6FeSO4 + 4H2SO4 + 2KNO3 → 3Fe2(SO4)3 + 2NO + K2SO4 + 4H2O
Iron(II) sulfate react with sulfuric acid and potassium nitrate to produce iron(III) sulfate, nitric oxide, potassium sulfate and water. Iron(II) sulfate and sulfuric acid - concentrated solutions. The reaction takes place in a boiling solution.