2FeSO4 + 2KNO2 + 2H2SO4 → Fe2(SO4)3 + 2NO + K2SO4 + 2H2O
Iron(II) sulfate react with potassium nitrite and sulfuric acid to produce iron(III) sulfate, nitric oxide, potassium sulfate and water. Sulfuric acid - diluted solution. Potassium nitrite and iron(II) sulfate - solid.