Introduction to Sublimation Meaning
Substances undergo a change of phase when they experience certain conditions. Sublimation meaning refers to a substance’s transition directly from the solid phase to the gas phase without passing through the intermediate liquid phase. Sublimation is an endothermic process that occurs at temperatures and pressures below the triple point of a chemical in the phase diagram.
Experts call the triple point as the temperature and pressure of a substance, at which its solid, liquid and gaseous phase coexist in complete equilibrium. In the reverse process of sublimation, some chemicals pass directly from the gas phase to the solid phase, without passing through the intermediate liquid phase. We shall here discuss here sublimation meaning and process in detail.
Source: en.wikipedia.org
Sublimation Meaning: Process
Sublimation refers to a physical change of state of matter. When some of the molecules absorb heat energy, they acquire much higher energy than what their neighbours acquire. Consequently, they overcome the forces of attraction and escape into the vapour phase.
Since this requires additional energy, we called it as an endothermic reaction. Enthalpy of sublimation is the heat or energy that is necessary to change the state from solid to gas. Its unit is KJ/mol or even KJ/kg.
A few examples of sublimation:
- Naphthalene balls readily sublimate at room temperature and pressure.
- Dry ice that is solid carbon dioxide readily sublimates at room temperature and pressure.
Applications of Sublimation
Air freshener- One of the applications of sublimation is air freshener in which a solid’s direct conversion takes place into a gas form which keeps our bathroom fresh. When we heat the air fresheners while taking hot water bath, we can see the transition from solid to the gas phase.
We should take some adequate precautions when heating such substances. Another application is Naphthalene balls. Camphor is another substance that sublimes to give a very pleasant smell. In the printing press, there are specialized printers that work on the sublimation process.
In the process of printing, the ink turns from solid to gas and then again into the solid phase. These techniques used in fabric printing are also used in the textile industry.
Freeze-drying- Experts call the sublimation process in the frozen food industry as freeze-drying. The frozen water in the material will sublimate from the solid phase to the gas phase when you reduce the surrounding pressure.
There is no heat involved in the removal of the water. Sublimation results in a high-quality product because it makes use of extremely low temperatures. The shape of the product remains in the original form and once we rehydrate the product, it has excellent quality.
This technique is used when the foodstuffs are to be preserved for a longer period. NASA scientists use this method to preserve food for a longer time for astronauts.
Printers- Dye-sublimation printers are now replacing inkjet printers. In the textile industry, dye sublimation process is used to printing in synthetic fabrics like polyester.
The advantage in the textile industry is that the printing colours are extremely brilliant. This is due to the bonding of the dye to the synthetic fibres. Products like coffee mugs, pens, and bags printing use dye sublimation at very low cost.
Solved Question For You
Q: Which solid that undergoes sublimation?
A. argon
B. iodine
C. sodium chloride
D. water
Ans: The correct option is B. When sublimation of iodine takes place, it forms a visible purple gas. When solid iodine crystals are heated, the iodine will change directly from a solid to a gas without passing through a liquid phase.
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