6 Na2SO4 (aq) + I2 (s) + 5 Cl2 (g) + 6 H2O (l) → 2 NaIO3 (aq) + 10 NaCl (aq) + 6 H2SO4 (aq)

This is an oxidation-reduction (redox) reaction:

2 I0 - 10 e- → 2 IV (oxidation)

10 Cl0 + 10 e- → 10 Cl-I (reduction)

I2 is a reducing agent, Cl2 is an oxidizing agent.

Reactants:

  • 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
  • I2
    • Names: Iodine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Jod source: ICSC, accessed: 2019-09-04, Iode source: ICSC, accessed: 2019-09-04
    • Appearance: Bluish black or dark purple crystals with pungent odour source: ICSC, accessed: 2019-09-04; Violet solid with a sharp, characteristic odor. 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
  • 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

Products:

  • NaIO3
    • Names: Sodium iodate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Iodic acid source: wikipedia, accessed: 2019-09-27, Sodium salt source: wikipedia, accessed: 2019-09-27
    • Appearance: White orthorhombic crystals source: wikipedia, accessed: 2019-09-27
  • NaCl – Sodium 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
  • 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