2 FeI2 (aq) + 6 H2SO4 (aq) → 3 SO2 (aq) + 2 I2 (s) + Fe2(SO4)3 (s) + 6 H2O (l)

This is an oxidation-reduction (redox) reaction:

3 SVI + 6 e- → 3 SIV (reduction)

4 I-I - 4 e- → 4 I0 (oxidation)

2 FeII - 2 e- → 2 FeIII (oxidation)

H2SO4 is an oxidizing agent, FeI2 is a reducing agent, FeI2 is a reducing agent.

This is a precipitation reaction: I2 andFe2(SO4)3 is the formed precipitate.

Reactants:

  • FeI2 – Iron(II) iodide source: wikipedia, accessed: 2019-09-27
    • Other names: Ferrous iodide source: wikidata, accessed: 2019-09-02
    • Appearance: White to off-white powder 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

Products:

  • SO2 – Sulfur dioxide source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Sulfurous anhydride source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sulphur dioxide source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-02, Sulfurous acid anhydride source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: Colorless gas source: wikipedia, accessed: 2019-09-28; Colourless gas or compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02
  • 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
  • Fe2(SO4)3 – Iron(III) sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Ferric sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Sulfuric acid source: wikipedia, accessed: 2019-09-27, Iron(3+) salt (3:2) source: wikipedia, accessed: 2019-09-27
    • Appearance: Grayish-white crystals source: wikipedia, accessed: 2019-09-27
  • 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