4 H2SO4 (aq) + 2 FeCl2 (aq) 2 H2O (l) + 4 HCl (aq) + SO2 (aq) + Fe2(SO4)3 (s)

This is an oxidation-reduction (redox) reaction:

SVI + 2 e- SIV (reduction)

2 FeII - 2 e- 2 FeIII (oxidation)

H2SO4 is an oxidizing agent, FeCl2 is a reducing agent.

This is a precipitation reaction: Fe2(SO4)3 is the formed precipitate.

Reactants:

  • H2SO4Sulfuric 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
  • FeCl2Iron(II) chloride source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04, Iron dichloride source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04
    • Other names: Ferrous chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Rokühnite source: wikipedia, accessed: 2019-09-27, [FeCl3] source: wikidata, accessed: 2019-09-02, FeCl3 source: wikidata, accessed: 2019-09-02
    • Appearance: Tan solid (anhydrous) | Pale green solid (di-tetrahydrate) source: wikipedia, accessed: 2019-09-27; White-to-light-green hygroscopic crystals source: ICSC, accessed: 2019-09-04

Products:

  • 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
  • HClChlorane source: wikipedia, accessed: 2019-09-27, Hydrogen chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Hydrochloric acid source: wikipedia, accessed: 2019-09-27source: NIOSH NPG, accessed: 2019-09-02, Hydrochloric acid gas source: wikipedia, accessed: 2019-09-27, HCl source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless, transparent liquid, fumes in air if concentrated source: wikipedia, accessed: 2019-09-27; Colorless gas source: wikipedia, accessed: 2019-09-27; Colourless compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Colorless to slightly yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02
  • SO2Sulfur 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
  • Fe2(SO4)3Iron(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