Carbonic acid

Carbonic acid is a very unstable, weak acid formed in small concentrations with dissolution of its anhydride, carbon dioxide, in water. Any solution containing it also contains molecular carbon dioxide dissolved in water.

Properties

Physical

Anhydrous carbonic acid cannot be isolated under normal conditions. Only in extreme conditions it becomes stable and isolable. Solutions of carbonic acid typically resemble soda water or mineral water (and usually are soda water or mineral water).

Chemical

Carbonic acid is a weak diprotic acid. Its first dissociation gives H+ and the hydrocarbonate anion, HCO₃^-. The second dissociation gives another H+ and the carbonate anion, CO₃^2-.

Solutions of carbonic acid and carbon dioxide react with alkaline bases, forming carbonate salts.

Sources and production

Solutions of carbon dioxide containing carbonic acid are sold as carbonated water.

Such a solution can also be made by reacting any carbonate salt with any acid stronger than carbonic acid. It can also be made from water and carbon dioxide using a soda siphon or carbonator.

Projects

• Make calcium bicarbonate

Handling

Safety

Solutions of carbonic acid are absolutely safe. They can be consumed by humans with no ill effects, providing no other chemicals are present in the solution. They are well known for the peculiar taste and refreshing effect provided by bubbles of carbon dioxide.

Storage

Solutions of carbonic acid can be stored in closed plastic bottles. You know, the same way you store soda. Because they are soda.

Disposal

Carbonic acid does not require any special disposal and can be poured down the drain.