Na2SeO3 (aq) + 2 NaOH (aq) + Cl2 (g) Na2SeO4 (aq) + 2 NaCl (aq) + H2O (l)

This is an oxidation-reduction (redox) reaction:

SeIV - 2 e- SeVI (oxidation)

2 Cl0 + 2 e- 2 Cl-I (reduction)

Na2SeO3 is a reducing agent, Cl2 is an oxidizing agent.

Reactants:

  • Na2SeO3
    • Names: Sodium selenite source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Disodium selenite source: ICSC, accessed: 2019-09-04, Selenious acid, disodium salt source: ICSC, accessed: 2019-09-04, Disodium selenium trioxide source: ICSC, accessed: 2019-09-04
    • Appearance: Colourless solid source: wikipedia, accessed: 2019-09-27; Hygroscopic solid in various forms 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
  • Cl2
    • Names: Chlorine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Molecular chlorine source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: Greenish-yellow compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Greenish-yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • Na2SeO4
    • Names: Sodium selenate source: wikidata, accessed: 2019-09-02, Sodium selenium oxide source: wikidata, accessed: 2019-09-02, Selenic acid, disodium salt source: wikidata, accessed: 2019-09-02
  • NaClSodium chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: {{unbulleted list source: wikipedia, accessed: 2019-09-27, Salt source: wikidata, accessed: 2019-09-02, Table salt source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless cubic crystals source: wikipedia, accessed: 2019-09-27
  • H2OWater, 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