# Why and how do we get NH4NO3 when reacting very dilute HNO3 with Zn?

From Russian Wikipedia's article on nitric acid:

It's clear that as we decrease the concentration of nitric acid, we get more and more reduced nitrogen: in $\ce{NO2}$, the oxidation state of N is ($\mathrm{+4}$), then it goes to zero in $\ce{N2}$ (when we use $\mathrm{10\%}$ strong $\ce{HNO3}$).

But why all of a sudden we get $\ce{NH4NO3}$? In $\ce{NH4}$, the oxidation of $\ce{N}$ is ($\mathrm{-3}$), in $\ce{NO3}$, the oxidation state is ($\mathrm{+5}$). So the overall oxidation increases by $\mathrm{2}$.

I wonder how this ammonium nitrate is generated, i.e. where the ammonium ion evolves from.

• Ammonium ion is generated from $\ce{HNO3}$ in full accordance with the previous trend which you correctly summarized as follows: as we decrease the concentration of nitric acid, we get more and more reduced nitrogen. – Ivan Neretin Feb 17 '16 at 7:54
• Very well you got answer for your question. Here, best thing is that you can answer your own question. So, feel free to write that here. – Vivek Ji Feb 19 '16 at 13:39