5 Na2SO3 (aq) + 2 KClO3 (aq) + H2SO4 (aq) → 5 Na2SO4 (aq) + K2SO4 (aq) + Cl2 (g) + H2O (l)

This is an acid-base reaction (neutralization): Na2SO3 is a base, H2SO4 is an acid.

This is an oxidation-reduction (redox) reaction:

5 SIV - 10 e- → 5 SVI (oxidation)

2 ClV + 10 e- → 2 Cl0 (reduction)

Na2SO3 is a reducing agent, KClO3 is an oxidizing agent.

This is a gas evolution reaction, Cl2 is the formed gas.

Reactants:

  • Na2SO3 – Sodium sulfite source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Sodium sulphite source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Hypo clear (photography) source: wikipedia, accessed: 2019-09-28, E221 source: wikipedia, accessed: 2019-09-28
    • Appearance: White solid source: wikipedia, accessed: 2019-09-28; White crystals or powder source: ICSC, accessed: 2019-09-04
  • KClO3
    • Names: Potassium chlorate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Potassium chlorate(V) source: wikipedia, accessed: 2019-09-27, Potcrate source: wikipedia, accessed: 2019-09-27, Potassium oxymuriate source: ICSC, accessed: 2019-09-04
    • Appearance: White crystals or powder source: wikipedia, accessed: 2019-09-27; Colourless crystals or white powder source: ICSC, accessed: 2019-09-04
  • H2SO4 – Sulfuric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Oil of vitriol source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sulfuric acid, concentrated (> 51% and < 100%) source: ICSC, accessed: 2019-09-04, H2SO4 source: wikidata, accessed: 2019-09-07
    • Appearance: Clear, colorless liquid source: wikipedia, accessed: 2019-09-27; Odourless colourless oily hygroscopic liquid source: ICSC, accessed: 2019-09-04; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • 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
  • K2SO4
    • Names: Potassium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Potassium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Dipotassium sulfate source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Appearance: White solid source: wikipedia, accessed: 2019-09-27; Colourless-to-white crystals source: ICSC, accessed: 2019-09-04
  • 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
  • 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