# What is the oxidation state of nitrogen in N2O5?

According to the formula it should be +5 but according to its structure shouldn't it be +4? How is it +5 then?

• $5\cdot(-2) + 2\cdot(+5) = 0$ Feb 18, 2016 at 7:44
• But according to the structure it should be + 4 Feb 18, 2016 at 8:32
• No. Why do you think so? Jul 2, 2016 at 17:46
• A coordinate bond gives a formal charge of +1 to N, implying that it effectively gets a raise in oxidation state by +2 Mar 25, 2017 at 17:59

It is +5 .Even by the structure.

Notice that it is a resonance structure of:

Now one of the bonds are coordinate bonds where nitrogen donates BOTH its electrons to oxygen (otherwise, oxygen cannot have a single bond without a negative charge and no peroxy type linkage).

So, while determining oxidation state from the structure :

O.N=+2+2+1=+5

• Your second image is better since it shows formal charges.
– Jan
Jul 2, 2016 at 18:10
• True, but that's not much of an improvement. Evidently, I picked it up for representation purpose. Jul 4, 2016 at 2:37
• Oh, I always advocate properly assigning formal charges to all atoms that need them, which is why I wouldn’t have upvoted your answer if only the first structure were shown ;)
– Jan
Jul 5, 2016 at 0:11