| IUPAC name
| Other names
|Molar mass||84.45914 g/mol|
|Appearance||Colorless unstable liquid|
|Density||1 g/mL, solution (approximate)|
|>40 g/100 ml (20 °C)|
|Solubility||Soluble in methanol|
|Safety data sheet||Sigma-Aldrich (35% aq. sol.)|
| Hydrochloric acid|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Chloric acid is an unstable, strong, oxidizing acid that can exist in aqueous solutions up to 40%. It is one of the oxoacids of chlorine. Its formula is HClO3.
Chloric acid solutions are colorless liquids. Their density is similar to that of water. Concentrated chloric acid (over 30%) has a pungent smell, because of its disproportionation and release of chlorine and chlorine dioxide.
Chloric acid is stable in cold aqueous solution up to a concentration of approximately 30%, and solution of up to 40% can be prepared by careful evaporation under reduced pressure. Above these concentrations, chloric acid solutions decompose to give a variety of products, for example:
- 8 HClO3 → 4 HClO4 + 2 H2O + 2 Cl2 + 3 O2
- 3 HClO3 → HClO4 + H2O + 2 ClO2
Chloric acid is a strong oxidizer. Concentrated solutions can light organic materials on fire. It is also a strong acid. It reacts with bases to form chlorate salts.
When one tries to prepare an overconcentrated solution of this acid (over 40% under vacuum, over 30% by normal pressure boiling), it disproportionates to give a variety of products, which always include perchloric acid, and gases such as chlorine and chlorine dioxide are released. Because of this, chloric acid can serve as a precursor chemical to perchloric acid.
The easiest way to prepare this acid is reacting barium chlorate with sulfuric acid. Concentrations should be stoichiometrically calculated to avoid accidentally preparing an overconcentrated solution that will decompose instantly.
- Make perchloric acid
- Make various exotic chlorates for your fireworks, i.e. strontium chlorate for red, calcium chlorate for orange, etc.)
Chloric acid is corrosive, similarly to nitric acid of the same concentrations. It is also known to react violently with oxidizable organic materials. The products of its decomposition are toxic gases.
Solutions up to 30% can be stored in bottles of amber glass, with ample headroom for gases evolving when the acid decomposes. 31-40% solutions are not advised to store.