Evaporation vs. Boiling
What is the difference between evaporation and boiling?
Many people assume that evaporation and boiling refer to the same process, but they are actually two different processes even though they may have the same result. Both release water into the air as water vapor but in evaporation this only occurs in the water that is on the surface. Since boiling water means that all of the water has reached the boiling temperature, the whole mass of the water is affected.
There is also a difference in the time it takes for evaporation and boiling to occur. Evaporation is a slow and gradual process, but boiling takes place very quickly. In evaporation the vaporization of water from the surface can take a long time. When water is boiled it doesn’t take very long for it to reach the point where it evaporates into the air and the boiling point of water is only reduced when the conditions that brought it to a boil are reduced.
Different factors can affect the rate at which water evaporates. These include:
- The concentration of other substances in the air
- The concentration of the substance that is evaporating
- The rate at which the air is flowing
- The inter-molecular forces acting on both the liquid and the air
- Surface area
- Temperature, and
There are three different kinds of boiling:
- Nucleate boiling
- Transition boiling
- Film boiling
There are no advantages attributed to the evaporation of water, but there are advantages to boiling water. These include making it safe to drink and making it nutritious to use for cooking. There is also a disadvantage to boiling in that foods that are boiled lose some of their nutrients in the evaporation process.
Boiling causes bubbles to form, but this does not happen in evaporation. Evaporation can also occur at any temperature but the temperature has to be really high for water to boil. This is called the boiling point. Particles also move very rapidly in boiling than they do in evaporation.