Chloric acid

Chloric acid
Names


Other names Chloric(V) acid
Identifiers
CAS Number	7790-93-4
3D model (JSmol)	Interactive image
ChemSpider	18513
ECHA InfoCard	100.029.303
EC Number	232-233-0
PubChem CID	19654
UNII	Z0V9L75H3K
UN number	2626
CompTox Dashboard (EPA)	DTXSID1047449
InChI InChI=1/ClHO3/c2-1(3)4/h(H,2,3,4) Key: XTEGARKTQYYJKE-UHFFFAOYAG
SMILES O[Cl+2]([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 (pK_a)	−2.7^[1]
Conjugate base	Chlorate
Structure
Molecular shape	pyramidal
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Oxidant, Corrosive
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H271, H314
Precautionary statements	P210, P220, P221, P260, P264, P280, P283, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P306+P360, P310, P321, P363, P370+P378, P371+P380+P375, P405, P501
NFPA 704 (fire diamond)	3 0 2 OX
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
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

Chloric acid, H Cl O₃, is an oxoacid of chlorine, and the formal precursor of chlorate salts. It is a strong acid (pK_a ≈ −2.7) and an 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:

8 HClO₃ → 4 HClO₄ + 2 H₂O + 2 Cl₂ + 3 O₂

3 HClO₃ → 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 → 2 HClO₃ + BaSO₄

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

3 HClO → HClO₃ + 2 HCl

References

^ Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (2007). Lehrbuch der anorganischen Chemie (in German). Berlin. ISBN 978-3-11-017770-1. OCLC 180963521.{{cite book}}: CS1 maint: location missing publisher (link)

Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
R. Bruce King, ed. (1994). "Chloric acid". Encyclopedia of Inorganic Chemistry. Vol. 2. Chichester: Wiley. p. 658. ISBN 0-471-93620-0.