HIO3 + 3 H2SO3 → 3 H2SO4 + HI

This is an oxidation-reduction (redox) reaction:

3 SIV - 6 e- → 3 SVI (oxidation)

IV + 6 e- → I-I (reduction)

H2SO3 is a reducing agent, HIO3 is an oxidizing agent.

Reactants:

  • HIO3
    • Names: Iodic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Iodic(V) acid source: wikipedia, accessed: 2019-09-27, [IO2(OH)] source: wikidata, accessed: 2019-09-02
    • Appearance: White solid 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:

  • 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
  • HI – Iodane source: wikipedia, accessed: 2019-09-27
    • Other names: Hydroiodic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Hydrogen iodide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Hydronium iodide source: wikipedia, accessed: 2019-09-27
    • Appearance: Colorless liquid source: wikipedia, accessed: 2019-09-27; Colorless gas source: wikipedia, accessed: 2019-09-27; Colourless compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04