Features of the reaction of nitric acid with metals.

Concentrated nitric acid reacts with metals from Li – Mg to form nitric oxide – N2O,
From Be – Pb, nitrogen oxide – NO is formed; from Cu – Ag nitrogen dioxide – NO2 is released. Here are some examples involving concentrated nitric acid:
Cu +4 HNO3 (K) = CU (NO3) 2 + 2NO2 + 2H2O
Diluted nitric acid with metals from Li – Mg to form NH4NO3, metals from Be – Pb to form N2, N2O; metals Cu-Ag form nitrogen oxide – NO.
Let’s write the equations:
4Mn + 10HNO3 (dil.) = 4Mn (NO3) 2 + N2O + 5H2O;
4Zn + HNO3 (dil.) = 4Zn (NO3) 2 + NH4NO3 + 3H2O.