H2CO3 is commonly known as Carbonic acid. As the name suggests, this compound is an acid. Generally an acid, is a proton donor, has a pH below 7, neutralizes base and turns blue litmus paper to red. This also means that in a solution (in water) H2CO3 produces Hydronium ions (H3O+ ions).
The chemical equation for the dissociation of Carbonic acid (H2CO3) in the solution can be written as:
H2CO3 (aq) + H2O <---> H3O+ + CO3-
**hydronium ions can be represented as H3O+ or simply H+.
Carbonic acid is classified as a weak acid