8 H2SeO3 + 2 KMnO4 → 5 H2SeO4 + K2SeO3 + 2 MnSeO3 + 3 H2O

This is an oxidation-reduction (redox) reaction:

2 MnVII + 10 e- → 2 MnII (reduction)

5 SeIV - 10 e- → 5 SeVI (oxidation)

KMnO4 is an oxidizing agent, H2SeO3 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
  • KMnO4 – Potassium manganate(VII) source: wikipedia, accessed: 2019-09-27
    • Other names: Potassium permanganate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Chameleon mineral source: wikipedia, accessed: 2019-09-27, Condy's crystals source: wikipedia, accessed: 2019-09-27
    • Appearance: Purplish-bronze-gray needles | magenta–rose in solution source: wikipedia, accessed: 2019-09-27; Dark purple crystals source: ICSC, accessed: 2019-09-04

Products:

  • H2SeO4 – Selenic(VI) acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Selenic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, H2SeO4 source: wikidata, accessed: 2019-09-02, [SeO2(OH)2] source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless deliquescent crystals source: wikipedia, accessed: 2019-09-27
  • K2SeO3
  • MnSeO3
    • 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