pure homogeneous mixtures.

Answer 1

Hint: Sublimation is a process by which a kind of phase transition, or a variation in a state of matter, such as freezing, melting, and evaporation. Through this process, a substance varies its state from solid to a gas without ever passing through a liquid phase. Solid CO2, dry ice are the common examples of sublimation.

Complete answer:
Sublimation is defined as the process in which a substance varies directly to the gaseous phase from the solid state. That means the substance will not pass through the liquid phase when the phase is changed from solid to gas. Naphthalene, iodine and camphor all get vaporised directly from their solid phase itself. When the solid iodine crystals are heated by keeping it in a beaker with hot sand in it, the iodine, the process of sublimation occurs. As the iodine gas gets in contact with the cold glass it differs in phase to a solid state, but never into a liquid form. In the case of ammonium chloride, after the heating process it will sublime, and it will be directly converted into vapour and this vapour will again condense at the upper colder part of the funnel to create solid ammonium chloride. Hence we can conclude that the sublimation property is common for all the given substances.

So, the correct answer is “Option B”.

Note:
Sublimation is an endothermic reaction that happens at temperatures and pressures below the triple point of a substance. This corresponds to the least value of pressure at which the substance can exist as a liquid. Sublimation is a spontaneous process in the case of solid carbon dioxide.