Vaporization - Definition, Factors, Process, Latent Heat, FAQs

Edited By Team Careers360 | Updated on Jul 19, 2022 08:22 PM IST

After reading this article, the reader should be able to understand the following: vaporization definition, vaporization process, vaporize meaning, the heat of vaporization definition, and latent heat of vaporization.

Define vaporization:

Vaporization is the interconversion of a liquid state into a gaseous state. Out of the three states of matter, liquid and gaseous are the two states that can be easily studied using intensive properties such as temperature, pressure, and extensive properties such as volume. These factors can affect the process of vaporization at a normal temperature and pressure; the liquid has its vapor pressure over the surface area of the liquid. All the states of matter owe their nature to the arrangement of particles at the molecular level. Therefore, these states of matter can be easily converted into each other by changing the temperature, volume, and pressure.

JEE Main 2025: Chemistry Formula | Study Materials | High Scoring Topics | Preparation Guide

JEE Main 2025: Syllabus | Sample Papers | Mock Tests | PYQs | Study Plan 100 Days

NEET 2025: Syllabus | High Scoring Topics | PYQs

Also read -

Factors affecting rate of vaporization-

There are factors such as temperature, humidity, surface area, and wind speed that can affect the rate of vaporization or evaporation-

As the temperature increases, the kinetic energy of the molecules present at the surface evaporates faster than before.
The wind speed tends to increase the rate of vaporization.
An environment full of humidity will lower down the rate of evaporation as the water vapor held by the atmosphere will be already higher.
Greater the surface area, the higher the rate of vaporization or evaporation.

JEE Main Highest Scoring Chapters & Topics

Just Study 40% Syllabus and Score upto 100%

Download EBook

Process of vaporization:

The vaporization process revolves around the change of kinetic energy into potential energy and vice versa. Suppose a liquid is subjected to heat. As the liquid starts getting heated, the kinetic energy of the molecules increases. From the postulates of the kinetic theory of the gases, we know the temperature will also increase with kinetic energy. When the liquid reaches a certain temperature there cannot be a further increase in kinetic energy. Now instead of potential energy, the heat energy supplied increases the potential energy.

With the increase in potential energy, intermolecular forces decrease, and intermolecular distance increases. The increase in the intermolecular distance leads to the interconversion of the liquid state into a gaseous state. This process is known as Boiling and the temperature at which the interconversion between two states takes place at normal atmospheric temperature is called boiling temperature.

Related Topics,

Latent heat of Vaporization-

To convert liquid into a gaseous state, the application of heat is one way to achieve the above change. However, have you ever noticed that heat supplied does not lead to an increase in temperature before the interconversion has taken place? It is only after the interconversion has completed, the temperature of the state increases.

To be precise, we can say that the change in states is dependent on absorption or liberation of heat; however, there is no association of state interconversion with the temperature change. It can be rightly said that heat energy is hidden during the interconversion of states. This hidden heat which is only used for the phase transition is called latent heat and for liquid, to gaseous transformation, it is called the latent heat of vaporization.

Also, students can refer,

Vaporization examples:

Heat supplied to boil the water leads to the formation of steam. Unless the whole water has boiled off, water continues to boil at a constant boiling temperature. The heat supplied is stored in steam and is called heat of vaporization. The latent heat of vaporization for water is 540 cal/g/⁰C.

The heat of vaporization-

The heat of vaporization is the Enthalpy change for one mole of a liquid its certain boiling point. To define enthalpy of vaporization is the same as that of the heat of vaporization.

For phase transition-

H₂O(l) H₂O(g)

Steam is formed when water boils. Its heat of vaporization is +40.79 kJ mol^-1

Any phase transformation or chemical reaction is always accompanied by absorption or release of heat energy. Enthalpy change occurring with a particular phase transition is studied as the heat of that transition. Phase transition for a system that is interconverting from a liquid to a gaseous state is studied as the heat of vaporization.

Also check-

NCERT Chemistry Notes:

Frequently Asked Questions (FAQs)

1. What are some of the factors which can affect latent heat of vaporization?

We know that vaporization is a process that has to do with the boiling point of a liquid. So, when we say factors affecting the heat of vaporization, we mean factors affecting boiling point.

Here are the factors which have a say in affecting the boiling point of the liquid-

Pressure-

If pressure is increased that means boiling temperature will increase. It is very easy to understand since if we want to change the liquid state into a vapor state there should be a change at the molecular level i.e., there should be an increase in the intermolecular distance between the molecules. But with an increase in the external pressure, it is difficult to free the molecules out of the bonds. Therefore, an increase in boiling point is required to inter-convert liquid to a gaseous state.

Addition of impurities-

Take for example a solution of water and salt. This solution will take a higher temperature (i.e., more than 100⁰C) to change its state into a gaseous form. If you add impurities to a liquid solution its boiling point tends to increase. This is because liquid takes a lesser amount of heat energy to break free from its bonds as compared to when solid substances get mixed on the surface with liquid. Solvent when mixed with non-volatile solute surrounds the solute particles, ties them down, and prevents the escape of vapor. In higher classes, we study the colligative properties, these are the properties that increase or decrease with the addition of solute particles for example- elevation in boiling point, depression in freezing point, etc.

2. Although evaporation and vaporization are two terms which are used interchangeably, how would you differentiate the two?

-First, we need to understand that evaporation and vaporization are two different phenomena. You must have seen that liquid can change into a vapor state without any supply of heat energy. When such an event occurs, we say evaporation took place. This is because evaporation can take place at temperatures below the boiling point.

-No doubt, the achieved state is gaseous in both the phenomena but vaporization is achieved at a specific boiling point of a liquid and evaporation takes place over a range of temperature and is, therefore, a relatively slower process.

-Evaporation is a surface phenomenon which means the molecules which are available at the surface can break free into vapors because of the higher kinetic energy at the surface.

3. Describe the role of kinetic energy and potential energy in the process of vaporization.

Initially, Kinetic energy increases with an increase in heat energy. Temperature also increases with an increase in kinetic energy. However, at a certain temperature, kinetic energy cannot increase any further. This kinetic energy changes into potential energy. Potential energy increases and leads to an increase in intermolecular distance and that is how interconversion takes place from a state which is liquid into a state which is gaseous.

4. What is meant by the enthalpy of vaporization?

Enthalpy of vaporization is the same as that of the heat of vaporization. It is defined as phase transformation for one mole of liquid into a gaseous state at normal pressure.

5. Mention some of the vaporization examples.

The Phenomenon of vaporization is applied into many uses.

For example- Salt is extracted from sea water by vaporization.

Clothes dry up when kept under the sun.