6FeSO4 + 4NO2 + 3H2SO4 → N2 + 3Fe2(SO4)3 + 2HNO3 + 2H2O
Iron(II) sulfate react with nitrogen dioxide and sulfuric acid to produce nitrogen, iron(III) sulfate, nitric acid and water. Iron(II) sulfate - concentrated solution. Sulfuric acid - diluted solution.