Question

Explain sublimation with an example.

Answer 1

Sublimation can be defined as the transition of a substance from solid to gaseous phase without forming the liquid phase. It is an endothermic phase transition that takes place at a temperature and pressure below the triple point of the substance.

Complete step by step answer:
Elements and compounds mainly have three different states at different temperatures. The transition from solid state to gaseous state will need a transition of solid-state to liquid state and then to liquid state to a gaseous state. If the vapour pressure solids are sufficient at temperature then they can directly sublime into the air, the gaseous phase. Sublimation is shown by solids that have high pressure at their triple point. The point at which pressure and temperature of the substance are such that it can exist in all the three states of matter simultaneously, this is called triple point, it is a characteristic point of a substance.
Some day to day examples of sublimation are,
A. Sublimation of dry ice, dry ice is a frozen form of carbon dioxide. When this gets exposed to air, dry ice directly changes its phase from solid-state to gaseous state that can be seen as fog. Frozen carbon dioxide is more stable in a gaseous state than in its solid-state.
B. Sublimation is naphthalene is another well-known example, it is an organic compound. Naphthalene is used as pesticides in mothballs. Naphthalene sublimes due to the presence of non-polar molecules that are held together by Van Der Waals force of attraction. It also desublimates at low temperature to form needle-like crystals.
The transformation from solid state to gaseous state without forming liquid state is sublimation. Example is sublimation of camphor.

Note: The process of sublimation happens more easily when the air is dry and when the ice is close to the melting point of water.
sublimation is shown by a wide range of solids, including water, iodine, arsenic, and solid carbon dioxide (dry ice). They can sublimate at normal temperatures and pressures. Some materials can also be made to sublimate by creating conditions of low pressure.