H2SO3 + 2 KMnO4 + 4 NaOH → K2MnO4 + Na2MnO4 + 3 H2O + Na2SO4

This is an acid-base reaction (neutralization): H2SO3 is an acid, NaOH is a base.

This is an oxidation-reduction (redox) reaction:

2 MnVII + 2 e- → 2 MnVI (reduction)

SIV - 2 e- → SVI (oxidation)

KMnO4 is an oxidizing agent, H2SO3 is a reducing agent.

Reactants:

  • 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
  • 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
  • NaOH
    • Names: Sodium hydroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Caustic soda source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Lye source: wikidata, accessed: 2019-09-02
    • Appearance: White, waxy, opaque crystals source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04; Colorless to white, odorless solid (flakes, beads, granular form). source: NIOSH NPG, accessed: 2019-09-02

Products:

  • K2MnO4 – Potassium manganate(VI) source: wikipedia, accessed: 2019-09-27
    • Other names: Potassium manganate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: Green crystals (darkening with time) source: wikipedia, accessed: 2019-09-27
  • Na2MnO4
  • 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
  • Na2SO4
    • Names: Sodium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sodium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Sulfate of sodium source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid | hygroscopic source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04