Sublimation

Sublimation is an interesting phenomenon, wherein the gas is derived from a solid without passing through the liquid phase. Sublimation is shown by camphor in real life as it directly goes from the solid to the gaseous state, without passing through the liquid state.

In this article, we will learn about, Sublimation Definition, the Process of Sublimation, the Application of sublimation, and others in detail.

Sublimation Example

What is Sublimation?

Sublimation is the process of changing a solid into a gas directly. It is similar to when the ice cubes evaporate without even melting into the water. Under specific circumstances, some elements go directly from the solid to the gaseous state. Sublimation is a phenomenon whereby there is a transformation between solids and gases without an interim of liquids.

This takes place as the substance undergoes alterations in temperature and pressure which bypass the liquid stage and directly convert the material from solids to gases.

Meaning of Sublimation

Sublimation means the change of phase of an solid object to vapour phase directly, without coming to the liquid phase. This is most commonly seen in camphour(kapoor). When we burn some camphour it directly changes to vapour phase without actually common to liquid phase.

Sublimation Diagram

This is shown in the image added below shows sublimation diagram.

Definition of Sublimation

• Sublimation is the phase transition process by which a substance changes directly from solid state to gaseous state without ever passing through an intermediate liquid stage.
• In sublimation, the solid particles will absorb energy (usually heat), gain sufficient kinetic energy to break all of the intermolecular forces that keep them in a fixed and organized structure. So instead of becoming a liquid, the solid turns into a gas.

Applications of Sublimation

The process of sublimation is used in various fields of science and industries,

• Sublimation is something forensic science needs. Forensic evidence can be brought out from paper by sublimation using iodine.
• The chemist can further refine volatile compounds through sublimation. This is very helpful for organic materials.
• Inkjet printers are now being replaced by dye-sublimation. Because the prints dry as soon as they come out of the printer, printouts are ready to use immediately.
• Synthetic materials like polyester are printed using a dye sublimation method used in the textile industry. With this technique, T-shirts as well as flags and banners can all be made.
• Items printed by dye sublimation are varied, and include pens as well as coffee cups or bags. The cost is low.
• Iodine sublimation can also bring out latent fingerprints on paper.
• This technology is used by space agencies such as NASA and ISRO to provide its human charges in orbit with wholesome food. It is applied when the food product involved must be stored for a long time.
• In the frozen foods industry, sublimation is used in freeze-drying. As the surrounding area pressure decreases, water trapped within in solid form is released into gas phase.

Examples of Sublimation

Some examples where sublimation is used are,

• Dry Ice (Solid Carbon Dioxide): The example of sublimation widely spread in nowadays is dry ice. It undergoes sublimation at atmospheric pressure into a gaseous state and produces a fog-like effect.
• Iodine Crystals: Iodine in solid form sublimates without the need for heat at room temperature. Iodine crystals do not turn to liquid when they become exposed to the air, but rather convert directly into purple vapors.
• Naphthalene: Another substance which sublimates is naphthalene commonly found in moth balls. Naphthalene molecules have a tendency of turning into gas over time and gradually mothballs get smaller.
• Camphor: This solid form of camphor that is common in some medical products or moth repellents volatilizes at room temperature producing its odor molecules.
• Snow and Frost: Water vapor in the air may also condense directly into ice (frost), which is termed as deposition, especially in colder climates. The other side of this is known as desublimation.
• Ammonium Chloride: Solid ammonium chloride is a common laboratory substance and it sublimes on heating, giving off white vapors. This feature enables its use for many chemical procedures.
• Anthracene: The compound anthracene is a crystalline material for making dyes and plastics that sublimes at points higher than their melting point.

Sublimation in Daily Life Use

Various uses of sublimation in daily life are,

• Dry ice: It sublimates in a closed container at room temperature. In specialized effects for fog, this is used most times especially during keeping cool of things.
• Air Fresheners: Air fresheners that rely on sublimation as a way of releasing a smell. This is what happens when one opens up the package and the solid air fresher slowly becomes a gas thereby releasing the smell.
• Mothballs: Substances such as naphthalene and paradichlorobenzane in mothballs sublimate a little to produce repelling fumes against these pies.
• Freeze-Dried Food: They include some sublimable freeze-dried foods such as instant coffee and dried fruits. Ice undergoes direct transformation into steam without removing water through a heating process.
• Snow and Frost: The process whereby water vapors that skip the liquid phase and directly form crystals of ice on surfaces is known as deposition that gives frost on a cold morning.
• Printing: In particular, sublimation is common in printing technology, particularly in the dye-sublimation printing practice. The solid ink is turned into a gas that doesn’t liquefy but instead bonds directly to materials like paper and cloth.

