Question

What is the nitrogen oxidation state in ammonia?

Answer 1

Ain't we got `stackrel(-III)N`?

Explanation:

We have `NH_3`, and the electrons in each `N-H` are assigned to the most electronegative element, i.e. to nitrogen....and so we gots `N(-III)` and `3xxH(+I)`; the sum of the oxidation numbers is equal to the charge on the resultant species, i.e. `0`.

Note that this makes sense when we speak of dinitrogen reduction, i.e. the reduction of zerovalent dinitrogen gas.......

`1/2stackrel(0)"N"_2(g) +3/2stackrel(0)"H"_2(g) rarr stackrel(-III)" NH"_3(g)`

....which is about the most important inorganic reaction on the planet. Here hydrogen is oxidized to `stackrel(+I)H` and nitrogen reduced to `stackrel(-III)N`. Capisce?