Chloric Acid - Wikipedia

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 (pKa)	−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 2OX
Related compounds
Other anions	bromic acidiodic acid
Other cations	ammonium chloratesodium chloratepotassium chlorate
Related compounds	hydrochloric acidhypochlorous acidchlorous acidperchloric 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, HClO3, is an oxoacid of chlorine, and the formal precursor of chlorate salts. It is a strong acid (pKa ≈ −2.7) and an oxidizing agent.

Properties

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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.[2] Above these concentrations, chloric acid solutions decompose to give a variety of products, for example:[2]

8 HClO3 → 4 HClO4 + 2 H2O + 2 Cl2 + 3 O2 3 HClO3 → HClO4 + H2O + 2 ClO2

When it reacts, it forms chlorate (ClO3) salts.

Hazards

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Chloric acid is a powerful oxidizing agent which ignites most organic materials on contact. It is also corrosive.[3]

Production

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Chloric acid may be produced from barium chlorate through its reaction with sulfuric acid, resulting in a solution of chloric acid and insoluble barium sulfate precipitate:[4]

Ba(ClO3)2 + H2SO4 → 2 HClO3 + BaSO4

The chlorate must be dissolved in boiling water and the acid should be somewhat diluted in water and heated before mixing.

Another method which can be used to produce solutions up to 10% concentration is by the use of cation exchange resins and a soluble salt such as NaClO3, where the Na+ cation will exchange with H+.[4]

Another method is the heating of hypochlorous acid, producing chloric acid and hydrogen chloride:[citation needed]

3 HClO → HClO3 + 2 HCl

Any way it is produced, the acid may be concentrated up to 40% in a vacuum dessicator over H2SO4.[4]

See also

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• Chlorate
• Hypochlorous acid
• Chlorous acid
• Perchloric acid
• Oxidizing acid
• Dichlorine pentoxide

References

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1. ^ 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)
2. ^ a b Kirk-Othmer, ed. (2001-01-26). Kirk-Othmer Encyclopedia of Chemical Technology (1 ed.). Wiley. doi:10.1002/0471238961.0308121513051404.a01.pub2. ISBN 978-0-471-48494-3.
3. ^ "Chloric acid". PubChem. National Institute of Health.
4. ^ a b c Brauer, Georg; Schmeisser, M. (1963). "5. Chlorine, Bromine, Iodine". In Riley, Reed F. (ed.). Handbook of Preparative Inorganic Chemistry (2nd ed.). New York, London: Academic Press. pp. 312–313. ISBN 9780121266011. Retrieved 6 December 2024. {{cite book}}: ISBN / Date incompatibility (help)

Additional Information

[edit]

• Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. doi:10.1016/C2009-0-30414-6. 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.

v t e Hydrogen compounds

H3AsO3 H3AsO4 HArF HAt HSO3F H[BF4] HBr HBrO HBrO2 HBrO3 HBrO4 HCl HClO HClO2 HClO3 HClO4 HCN HCNO H2CrO4/H2Cr2O7 H2CO3 H2CS3 HF HFO HI HIO HIO2 HIO3 HIO4 HMnO4 H2MnO4 H2MoO4 HNC NaHCO3 HNCO HNO HNO2 HNO3 H2N2O2 HNO5S H3NSO3 H2O H2O2 H2O3 H2O4 H2O5 H3PO2 H3PO3 H3PO4 H4P2O7 H5P3O10 H[AuCl4] H2[PtCl6] H2OsCl6 H2S H2S2 H2Se H2SeO3 H2SeO4 H4SiO4 H2[SiF6] HSCN HNCS H2SO3 H2SO4 H2SO5 H2S2O3 H3O H2S2O6 H2S2O7 H2S2O8 CF3SO3H H2Te H2TeO3 H6TeO6 H4TiO4 H2Po H[Co(CO)4]

v t e Salts and covalent derivatives of the chlorate ion

HClO3 He LiClO3 Be B C NH4ClO3 O F Ne NaClO3 Mg(ClO3)2 Al(ClO3)3 Si P S Cl Ar KClO3 Ca(ClO3)2 Sc Ti V Cr Mn(ClO3)2 Fe(ClO3)3 Co(ClO3)2 Ni(ClO3)2 Cu(ClO3)2 Zn(ClO3)2 Ga(ClO3)3 Ge As Se Br Kr RbClO3 Sr(ClO3)2 Y(ClO3)3 Zr Nb Mo Tc Ru Rh Pd AgClO3 Cd(ClO3)2 In Sn Sb Te I Xe CsClO3 Ba(ClO3)2 * Lu Hf Ta W Re Os Ir Pt AuClO3 Hg(ClO3)2 Tl Pb(ClO3)2 Bi Po At Rn Fr Ra(ClO3)2 ** Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og   * La(ClO3)2 Ce Pr(ClO3)2 Nd Pm Sm Eu Gd Tb Dy Ho Er(ClO3)2 Tm Yb ** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No