2Fe(NH4)2(SO4)2 + H2SO4 + 2HNO3 → Fe2(SO4)3 + 2(NH4)2SO4 + 2NO2 + 2H2O
Diammonium-iron(II) sulfate react with sulfuric acid and nitric acid to produce iron(III) sulfate, ammonium sulfate, nitrogen dioxide and water. The reaction takes place in a boiling solution. Sulfuric acid - diluted solution. Nitric acid - concentrated solution.