Question

Give examples of sublimation.

Answer 1

The conversion of a substance from solid to gaseous state directly without it becoming a liquid is called sublimation. It is an endothermic process. In other words, sublimation is the change or transition from the solid phase into the gas phase without entering the liquid phase.

Complete step-by-step answer: Generally, solid passes through the liquid phase and then into the gas phase. However, there are certain situations where a solid enters the gas phase directly without going through the liquid phase. Such a process is called sublimation.
It is the change or transition from the solid phase into the gas phase without entering the liquid phase.
The opposite process of this where the gas goes directly to the solid phase is called deposition.
The solid that undergoes the change to form is called sublime. The solid obtained by cooling of the vapors is called sublimate.
Few examples of sublimation are-
1.Naphthalene balls used in mothballs readily sublime at room temperature and pressure.
2.Dry ice which is solid carbon dioxide readily sublimes at room temperature and pressure.
The efficiency of the sublimation process depends on the vapor pressure of the solid that is to be purified and also of the impurities that are to be removed.

Note: It is very important to note that the term sublimation is application only when a purely physical change of state happens. A chemical reaction resulting in the formation of gas from solid is not sublimation.