4 FeSO₄ + O₂ + 2 H₂O → 4 (FeOH)SO₄

This is an oxidation-reduction (redox) reaction:

FeSO₄ is a reducing agent, O₂ is an oxidizing agent.

Reactants:

• FeSO₄ – Iron(II) sulphate
  • Other names: Iron(II) sulfate , Ferrous sulfate , Green vitriol ... show moreIron vitriol , Copperas , Melanterite , Szomolnokite , Ferrous sulfate , Iron sulfate (1:1) , Iron(II) sulfate (1:1) , Ferrous sulfate (anhydrous) , Ferrous sulfate (anh.) , Iron(2+) sulfate (anh.) , FeSO4 , Fe(II)SO4 , Ferrous sulfate anhydrous show less
  • Appearance: White crystals (anhydrous) | White-yellow crystals (monohydrate) | Blue-green crystals (heptahydrate)
• O₂
  • Names: Dioxygen , Oxygen , Oxygen (liquefied) ... show moreO2 , O₂ , Oxygen gas , Molecular oxygen , Oxygen, refrigerated liquid , LOX , Liquid oxygen show less
  • Appearance: Odourless compressed gas ; Liquefied gas. colourless-to-blue extremely cold liquid
• H₂O – Water, oxidane
  • Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide ... show moreDihydrogen monoxide (DHMO) (systematic name) , Hydrogen monoxide , Dihydrogen oxide , Hydric acid , Hydrohydroxic acid , Hydroxic acid , Hydrol , Μ-oxido dihydrogen , Κ1-hydroxyl hydrogen(0) show less
  • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas

Products:

• (FeOH)SO₄