Effervescence

{{Further information|Carbonated water}}

Although CO₂ is most common for beverages, nitrogen gas is sometimes deliberately added to certain beers. The smaller bubble size creates a smoother beer head. Due to the poor solubility of nitrogen in beer, kegs or widgets are used for this.{{cite book |last1=Baxter |first1=E. Denise |last2=Hughes |first2=Paul S. |title=Beer: Quality, Safety and Nutritional Aspects |date=2001 |publisher=Royal Society of Chemistry |isbn=9780854045884 |page=[https://archive.org/details/beerqualitysafet0000baxt/page/22 22] |url=https://archive.org/details/beerqualitysafet0000baxt |url-access=registration |quote=nitrogen gas beer}}

{{Main article|Gas evolution reaction}}

In the laboratory, a common example of effervescence is seen if hydrochloric acid is added to a block of limestone. If a few pieces of marble or an antacid tablet are put in hydrochloric acid in a test tube fitted with a bung, effervescence of carbon dioxide can be witnessed.

:{{chem2 | CaCO3 + 2 HCl -> CaCl2 + H2O + CO2↑ }}

This process is generally represented by the following reaction, where a pressurized dilute solution of carbonic acid in water releases gaseous carbon dioxide at decompression:

:{{chem2 | H2CO3 -> H2O + CO2↑ }}

In simple terms, it is the result of the chemical reaction occurring in the liquid which produces a gaseous product.G. Liger-Belair et al., "Study of Effervescence in a Glass of Champagne: Frequencies of Bubble Formation, Growth Rates, and Velocities of Rising Bubbles", [http://www.ajevonline.org Am. J. Enol. Vitic.] 50:3 (1999), 317–323.

{{Wiktionary|effervescence}}

• Cavitation
• Carbonation
• Effervescent tablet
• Precipitation (chemistry), the "down-arrow"

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{{DEFAULTSORT:Effervescence (Chemistry)}}

Category:Chemical processes