2 HClO3 + H2SO3 → 2 ClO2 + H2SO4 + H2O

This is an oxidation-reduction (redox) reaction:

SIV - 2 e- → SVI (oxidation)

2 ClV + 2 e- → 2 ClIV (reduction)

H2SO3 is a reducing agent, HClO3 is an oxidizing agent.

Reactants:

  • HClO3
    • Names: Chloric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Chloric(V) acid source: wikipedia, accessed: 2019-09-27, HClO3 source: wikidata, accessed: 2019-09-02
    • Appearance: Colourless solution source: wikipedia, accessed: 2019-09-27
  • H2SO3 – Sulfurous acid source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02
    • Other names: S(O)(OH)2 source: wikidata, accessed: 2019-09-02, Sulphurous acid source: wikidata, accessed: 2019-09-02

Products:

  • ClO2 – Chlorine dioxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, 4-chlorane (substitutive) OR Dioxidochlorine(•) (additive) --> source: wikipedia, accessed: 2019-09-27
    • Other names: Chlorine(IV) oxide source: wikipedia, accessed: 2019-09-27, Chlorine oxide source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Chlorine peroxide source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: Yellow to reddish gas source: wikipedia, accessed: 2019-09-27; Red-yellow gas with pungent odour source: ICSC, accessed: 2019-09-04; Yellow to red gas or a red-brown liquid (below 52°F) with an unpleasant odor similar to chlorine and nitric acid. source: NIOSH NPG, accessed: 2019-09-02
  • H2SO4 – Sulfuric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Oil of vitriol source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sulfuric acid, concentrated (> 51% and < 100%) source: ICSC, accessed: 2019-09-04, H2SO4 source: wikidata, accessed: 2019-09-07
    • Appearance: Clear, colorless liquid source: wikipedia, accessed: 2019-09-27; Odourless colourless oily hygroscopic liquid source: ICSC, accessed: 2019-09-04; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02
  • H2O – Water, oxidane source: wikipedia, accessed: 2019-09-27
    • Other names: Water (H2O) source: wikipedia, accessed: 2019-09-27, Hydrogen hydroxide (HH or HOH) source: wikipedia, accessed: 2019-09-27, Hydrogen oxide source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas source: wikipedia, accessed: 2019-09-27