H2SeO3 + 2 Zn + 4 HCl → 2 ZnCl2 + Se + 3 H2O

This is an oxidation-reduction (redox) reaction:

SeIV + 4 e- → Se0 (reduction)

2 Zn0 - 4 e- → 2 ZnII (oxidation)

H2SeO3 is an oxidizing agent, Zn is a reducing agent.

Reactants:

  • H2SeO3 – Selenous acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Selenic(IV) acid source: wikipedia, accessed: 2019-09-27
    • Other names: Selenious acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, [SeO(OH)2] source: wikidata, accessed: 2019-09-02, Selenige Säure source: wikidata, accessed: 2019-09-02, Monohydrated selenium dioxide source: ICSC, accessed: 2019-09-04
    • Appearance: White hygroscopic crystals source: wikipedia, accessed: 2019-09-27; Colourless hygroscopic crystals source: ICSC, accessed: 2019-09-04
  • Zn
    • Names: Zinc source: wikidata, accessed: 2019-09-07, Zinc powder (pyrophoric) source: ICSC, accessed: 2019-09-04, Zn source: wikidata, accessed: 2019-09-07
    • Appearance: Grey-to-blue powder source: ICSC, accessed: 2019-09-04
  • HCl – Chlorane source: wikipedia, accessed: 2019-09-27, Hydrogen chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Hydrochloric acid source: wikipedia, accessed: 2019-09-27source: NIOSH NPG, accessed: 2019-09-02, M source: wikipedia, accessed: 2019-09-27, Uriatic acid source: wikipedia, accessed: 2019-09-27
    • Appearance: Colorless, transparent liquid, fumes in air if concentrated 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; Colorless to slightly yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • ZnCl2 – Zinc chloride source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Zinc(II) chloride source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02, Zinc dichloride source: wikipedia, accessed: 2019-09-28source: ICSC, accessed: 2019-09-04, Butter of zinc source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Appearance: White crystalline solid | hygroscopic and very deliquescent source: wikipedia, accessed: 2019-09-28; White hygroscopic odourless solid in various forms source: ICSC, accessed: 2019-09-04; White particulate dispersed in air. source: NIOSH NPG, accessed: 2019-09-02
  • Se
    • Names: Selenium source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Se source: wikidata, accessed: 2019-09-07, Selen source: wikidata, accessed: 2019-09-07
    • Appearance: Grey solid in various forms source: ICSC, accessed: 2019-09-04; Amorphous or crystalline, red to gray solid. [Note: Occurs as an impurity in most sulfide ores.] 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