2 P + 6 H2O + 3 Br2 → 2 H3PO3 + 6 HBr

This is an oxidation-reduction (redox) reaction:

2 P0 - 6 e- → 2 PIII (oxidation)

6 Br0 + 6 e- → 6 Br-I (reduction)

P is a reducing agent, Br2 is an oxidizing agent.

Reactants:

  • P
    • 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
    • Br2
      • Names: Bromine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Molecular bromine source: NIOSH NPG, accessed: 2019-09-02
      • Appearance: Fuming red-to-brown liquid with pungent odour source: ICSC, accessed: 2019-09-04; Dark reddish-brown, fuming liquid with suffocating, irritating fumes. source: NIOSH NPG, accessed: 2019-09-02

    Products:

    • H3PO3 – Phosphonic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-04
      • Other names: Phosphorous acid source: wikipedia, accessed: 2019-09-27, Dihydroxyphosphine oxide source: wikipedia, accessed: 2019-09-27
      • Appearance: White solid | deliquescent source: wikipedia, accessed: 2019-09-27
    • 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