Effervescence

Bubbles of carbon dioxide float to the surface of a carbonated soft drink.

Effervescence is the escape of gas from an aqueous solution and the bubbling, foaming, or fizzing that results from that release.^[1]

The word effervescence is derived from the Latin verb fervere (to boil), preceded by the adverb ex. It has the same linguistic root as the word fermentation.

Effervescence can be observed in the bubbles or foam produced by the combination of hydrochloric acid and calcium carbonate (e.g. limestone, marble, antacid tablets, etc.) as well as in the escaping bubbles of freshly opened carbonated beverages (such as soft drinks, beer, and champagne). The visible bubbles released at decompression are usually dissolved gaseous carbon dioxide escaping from a pressurized dilute solution of carbonic acid in water. The gas is not visible while dissolved in the liquid.

Examples:

CaCO₃ + 2 HCl → CaCl₂ + H₂O + CO₂

H₂CO₃ → H₂O + CO₂

Fun Facts:

Although CO₂ is most common for beverages, nitrogen gas is sometimes deliberately added to certain draught beers. The smaller bubble size creates a smoother beer head. Kegs or widgets are used due to the poor solubility of nitrogen in beer.^[2]

The tingling sensation on the back of your throat while enjoying a carbonated beverage is actually caused by the carbonic acid and not the bubbles themselves.

Effervescent tablet manufacturer Alka-Seltzer popularized the chemical reaction with their hit advertising jingle "Plop, plop, fizz, fizz, oh what a relief it is!"

^[3]

See also

Look up effervescence in Wiktionary, the free dictionary.

• Carbonation
• Effervescent tablet

References