carbonic acid

American  

noun

1. the acid, H 2 CO 3 , formed when carbon dioxide dissolves in water, known in the form of its salts and esters, the carbonates.

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carbonic acid British  

noun

1. a weak acid formed when carbon dioxide combines with water: obtained only in aqueous solutions, never in the pure state. Formula: H 2 CO 3

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carbonic acid Scientific  

/ kär-bŏn′ĭk /

1. A weak, unstable acid present in solutions of carbon dioxide in water. It gives carbonated beverages their sharp taste. Chemical formula: H ₂ CO ₃ .

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Etymology

Origin of carbonic acid

First recorded in 1785–95

Example Sentences

That weak carbonic acid ultimately soaks into the soil, full of carbon dioxide.

From Slate • Oct. 17, 2025

This happens because carbon dioxide from the air dissolves in rainwater to form carbonic acid - this then percolates through the rock and reacts with it, causing it to dissolve.

From BBC • Feb. 19, 2025

The carbon dioxide, buffered into carbonic acid, increases acidity in ocean water, which is bad news for corals, clams and other shell-forming creatures.

From Los Angeles Times • Jun. 5, 2024

When the plant parts are exposed to oxygen and other substances, the organic carbon begins to decompose into inorganic carbon, which can be dissolved into carbonic acid in the water.

From Science Daily • May 31, 2024

Other organisms form carbon dioxide, which, as carbonic acid, aids in dissolving rock.

From "Silent Spring" by Rachel Carson