Carbon dioxide reacts with water to produce carbonic acid. The double arrow means that carbonic acid breaks down pretty readily to form carbon dioxide and water again. A hydrogen atom from the ...

Carbon dioxide dissolves in (and reacts with) water, forming carbonic acid. As this acid forms, it breaks down (dissociates) into a hydrogen ion and a bicarbonate ion. The hydrogen ion (produced when ...

Carbonic acid causes the acidity in fizzy drinks. This is used as a test for carbon dioxide. When carbon dioxide is bubbled through limewater the limewater changes from colourless to milky.