3 Fe+8 HNO3(少量) = 3 Fe(NO3)2 + 2 NO↑ + 4 H2OFe+ 4 HNO3(过量) = Fe(NO3)3 + NO↑ + 2 H2OHNO3少量：3 Fe + 8 H+ + 2 NO3- = 3 Fe2+ + 2 NO↑ + 4 H2OHNO3过量：Fe+ 4 H+ + NO3- = Fe3+ + NO↑ + 2 H2O...