4 KOH + 3 KNO₃ + Fe₂O₃ → 2 H₂O + 3 KNO₂ + 2 K₂FeO₄

This is an oxidation-reduction (redox) reaction:

KNO₃ is an oxidizing agent, Fe₂O₃ is a reducing agent.

Reactants:

• KOH – Potassium hydroxide
  • Other names: Caustic potash , Lye , Potash lye ... show morePotassia , Potassium hydrate , KOH , E525 , Potassium lye , Lye [Potassium hydroxide] show less
  • Appearance: White solid, deliquescent ; White hygroscopic solid in various forms ; Odorless, white or slightly yellow lumps, rods, flakes, sticks, or pellets. [Note: May be used as an aqueous solution.]
• KNO₃ – Potassium nitrate
  • Other names: Saltpeter , Saltpetre , Nitrate of potash ... show moreNitric acid, potassium salt , Niter , Salt peter , Nitre show less
  • Appearance: White solid ; Colourless-to-white crystalline powder
• Fe₂O₃ – Iron(III) oxide
  • Other names: Ferric oxide , Hematite , Ferric iron ... show moreRed iron oxide , Rouge , Maghemite , Colcothar , Iron sesquioxide , Rust , Ochre , Iron oxide dust and fume (as Fe) , Iron oxide red , Red oxide , Anhydrous ferric oxide , Iron (III) oxide , Diiron trioxide , Iron trioxide , Ferric sesquioxide , Iron(III) oxide [Iron oxide dust and fume (as Fe)] , Iron(III)oxide [Rouge] show less
  • Appearance: Red-brown solid ; Reddish brown-to-black crystals or powder ; Reddish-brown solid. [Note: Exposure to fume may occur during the arc-welding of iron.] ; A fine, red powder of ferric oxide. [Note: Usually used in cake form or impregnated in paper or cloth.]

Products:

• 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
• KNO₂
  • Names: Potassium nitrite , Nitrous acid potassium salt
  • Appearance: White or slight yellow solid | deliquescent ; White-to-yellow deliquescent solid in various forms
• K₂FeO₄ – Potassium ferrate(VI)
  • Other names: Potassium ferrate , Dipotassium ferrate
  • Appearance: Dark purple solid