Sublimation vs Evaporation: Difference and Comparison

Mother Earth has undergone many physical and chemical changes since it was created. These continuous changes on the planet have led to the existence of life on Earth.

From taking oxygen to breathe to the exhalation of it, plants preparing food to animals relying on them, everything has small or complex reactions associated with it. And while these reactions occur, the state of the matter changes from one another.

Key Takeaways

1. Sublimation is changing a solid directly into a gas without going through the liquid state. In contrast, Evaporation is changing a liquid into a gas by heating or boiling it.
2. Sublimation occurs when the pressure of the surrounding atmosphere is lower than the vapor pressure of the solid. In contrast, Evaporation occurs when the vapor pressure of the liquid is higher than the surrounding atmospheric pressure.
3. Sublimation is used in freeze-drying, where water is removed from a substance while it is frozen. In contrast, Evaporation is used in distillation, where a mixture of liquids is separated based on their boiling points.

Sublimation vs Evaporation

The difference between Sublimation and Evaporation is that Sublimation can be defined as a process of changing the solid state of any matter directly into the gaseous state of that matter (there is no existence of liquid phase or state in this process) and vice versa while comparatively, on the other hand, Evaporation can be defined as the process in which the liquid state of any matter changes into its gaseous state or phase.

Sublimation is a transition process in which a solid state of matter is directly changed into the gaseous state of matter and vice-versa. It is an endothermic phase transition process that occurs at low pressure and temperature than that of the triple point of the same substance.

This process is used to describe the physical changes which cause changing of solid-state to gas or vice versa and not the chemical changes which cause a chemical to change from solid-state to gaseous state or gaseous state to solid-state.

Evaporation is a process of a liquid phase or state that changes into a gaseous state or phase. It occurs below the temperature at which the element or compound boils.

Evaporation plays an important role in maintaining the humidity in the air and also helps in maintaining the exchange of energy system of the earth, which produces the atmospheric motion and the weather and climate of the earth.

Comparison Table

Parameters of Comparison	Sublimation	Evaporation
Definition	It is a process when the solid-state changes directly into a gaseous state or vice versa.	It is a process in which the liquid state changes into the gaseous state.
Initial Phase	Solid Phase	Liquid Phase
Enthalpy	It gives the amount of energy required for sublimation.	It gives the enthalpy required for evaporation.
Phase Change	Solid to Gas (no liquid phase)	Liquid to Gas
Occurrence	Below the triple point of the substance	On the surface of the liquid
Example	Naphthalene	Water (in liquid form) to water vapor

What is Sublimation?

Sublimation can be defined as the change of the state of a solid into the state of a gas without changing in the liquid state and vice versa. Sublimation indicates physical changes that change the substance’s phase from solid to gas or gas to solid.

Many chemical changes are wrongly understood under the process of sublimation. Some chemical reactions undergo a direct phase change. Sublimation processes occur at a low temperature and pressure below that of the triple point of the given substance.

It is an endothermic reaction as it releases energy when the substance’s state or phase changes. The amount of energy required for the sublimation process is known as the enthalpy of sublimation or heat of sublimation.

There are many applications of the sublimation process used in many industries. The sublimation process is used in dry-sublimation printers, which replaced the inkjet printers in the market. These printers are very efficient because the prints get easily dried up. It is used in purifying volatile compounds.

Examples of a sublimation process are Naphthalene is, an organic compound which sublimes at a temperature of 176F. The dry ice (the ice) is one of the great examples of the process which directly changes from a solid state to a gaseous state.

What is Evaporation?

The process of Evaporation can be defined as the process of change of the state of liquid into the state of the gas. The evaporation process occurs below the level at which the substance boils.

Or in simple words, evaporation, in general, is known as the process of liquid water to water vapour in the atmosphere. It is the major source of replenishing the humidity in the air from the sea and vegetation. 

Evaporation is part of an exchange of energy in the atmosphere, which helps in maintaining the weather and climate. The difference between evaporating surface, air, relative humidity, and wind are the factors on which the evaporation of a substance depends. 

Evaporation has many applications used in varied industries and some of which are listed below:

• Indian porous clay pots called Matki/Matka use the process of evaporation to cool water.
• Clothes get dry up when hanging up on the laundry line, even when the temperature is low. This is done because the clothes dryer blows warm air and dries the clothes.
• The process is used to dry or concentrate the samples in spectroscopy, chromatography, etc. 
• It helps in the printing and coating process, and salts can be recovered from the solution, etc.

Main Differences Between Sublimation and Evaporation

1. Sublimation is the process in which the solid state of matter changes directly into the gaseous state of matter and vice versa (there is no existence of a liquid state), while on the other hand, Evaporation is the process in which the liquid state of matter changes into the gaseous state of matter. 
2. In the Sublimation process, the initial phase of the matter is the solid phase, while on the other hand, in the Evaporation process, the initial phase of the matter is the liquid phase. 
3. In the process of Sublimation, it gives the amount of energy required for the sublimation, while on the other hand, during the process of evaporation, it gives the enthalpy which is required for the evaporation.
4. In the sublimation process, the phase changes from solid to gas (no liquid phase), while on the other hand, in the evaporation process, the phase changes from liquid to gas.
5. Sublimation processes occur at low pressure and temperature below the triple point of the substance, while on the other hand, evaporation occurs on the surface of the liquid.
6. An example of the Sublimation process is naphthalene, while an example of the Evaporation process is changing of water (liquid phase) into water vapour. 

References

1. https://aip.scitation.org/doi/abs/10.1063/1.1740468?journalCode=jcp
2. https://pubs.acs.org/doi/pdf/10.1021/j100863a017
3. https://www.sciencedirect.com/science/article/abs/pii/001793109190109R
4. https://aip.scitation.org/doi/abs/10.1063/1.1740469?journalCode=jcp