What is the Difference Between Effervescence and Efflorescence

The key difference between effervescence and efflorescence is that effervescence is the escape of gases from a solution, whereas efflorescence is the migration of a salt to the surface of a porous material where it tends to form a coating.

Although the terms effervescence and efflorescence sound similar, they are not the same. These terms have very different definitions.

CONTENTS

1. Overview and Key Difference
2. What is Effervescence
3. What is Efflorescence
4. Effervescence vs Efflorescence  in Tabular Form
5. Summary – Effervescence vs Efflorescence

What is Effervescence?

Effervescence is the escape of gases from an aqueous solution, causing the formation of foam or fizzing. This term originates from the Latin word “fervere” meaning, “to boil”. We can observe this process during the opening of a bottle of champagne, beer,  and other carbonated drinks. These visible bubbles form when dissolved gas escapes the solution. This dissolved gas is not visible in its dissolved state. Moreover, a smaller bubble size can make a smoother beer head. Carbon dioxide is a common gas dissolved in carbonated drinks, but we can observe the presence of nitrogen gas in some beers.

We can observe effervescence in a laboratory when adding hydrochloric acid to a block or limestone. We can witness the effervescence of carbon dioxide when a few pieces of marble or an antacid tablet is put into hydrochloric acid in a test tube fitted with a bung.

What is Efflorescence?

Efflorescence is the migration of a salt to the surface of a porous material where it tends to form a coating. This process involves the solution of a salt that is held internally in water or some other solvent. Here, the water having the salt tend to migrate to the surface where it gets evaporated, leaving the salt as a coating.

There are two types of efflorescence as primary efflorescence and secondary efflorescence. In primary efflorescence, the water acts as the invader where it already contains the salt internally. Secondary efflorescence is a reverse process where the salt originally occurs externally, and it is taken into the solution before migrating to the surface.

We can observe efflorescence occur in natural or in-built environments. When considering the porous materials in construction, this process can cause an outer cosmetic problem. Sometimes, it can also cause some internal structural weaknesses. In addition, this process can cause the clogging of pores of the porous material, which results in the destruction of the material upon an internal water pressure, e.g. spalling or brick.

What is the Difference Between Effervescence and Efflorescence?

Although the terms effervescence and efflorescence sound similar, they are not the same. These terms have very different definitions. The key difference between effervescence and efflorescence is that effervescence is the escape of gases from a solution, whereas efflorescence is the migration of water that contains a salt towards a surface where water gets evaporated, leaving a salt coating on the surface. For example, bubbling effects in beer, and carbonated drinks are examples of effervescence whereas salt coatings on construction material and porous material which clogs the pores are examples of efflorescence.

The following table summarizes the difference between effervescence and efflorescence.

Summary – Effervescence vs Efflorescence

The key difference between effervescence and efflorescence is that effervescence is the escape of gases from an aqueous solution causing the formation of foam or fizzing whereas efflorescence is the migration of a salt to the surface of a porous material where it tends to form a coating.

Reference:

1. “What Is Efflorescence?: How to Prevent It and Remove It.” Nitterhouse Masonry, 13 Apr. 2021.

Image Courtesy:

1. “Soda bubbles macro” By en:User:Spiff – From en:Image:Soda bubbles macro.jpg (Public Domain) via Commons Wikimedia
2. “Robert moses secondary efflorescence 2” By Achim Hering – Own work (CC BY 3.0) via Commons Wikimedia