3 P2O3 + 2 HBrO3 + 9 H2O → 2 HBr + 6 H3PO4

This is an oxidation-reduction (redox) reaction:

6 PIII - 12 e- → 6 PV (oxidation)

2 BrV + 12 e- → 2 Br-I (reduction)

P2O3 is a reducing agent, HBrO3 is an oxidizing agent.

Reactants:

  • P2O3
    • Names: Phosphorus trioxide source: wikipedia, accessed: 2019-09-27, Phosphorus(III) oxide source: wikipedia, accessed: 2019-09-27, Phosphorus sesquioxide source: wikipedia, accessed: 2019-09-27
    • Appearance: Colourless monoclinic crystals or liquid source: wikipedia, accessed: 2019-09-27
  • HBrO3 – Bromic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Bromic(V) acid source: wikipedia, accessed: 2019-09-27
  • 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

Products:

  • HBr – Hydrogen bromide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Bromane source: wikipedia, accessed: 2019-09-27source: wikipedia, accessed: 2019-09-27
    • Other names: Hydrobromic acid source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04, Hydronium bromide source: wikipedia, accessed: 2019-09-27, HBr source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless gas source: wikipedia, accessed: 2019-09-27; Colorless/faint yellow liquid source: wikipedia, accessed: 2019-09-27; Colourless compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Colorless gas with a sharp, irritating odor. [Note: Shipped as a liquefied compressed gas. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02
  • H3PO4
    • Names: Phosphoric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Orthophosphoric acid source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Phosphoric(V) acid source: wikidata, accessed: 2019-09-02
    • Appearance: Hygroscopic colourless crystals source: ICSC, accessed: 2019-09-04; Thick, colorless, odorless, crystalline solid. [Note: Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02