6 Fe(SO₄) + K₂(Cr₂O₇) + 7 H₂SO₄ → 3 Fe₂(SO₄)₃ + 7 H₂O + K₂(SO₄) + Cr₂(SO₄)₃

This is an oxidation-reduction (redox) reaction:

Fe(SO₄) is a reducing agent, K₂(Cr₂O₇) is an oxidizing agent.

Reactants:

• Fe(SO₄)
• K₂(Cr₂O₇)
• H₂SO₄ – Sulfuric acid
  • Other names: Oil of vitriol , Sulfuric acid, concentrated (> 51% and < 100%) , H2SO4 ... show moreSulphuric acid , Battery acid , Hydrogen sulfate , [SO2(OH)2] , [S(OH)2O2] , Sulfuric acid (aqueous) show less
  • Appearance: Clear, colorless liquid ; Odourless colourless oily hygroscopic liquid ; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.]

Products:

• Fe₂(SO₄)₃ – Iron(III) sulfate
  • Other names: Ferric sulfate , Sulfuric acid , Iron(3+) salt (3:2) ... show moreDiiron tris(sulphate) , Iron tersulfate , Iron sesquisulfate , Iron persulfate , Ferric tersulfate , Ferric sesquisulfate , Ferric persulfate , Diiron trisulfate , Iron(III) sulfate(VI) , Ferric sulfate anhydrous show less
  • Appearance: Grayish-white crystals
• 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
• K₂(SO₄)
• Cr₂(SO₄)₃ – Chromium(III) sulfate
  • Other names: Basic chromium sulfate , Chromic sulfate
  • Appearance: Reddish-brown crystals (anhydrous), purple crystals (hydrated)