Difference between boiling and evaporation

Difference between boiling and evaporation

Vaporization is a phase transition process in which a substance changes its state from liquid to vapor. It can occur in two ways: evaporation and boiling. The evaporation process involves the phase transition at a temperature below the boiling temperature. On the other hand, the boiling of a substance occurs at the boiling point, which can vary with the variation of the environmental pressure.

The water boils at 100 C and the temperature does not rise even if heat is continuously supplied to it. On the contrary, the evaporation rate depends on the surface area, meaning that the larger the area, the faster the process would be. Let's take a look at the article provided below that simplifies the difference between boiling and evaporation.

Comparative chart

Basis for comparison Boiling Evaporation
Sense Boiling involves a vaporization process that transforms the liquid into gas when it is heated continuously. Evaporation is a natural process, in which the liquid changes its shape to gas due to the increase in temperature or pressure.
Phenomenon Mass Surface
Required temperature It occurs only at the boiling point. It occurs at any temperature
bubbles Form bubbles It does not form bubbles.
Power The source of energy required. The energy supplied by the surrounding environment.
Liquid temperature Remains constant decreases

Definition of boiling

Boiling is a physical change and a type of rapid vaporization in which the liquid is converted into steam when it is constantly heated to a temperature such that the vapor pressure of the liquid equals the external pressure exerted by the surrounding environment.

The temperature at which boiling begins is known as the boiling point. It depends on the pressure exerted on the liquid, that is, the higher the pressure, the higher the boiling point. In the boiling process, when the molecules of the substance are so widespread that it can change its state, the bubbles form and boiling begins.

In this process, as we heat the liquid, the pressure of the vapor rises, until it is equal to the atmospheric pressure. After that, the formation of bubbles will take place inside the liquid and will pass to the surface and burst with the consequent release of gas. Even if we add more heat to the liquid, the boiling temperature will be the same.

Definition of Evaporation

The process in which an element or compound is converted from the liquid state to the gaseous state, due to the increase in temperature and / or pressure known as evaporation. The process can be used to separate the solid dissolved in the liquid, such as salt dissolved in water. a surface phenomenon, that is, from the surface of the liquid to the vapor.

Thermal energy is the fundamental requirement for evaporation, that is to divide the bonds that hold water molecules together. In this way, it helps the water to evaporate slowly, to the freezing point.

Evaporation largely depends on the temperature and quantity of water present in the water body, i.e. the higher the temperature and the more water present, the higher the evaporation rate. The process can take place in both natural and artificial environments.

Key differences between boiling and evaporation

The following points are noteworthy as they explain the difference between boiling and evaporation:

  1. Boiling refers to the vaporization process, in which the liquid state is transformed into the gaseous state, at a defined boiling point. On the contrary, evaporation defined as a natural process, in which the increase in temperature and / or pressure changes liquid into gas.
  2. Boiling is a bulk phenomenon in the sense that it occurs throughout the liquid. On the contrary, evaporation of surface phenomena, which occur only on the liquid surface.
  3. The boiling of a liquid occurs only at the boiling point of that liquid, that is, it occurs only at a defined temperature. On the other hand, the evaporation process can take place at any temperature.
  4. In boiling, bubbles form inside the liquid, then move upwards and burst into gas, while no bubbles are formed in the evaporation process.
  5. While the source of energy required in the boiling process, the evaporation energy supplied by the surrounding environment.
  6. In boiling, the temperature of the liquid remains the same, while in case of evaporation the temperature of the liquid tends to decrease.


To summarize, boiling a process faster than evaporation, as the liquid molecules move faster in boiling than in the evaporation process. While boiling produces heat and does not cause the liquid to cool, evaporation leads to the cooling of the liquid.