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.

What does effervescent look like?

It has a white or greyish tint and consists of salt deposits left behind when water evaporates. In addition, efflorescence can appear as a powdery substance on floors and walls and requires special care to treat.

Why is effervescence observed?

Effervescence, i.e., the presence of bubbles in a liquid, can be produced both by a chemical reaction and physical phenomena. ... When dissolved in water, the chemical reaction occurs. It results in the tablet producing, as a byproduct, a gas known as carbon dioxide with the symbol, CO2.