Difference Between Boiling and Condensation

Main Difference – Boiling vs Condensation

Boiling and condensation are two chemical terms used to express phase changes of matter. Boiling refers to the change of phase from liquid to gas. This change occurs at a specific temperature called boiling point. The boiling point of a pure substance is a unique property for that substance, but if impurities are present, the boiling point may alter. Condensation refers to the change of phase from gas to liquid. It is the opposite of boiling. This phase change is used in some chemical techniques such as reflux. The main difference between boiling and condensation is that boiling is the change of a liquid into its vapor phase whereas condensation is the change of vapor into its liquid phase.

Key Terms: Boiling, Condensation, Gas, Liquid, Phase of Matter, Vapor, Vaporization

Key Areas Covered

1. What is Boiling
      – Definition, Characteristics, Phase Change
2. What is Condensation
      – Definition, Characteristics, Phase Change
3. What is the Difference Between Boiling and Condensation
      – Comparisons of Key Differences

Key Terms: Boiling, Boiling Point, Condensation, Liquid, Phase Change, Vapor

Difference Between Boiling and Condensation - Comparison Summary

What is Boiling

Boiling is the vaporization of a liquid at a particular temperature. A phase change occurs here from liquid phase to gaseous phase. The boiling point is the temperature at which a liquid boils. In other words, it is the temperature at which the vapor pressure of a liquid is equal to the external pressure that is applied to the liquid by the surrounding environment.

Difference Between Boiling and Condensation

Figure 1: Boiling of Water

The boiling point of a liquid varies with the atmospheric pressure. Hence, the value of the boiling point for a certain liquid is not always constant. The atmospheric pressure varies according to the elevation. For example, water normally boils at 1000C when the atmospheric pressure is 1 atm. But at higher altitudes, water boils at lower temperatures. This is because the vapor pressure should be equal to the atmospheric pressure for a liquid to boil. As the pressure at higher altitudes is lower, a low heat energy (temperature) is enough to meet the above criteria.

Even at temperatures below the boiling point, liquid molecules will become vapor due to a process called evaporation. Evaporation is the escaping of liquid molecules that are located on the surface of a liquid. These molecules are only loosely bound to the other molecules in the liquid; thus, they can easily detach from other molecules and escape the liquid as vapor. But in boiling, molecules located anywhere in the liquid are able to escape the liquid.

What is Condensation

Condensation is the conversion of a substance (such as water) from the vapor state to a denser liquid or solid state, usually initiated by a reduction in temperature of the vapor.  Hence, it is the change of phase of matter from gas to liquid phase. It is the opposite of boiling.

Condensation starts with the formation of atomic or molecular clusters. If not, condensation starts when a gaseous phase of a substance comes into contact with a liquid or a solid surface.

Main Difference - Boiling vs Condensation

Figure 2: Condensation on Water Bottle

Condensation can be observed in nature, in the water cycle. Therefore, it is a naturally occurring incident. In the water cycle, the water vapor in air converted into liquid water. This condensation is responsible for the formation of clouds.

Difference Between Boiling and Condensation

Definition

Boiling: Boiling is the vaporization of a liquid at a particular temperature.

Condensation: Condensation is the conversion of a substance (such as water) from the vapor state to a denser liquid or solid state usually initiated by a reduction in temperature of the vapor.  

Change of Phase

Boiling: Boiling involves the change of phase from liquid to vapor phase.

Condensation: Condensation involves the change of phase from vapor to liquid phase.

End Products

Boiling: Boiling forms vapor.

Condensation: Condensation forms liquid droplets.

Conclusion

Boiling and condensation are two opposite chemical processes that involve the change of phase of matter. The main difference between boiling and condensation is that boiling is the change of a liquid in to its vapor phase whereas condensation is the change of vapor into its liquid phase.

Reference:

1. “Boiling.” Wikipedia, Wikimedia Foundation, 11 Jan. 2018, Available here.
2. “Condensation – The Water Cycle.” Condensation – The Water Cycle, from USGS Water-Science School, Available here.

Image Courtesy:

1. “Boiling Water” by Scott Akerman (CC BY 2.0) via Flickr
2. “Condensation on water bottle” (CC BY-SA 3.0) via Commons Wikimedia

About the Author: Madhusha

Madhusha is a BSc (Hons) graduate in the field of Biological Sciences and is currently pursuing for her Masters in Industrial and Environmental Chemistry. Her interest areas for writing and research include Biochemistry and Environmental Chemistry.

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