Condensation, Evaporation and Sublimation

The difference between Condensation, Evaporation and Sublimation is added in the table below,

Property	Condensation	Evaporation	Sublimation
Definition	In this process gases cools down and liquid is formed	In this process gases absorbs heat and change into vapour state	In this process a substance is directly changed from solid to gaseous stste.
Occurs	Gas cools down	Liquid heats up	Exposed to reduced pressure
Energy	Releases heat	Absorbs heat	Releases or Absorbs depending on the direction) of the change
Phase change	Gas to Liquid	Liquid to Gas	Solid to Gas
Environmental Impact	Cloud formation, Precipitation	Drying of surfaces, Cooling Effect	Use in freeze-drying air fresheners.
Examples	Water droplets forming on a cold surface.	Drying of wet clothes.	Dry ice (solid carbon dioxide) turning to gas.

Read More,

• Filtration
• Pure and Impure Substances
• Separation of Mixtures using Sublimation and Magnets

Sublimation – Solved Examples

Example 1: The researchers place 10 grams of iodine (I₂) into a sealed chamber and heat it. If all the iodine sublimes, calculate the final volume of iodine vapor at STP (Standard Temperature and Pressure: 0°C and 1 atm). Also, determine the amount of moles of iodine by using its molecular weight.

Solution:

Moles of I₂ = Mass ⁄ Molar mass = 10g ⁄ 253.80g/mol ≈ 0.0394 mol

One mole of any gas takes 22.4 liters at standard temperature and pressure (STP)

Volume of 0.0394 Moles of Iodine vapor at STP = Moles of I₂ × Molar volume under STP

Volume = 0.0394 mol × 22.4 L = 0.0087 m = 883 ml

Hence, approximately 0.883 litres of the initial volume of iodine vapor is left over in standard temperature and pressure conditions after the sublimation of 10 gm of pure iodine.

Example 2: In an open container at room temperature (25 °C at 1 atm) 0.05 gram of solid iodine (I2) sublime each minute. Given that there are 10 grams of solid iodine at the start of this exercise, what is the quantity will be after 2 hours?

Solution:

• Sublimation Rate = 0.05 gm/minute
• 10 gram initial mass of solid iodine
• Time = 2 hours

Let’s first calculate the total amount of iodine that will have sublimed after 2 hours

Time = 120 minutes = 2 hrs

Rate of sublimation per minute equal to 0.05 gram

Total Sublimation for 120 minutes = Time of Sublimation Per Minute × Total Time

Total Sublimation = (0.05 gram/min × 120 min) = 6 grams

Now, subtract the total sublimated amount from the initial amount to find the remaining iodine

Remaining Iodine = Initial mass – Total sublimation

Remaining Iodine = 10 grams – 6 grams = 4 grams

Thus, 2 hours later the vessel there will be 4 gram of iodine left.

Example 3: Sublimation of a sample of 10 gram of camphor. About 70 % of camphor goes into solution on sublimation. Determine the mass of camphor that sublimes and the mass of the residues formed.

Solution:

• Mass of Camphor = 10 g
• Camphor which undergoes sublimation = 70%

Let’s calculate the mass of camphor that undergoes sublimation

Mass of camphor vaporized is approximately seventy percent ten grams

7 gms mass of camphor sublime.

Now, to find the mass of the residue left behind

Residue Mass = Mass of Camphor – Mass of Sublimed Camphor

Residual Mass = 3 gm

Therefore,

• Sublimated Masses of Camphor = 7 gm
• Residue Mass Left After Burn-Off = 3 gm

Example 4: A sample of (I2) weighs 10 grams. It undergoes complete sublimation when heated and the content of the container (after the process) is discovered to weigh 8 grams. Determine how much iodine has evaporated.

Solution:

Total mass shed during sublimation which is mass of iodine that has sublimated

10 gm of Initial Iodine

Container’s Final Mass = 8 grams

Mass of Sublimated Iodine = Initial Mass Iodine – Final Mass of Container

Iodine masses sublimed = 10 grams − 8 grams

Iodine masses sublimed = 2 grams

Accordingly, it can be affirmed that 2 grams of the compound have been sublimated in the process.

Sublimation – Practice Questions

Q1. What are Conditions that Govern Sublimation of a Solid at a Certain Temperature and Pressure?

Q2. Sublimation Causes Cooling Effects Why?

Q3. Describe Effects of Surface Area and Particle Size on Rate of Sublimation.

Q4. Differentiate between Deposition and Sublimation, Providing Examples of Each Process.

Q5. What are Some Substances that Demonstrate Sublimation?

Sublimation-FAQs

1. What is Sublimation with Example?

Sublimation is the process of change for a solid into a gas directly. Examples: camphor, iodine, ammonium chloride, naphthalene, etc.

2. How is Sublimation used in Daily Life?

Various example on sublimation observed in daily life are,

• Food preservation
• Dye-Sublimation Printing
• Household Products
• Laboratory Applications, etc.

3. When Sublimation Occurs?

Sublimation occurs under specific conditions related to temperature and pressure.

4. What makes Sublimation Unique?

Sublimation is different from the other processes such as melting and boiling since it changes directly from solid to gas without passing through a liquid state.

5. Why is Sublimation different from Evaporation?

The phenomenon of sublimation is whereby matters go through change from solid state into gas form without conversion into liquid.

6. Is Sublimation Reversible Process?

Yes, sublimation is a reversible adjustment of temperature and atmospheric pressure leads gas derived from the sublimation process to decompose into solid state.