Chloric acid

Chloric acid

Names
Other names Chloric(V) acid
Identifiers
CAS Number	7790-93-4
ChemSpider	18513
Jmol 3D model	Interactive image
InChI InChI=1/ClHO3/c2-1(3)4/h(H,2,3,4) Key: XTEGARKTQYYJKE-UHFFFAOYAG
SMILES O=Cl(=O)O
Properties
Chemical formula	HClO3
Molar mass	84.45914 g mol−1
Appearance	colourless solution
Density	1 g/mL, solution (approximate)
Solubility in water	>40 g/100 ml (20 °C)
Acidity (pKa)	ca. −1
Structure
Molecular shape	pyramidal
Vapor pressure	{{{value}}}
Related compounds
Other anions	bromic acid iodic acid
Other cations	ammonium chlorate sodium chlorate potassium chlorate
Related compounds	hydrochloric acid hypochlorous acid chlorous acid perchloric acid
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Infobox references

Chloric acid, HClO₃, is an oxoacid of chlorine, and the formal precursor of chlorate salts. It is a strong acid (pK_a ≈ −1) and oxidizing agent.

Properties

Chloric acid is thermodynamically unstable with respect to disproportionation.

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:

8HClO₃ → 4HClO₄ + 2H₂O + 2Cl₂ + 3 O₂

3HClO₃ → HClO₄ + H₂O + 2 ClO₂

Hazards

Chloric acid is a powerful oxidizing agent. Most organics and flammables will deflagrate on contact.

Production

It can be prepared by the reaction of sulfuric acid with barium chlorate, the insoluble barium sulfate being removed by precipitation:

Ba(ClO₃)₂ + H₂SO₄ → 2HClO₃ + BaSO₄

Another method is the heating of hypochlorous acid, producing chloric acid and hydrogen chloride:

3HClO → HClO₃ + 2 HCl

See also

• Chlorate
• Hypochlorous acid
• Chlorous acid
• Perchloric acid
• Oxidizing acid