Sublimation is process of conversion of solid directly into gas.
In general scenario, Ice coverts to water and this water converts to water vapor (gas).
So the process of conversion of states of matter is solid converts to liquid and this liquid boils out to give gas.
Solid →liquid→Gas (normal transition of matter).
Solid→ Gas (Sublimation phenomenon)
So the process is devoid of liquid state during transition.
What is sublimation process:
In general matter has particles bound together by inter molecular and intra-molecular forces. These forces help keep the matter bulky, hard and stable. When we provide heat energy to this matter, the forces of attraction are overcome due to vibrations of atoms in the molecules leading loss if stability and hardness. The molecules
tend to arrange themselves in loose fashion such that they start flowing like a liquid without any shape.
On providing further energy, these molecules begin to vibrate with greater intensity than before and tend to move apart from each other. They exist as gas which have loosely bound molecules. These molecules are free to move and try to occupy the open space as much as possible.
But volatile substances tend to directly convert from solid to gas at room temperature. This phenomenon of conversion directly from solids to gases is called as sublimation.
Examples of sublimation include:
1. Naphthalene: When used as insecticide and put between clothes, we can notice that it loses weight gradually. This loss of weight is due to sublimation. Napthalene ball converts slowly to gas on standing.
2. Water: Even water show this behavior at triple point.
3. Iodine: Iodine is a good example for sublimation.
Uses sublimation helps to dry substance within getting moist. This process of sublimation is also beneficial in medicine. It is used in making powders from heat sensitive materials etc.